Equine MidSem 2 Exam

Question 1

List the 5 standard radiographs for the distal extremity.

Answer 1

Standing on a block:
- Lateromedial
- Dorsopalmar / dorsoplantar (zero degree)

Standing on a tunnerl (or special block):
- Dorsal 65 degree proximal palmarodistal oblique (distal phalanx / “upright pedal”)
- Dorsal 65 degree proximal palmarodistal oblique (navicular bone)
- Palmaroproximal palmarodistal oblique (navicular skyline)

Question 2

List the 5 standard radiographic view for the fetlock.

Answer 2

Standing:
- Lateromedial (LM)
- Dorsopalmar / plantar (DP) & dorsal 15 degree proximal-palmarodistal oblique
- Dorsolateral palmaromedial oblique (DLPMO)
- Dorsomedial palmarolateral oblique (DMPLO)

Flexed:
- Lateromedial (LM)

Question 3

List the standard views for carpus radiographs.

Answer 3

• Dorsopalmar (DP)
• Lateromedial (LM)
• DMPLO 45
• DLPMO 30
• Flexed lateral
• Skyline distal row

Question 4

Define Lameness.

Answer 4

Any gait abnormality including:
- Limping, hobbling
- Incapacity of properly using one or multiple legs
- Generally caused by pain in horses - eviction strategy
- But can be of mechanic or neurologic origin

Question 5

What are the 10 steps of a lameness exam?

Answer 5

1. History
2. Examination from a distance
3. Palpation
4. Movement
5. Selected tests - manipulation, flexion, direct pressure, wedge
6. Diagnostic analgesia
7. Imaging
8. Diagnosis
9. Management
10. Follow up examination

Question 6

What are the 4 main stages / questions of a lameness examination?

Answer 6

1. Is it lameness?
2. Which leg(s) is it? Notions of primary, secondary & compensatory
3. Which part of the leg(s) is affected?
4. What is the nature of the lesion?

Question 7

What is the difference between primary, secondary & compensatory lameness?

Answer 7

Primary lameness = the leg that hurts the most (real intense lameness)

Secondary lameness = real lameness but intensity is lower than primary

Compensatory lameness = compensatory by other areas / legs due to primary lameness (without the primary lameness the compensatory goes away)

Question 8

What are some of the most common lameness findings?

Answer 8

• 60:40 ratio of FL to HL
• FL up to 95% distal to carpus
• In the foot until proven otherwise
• Owners often think it is behind when it is actually in front & vice versa

Question 9

What does the concept “down on the sound” mean in terms of lameness?

Answer 9

• Head & neck elevate when the lame limb is weight bearing
• Head & neck nod down when the sound limb is weight bearing (“down on the sound”)

Question 10

If the front & hind diagonal limbs (contralateral sides) appear lame / affected - where is primary lameness coming from?

If it is the front & hind limbs on the same side that both appear lame - where is primary lameness coming from?

Answer 10

• If it is front & hind diagonal limbs (contralateral sides) that both appear lame / affected – primary lameness is more likely to come from the front leg
• If it is front & hind limbs on the same side that both appear lame / affected – primary lameness is more likely to come from the hind leg

Question 11

What are the 5 AAEP grades of lameness?

Answer 11

• Grade 0 = not perceptible under any circumstances
• Grade 1 = difficult to observe & not consistently apparent regardless of the circumstances
• Grade 2 = difficult to observe at a walk or when trotting on straight line but consistently apparent under certain circumstances
• Grade 3 = consistently observable at a trot under all circumstances
• Grade 4 = obvious at a walk
• Grade 5 = minimal weight bearing in motion or at rest / complete inability to move

Question 12

Define valgus & varus & possible causes for it.

Answer 12

Valgus = limb deviates laterally distal to a reference point (+/- supernation of carpus / fetlock)

Varus = limb deviates medially distal to a reference point (+/- pronation of carpus / fetlock)

Aetiology:
- Perinatal factors - malposition, placentitis, nutrition, premature or dysmature foals
- Developmental factors - poor nutrition, excessive exercise & trauma
- Most commonly: disproportionate growth of metaphyseal growth plates

Prognosis:
- The more deviation there is the less chance of spontaneous correction

Question 13

Discuss incomplete ossification of carpal / tarsal bones.

Answer 13

• Cuboidal bones have rounded edges
• Common congenital induced angular limb deformity - prematurity or dysmaturity
• Can also occur in normal foals
• Failure to diagnose & treat in 1st few days of life > wedge shaped cuboidal bones > permanent damage
• Diagnosis: radiographs

Treatment:
- Can be manually corrected early on
- Restrict exercise and/or provide external support
- Typically 2-4 weeks to allow for ossification

Question 14

Discuss assymetric growth of metaphysis & epiphysis.

Answer 14

• From birth or develops in 1st weeks / months of life
• Trauma likely major cause of asymmetric growth (asymmetric compression on physis)

Diagnosis:
- Radiographs – asymmetric longitudinal growth of metaphysis or epiphysis

Treatment:
- Physeal growth rates determine rate of correction by modifying chondral growth patterns
- Total amount of growth remaining determines amount of correction achievable
- Chondral growth patterns are modified with: exercise control, farriery (trimming, shoeing), surgery (growth retardation > transphyseal bridging / screws), (growth acceleration > periosteal elevation & transection)
- Treatment method depends on: joint involved, degree of deformity, amount of growth remaining

Treatment for young foals with mild to moderate ALD:
- Stall rest 2 weeks (fetlock), 8 weeks (carpus) > autocorrection possible
- Resolution before end of rapid growth phase - if no resolution > surgery

Question 15

Discuss hyperextension deformity (laxity).

Answer 15

• Toe does not touch the ground
• Congenital or acquired
• Mostly occurs in immature & dysmature foals
• Occurs in hindlimbs > front limbs
• Lack of flexor tone

Aetiology:
- Idiopathic
- Bandaging / casting
- Lack of exercise
- Overgrown hooves

Mild deformities:
- Respond to time & controlled exercise

Moderate & non-responsive deformities:
- Glue on extended heel shoe
- May need to bandage foot & fetlock
- Thick bandages contraindicated > more soft tissue relaxation

*Most foals correct in 2-6 weeks

Question 16

Discuss flexural deformities (“contracted tendons”).

Answer 16

• Length disparity between tendons & bones
• Occurs in forelimbs > hindlimbs
• Structures affected: fetlock, coffin join (DIP), carpus (worse prognosis), determine if SDFT, DDFT, SL

Congenital flexural deformities aetiology:
- Uterine malpositioning
- Teratogens (locoweed, sudan grass, influenza)
- Hypothyroidism
- Neuromuscular disorder
- Genetic factors
- Nutritional imbalances in pregnant mare

Congenital flexural deformities - treatment:
- Begin ASAP
- Younger foals respond better to treatment
- Combine medical & physical therapy
- Farrier - toe extensions
- Oxytetracycline - chelation of calcium ion

Question 17

We need to increase exercise in angular limb deformities or flexural deformities to improve outcome?

Answer 17

• Angular limb deformities we need to decrease exercise
• Vs. Flexural deformities we need to increase exercise

Question 18

Tendonitis / Desmitis - list the different phases of healing.

Answer 18

Inflammatory phase:
- Vascular & cellular

Repair phase:
- Fibroblasts
- Intrinsic & extrinsic repair

Remodelling phase - end result:
- Decreased tensile strength
- Decreased elasticity

Question 19

Discuss the pathogenesis of flexor tendinitis.

Answer 19

• Gradual accumulation of fatigue & progressive impact on collagen – main cause high intensity exercise / training for young horses
• Progressive degeneration of the SDFT
• Excessive stress overstretches & ruptures the collagen fibre bundles
• Low-grade tendon fibre disruption results in an accelerating cycle of inflammation, degeneration & further tendon disruption
• Acute mechanical failure results in partial (usually) tendon rupture
• Muscle is fatigued > prevents it from relaxing > injury

Question 20

Discuss SDFT (Superficial Digital Flexor Tendon) Tendinitis.

Answer 20

Racehorses:
- Up to 30% suffer from tendon injury
- 4% fatal injuries in flat racing
- 11% of fatal injuries in races with jumps

Risk factors:
- Track design, surface type & condition
- Fitness, hoof trimming & shoeing
- Re-injury is common
- Forelimbs most commonly affected

Clinical signs:
- Moderate to severe injury – heat, swelling of SDFT & lameness
- Mild cases – slight pain on firm palpation
- Chronic cases – very large & thickened
- ‘Low bows’ – digital sheath swelling

Diagnosis:
- Clinical signs
- Thermography - low specificity
- Ultrasonography - transverse & longitudinal (must use both)
- Reduced echogenicity - anechoic
- Disruption of linear fibril pattern

Essential / most effective therapy:
- Physiotherapy - cold water hydrotherapy & padded support bandage
- Anti-inflammatory drugs - NSAIDs (or corticosteroids) +/- topical DMSO (Dimethyl Sulfoxide)
- Exercise - stall rest & controlled walking only
- Controlled rehabilitation program - low impact exercise (water walking)

Surgical treatment:
- Tendon splitting - now outdated.
- Superior check ligament desmotomy - transection of superior check ligament (SCL) alters functional length of SDFT & mechanics. Concept = cutting the limiting fibres > longer function of the tendon > transfers centre of pressure / force to whole tendon & muscle (rather than in scar tissue)
- Annular ligament desmotomy

Question 21

How long does it take to recover from a tendon injury vs. a ligament injury?

Answer 21

Tendon injury = ~6 months (“tendon” has 6 letters)

Ligament injury = ~8 months (“ligament” has 8 letters)

Question 22

Descibre how to examine the muscular system.

Answer 22

• History
• Physical exam - inspection (asymmetry), palpation (of several muscles) & percussion (with a hammer), gait analysis

Biochemical parameters:
- CK - increased CK related to cell lysis. >100,000 IU/L, peak at 4-6h, T1/2 12h, abnormal is >2-4 fold increase from baseling
- AST - peak 12-24h, T1/2 7-8 days
- LDH - extra analysis but not essential
- Urinalysis - myoglobinuria

Advanced diagnostic testing:
- Plasma Vit E & selenium
- Muscle biopsy - epaxial, gluteal or semimembranosus
- Genetic testing
- Exercise testing - rule out other diseases (e.g. colic due to severe water loss via sweating). Demonstrate mild increase of muscle enzyme activity by provoke test.
- Ultrasonography - depth of muscle
- Electromyography (EMG) - evaluation of muscle tone

Question 23

Define myotonia vs. myopathy vs. muscle atrophy.

Answer 23

Mytonia = something wrong with the muscle tone.

Myopathy = something wrong with the muscle fibre e.g. muscle necrosis (rhabdomyolysis / “tying up”), non-exertional

Muscle atrophy = no muscle present due to a neurogenic or myogenic problem e.g. denervation / dis-use

Question 24

Discuss exertional rhabdomyolysis (“tying up”) syndrome.

Answer 24

History:
- Episodes of post-exercise muscle stiffness
- Changes in training or management

Clinical signs:
- Muscle cramping and/or stiffness
- Muscle pain especially of lumbar & sacral regions
- Sweating, tachycardia, tachypnoea
- Reluctance to move
- Myoglobinuria

Diagnosis:
- Myoglobinuria
- Plasma CK & AST activities

Treatment - supportive:
- IV or oral fluids - maintain urine output to prevent or minimise the nephrotoxic effects of myoglobin & maintain circulation to muscle tissue
- Analgesics - NSAIDs (be careful - kidney insult), opiates
- Keep warm
- Acepromazine
- Vit E / Selenium
- Stall rest

Treatment - long term:
- Rest & regular (daily) turn-out
- Regular daily exercise
- Diet - fat based diet (rice bran, oils) instead of easily digestible carbs, Vit E / Selenium, electrolytes

Question 25

Where is the label correctly placed on a radiograph relative to the limb? - Medially & dorsally - Laterally & caudally - Laterally & dorsally - Medially & caudally

Answer 25

- Laterally & dorsally

Question 26

The dorsal 45 degree proximal distal oblique radiograph of the foot highlights: - The distal border of the navicular bone - The distal interphalangeal joint margins - The proximal margin of the navicular bone - The flexor cortex of the navicular bone

Answer 26

- The proximal margin of the navicular bone

Question 27

Hallmarks of chronic laminitis include: - Reduction of the solar margin-distal phalanx angle, remodelling of the extensor process of the distal phalanx, dorsal distal hoof wedge formation & osteolysis of the tip of the distal phalanx - Increase of the solar margin-distal phalanx angle, dorsal hoof wedge formation, osteolysis of the extensor process of the distal phalanx & rotation of the distal phalanx realtive to the dorsal hoof wall - Dorsal distal hoof wedge formation, remodelling of the palmar processes of the distal phalanx, reduction of the solar margin-distal phalanx angle & rotation of the distal phalanx relative to the dorsal hoof wall - Osteolysis of the tip of the distal phalanx, rotation of the distal phalanx relative to the dorsal hoof wall, increase of the solar margin-distal phalanx angle & dorsal hoof wedge formation

Answer 27

- Osteolysis of the tip of the distal phalanx, rotation of the distal phalanx relative to the dorsal hoof wall, increase of the solar margin-distal phalanx angle & dorsal hoof wedge formation

Question 28

Why is one of the standard projections of the fetlock a dorsal 15 degree proximal-palmar distal oblique & not a dorsal 0 degree proximal-palmar (horizontal DP)? - It elevates the proximal sesamoid bones so that we can see the joint space better - It elevates the proximal sesamoid bones so that we see the proximal phalanx margin chip fractures better - It lowers the proximal sesamoid bones so that we can see the joint space better - It lowers the proximal sesamoid bones so that we can see proximal phalanx margin chip fractures better

Answer 28

- It elevates the proximal sesamoid bones so that we can see the joint space better This angle provides a clearer view of the joint space compared to a horizontal DP view because it reduces superimposition of the sesamoid bones over the joint.

Question 29

Which two projections of the carpus give you the best assessment of the third carpal bone? - The flexed dorsal 30 degree proximal-dorsal distal oblique & DLPMO - The DMPLO & flexed lateral - The flexed dorsal 30 degree proximal-dorsal distal oblique & DMPLO - The flexed dorsal 45 degree proximal-dorsal distal oblique & flexed lateral

Answer 29

- The flexed dorsal 30 degree proximal-dorsal distal oblique & DLPMO

Question 30

Which standard radiographic projection of the tarsus highlights the most common site of osteoarthritis of the distal intertarsal & tarsometatarsal joints? - The DLPMO - The LM - The DP - The DMPLO

Answer 30

- DLPMO

Question 31

Of the following which is more accurate regarding a time dependent antimicrobial? - It has better bactericidal effects than concentration dependent antimicrobials - Doubling the dose (e.g. from 10mg to 20mg) will significantly increase the rate of microbial killing - Doubling the frequency of drug administration (e.g. from q12h to q6h) will likely increase of the rate of microbial killing - It has worse bactericidal effects than concentration dependent antimicrobials

Answer 31

- Doubling the frequency of drug administration (e.g. from q12h to q6h) will likely increase of the rate of microbial killing

Question 32

Which of the following options describes the chronological order & initial treatment of an acutely burned horse best? - Cooling of affected area for 5 min & IV fluid therapy - Cooling of affected area for 20 min & ice boot application - Cooling of affected area for 15 min & systemic analgesia - Cooling of affected area for 10 min & IV clenbuterol administration

Answer 32

- Cooling of affected area for 20 min & ice boot application

Question 33

A two day old colt was diagnosed with a bilateral stage II flexural deformity of the metocarpophalangeal joint. Which of the following statements is correct? - Stall rest & heel extensions will likely correct the deformity - Controlled exercise & stable bandages will correct the deformity within 2 weeks - Medical management using oxytetracycline & NSAIDs has a good prognosis - Inferior check ligament desmotomy has to be considered for the best outcome

Answer 33

- Medial management using oxytetracycline & NSAIDs should be attempted first

Question 34

Please indicate the false statement about impingement of the dorsal spinous process ("kissing spine"). - Surgical resection of one out of two processes is the only long-term treatment available - It is a true arthropathy - It is more frequent between T12 & T18 - It is the most frequent abnormality found on radiographs of the back

Answer 34

- It is a true arthropathy

Question 35

Please indicate the correct statement about the etiopathogenesis of osteoarthritis. - Since the articular cartilage is fully capable to repair itself, weare & tear is rarely the cause of osteoarthritis - Only when left untreated septic arthritis can cause significant damage to the cartilage & lead to osteoarthritis - Ligament damage resulting in major joint instability will certainly lead to osteoarthritis - Malnutrition is a common cause of osteoarthritis, thus ensuring adequate nutrition can practically eliminate osteoarthritis

Answer 35

- Ligament damage resulting in major joint instability will certainly lead to osteoarthritis

Question 36

You diagnose a 4 year old intact male Thoroughbred race horse of an estimated weight of 520kg with a complete, displaced, closed, comminuted fracture of the first phalanx of the right forelimb after he came out 5/5 lame off the race track. - You recommend to the owner to authorise a human euthanasia at the racetrack - After immobilising the leg in a splinted Robert Jones bandage you refer the horse to the nearest referral centre prescribing internal fixation of the fracture with double plating & lag screws - After immobilising the leg in a splinted Robert Jones bandage you refer the horse & recommend transporting him in an open space large truck - After immobilising the leg in a splinted Robert Jones bandage you refer the horse & recommend transporting him in a float with the partitions & with the rear legs facing the trailers' front side

Answer 36

- After immobilising the leg in a splinted Robert Jones bandage you refer the horse & recommend transporting him in a float with the partitions & with the rear legs facing the trailers' front side

Question 37

Please indicate the correct statement about what would be considered a negative response to diagnostic analgesia (both palmar digital nerves (lateral & medial) in the left front limb are blocked) in a horse with a left front lameness. - The left front lameness can no longer be seen after the nerve block - The left front lameness becomes more evident after the nerve block - The left front lameness goes away after the nerve block & the horse now shows a right front lameness - The left front lameness markedly improves after the nerve block

Answer 37

- The left front lameness becomes more evident after the nerve block

Question 38

Which of the following procedures would most specifically localise pain to the fetlock joint? - Metacarpo-phalangeal joint block - Abaxial sesamoid nerve block - Carpo-metacarpal joint block - Low four point (volar) nerve block

Answer 38

- Metacarpo-phalangeal joint block

Question 39

A 3 year old thoroughbred racehorse filly has just returned from an intense work-out & is exhibiting signs of colic (pawing, biting at her sides). The filly is anxious & sweating. Palpation of the hindlimb musculature reveals a painful response. What is the most appropriate initial therapy indicated for this horse? - Cool the horse with iced water - Fluid therapy (IV or enteral) - NSAIDs administration (IV) - Buscopan administration (IV)

Answer 39

- Fluid therapy (IV or enteral)

Question 40

A horse developed acute neurologic signs consistent with spinal ataxia after falling over during a competition. The horse has normal mentation, normal cranial nerve examination & is showing signs of ataxia & proprioceptive deficits on all four limbs (more pronounced in the hindlimbs). What is the most likely region for neurolocalisation? - Sacral - C7-T2 - C1-C6 - Thoracolumbar

Answer 40

- C1-C6

Question 41

Ventrolateral strabismus can be related to a deficit in which cranial nerve? - VI abducent - IV trochlear - III oculomotor - V trigeminal

Answer 41

- III oculomotor

Question 42

Which of the following propositions is false in a case of septic arthritis? - Local treatment is much more likely to achieve a resolution of the infection - Without local treatment there are less chances to get a control of the infection - Identifying the causing agent helps in defining the correct antibiotic protocol - Without arthroscopic joint lavage the sepsis has no chances to be controlled

Answer 42

- Without arthroscopic joint lavage the sepsis has no chances to be controlled

Question 43

Please indicate the correct statement about osteochondrosis in horses. - The proximal interphalangeal joint is the most commonly affected joint - Despite the age of the horses, lesions always progress (get larger) or stay the same overtime - It can be asymptomatic & diagnosed incidentally when the horse is radiographed for sale or any other reason - It is rarely bilateral, so radiographing the contralateral joint is not recommended unless there are external signs of bilateral involvement (e.g. bilateral lameness, bilateral joint effusion)

Answer 43

- It can be asymptomatic & diagnosed incidentally when the horse is radiographed for sale or any other reason

Question 44

After a training session, a thoroughbred colt presents a mild lameness & the swelling illustrated on the picture (SDFT tendinitis). On palpation, the affected area is warm & mildly painful. - This is a desmitis of the suspensory ligament (M. interosseous) & the horse will need to rest 7 to 8 months - This is a desmitis of the palmar annular ligament & the horse needs to rest 4 to 6 months - This is a tendinitis of the superficial digital flexor tendon & the horse needs to rest 4 to 6 month - This is a digital flexor tendon sheath tenosynovitis & the horse should recover in 6 to 8 weeks

Answer 44

- This is a tendinitis of the superficial digital flexor tendon & the horse needs to rest 4 to 6 month

Question 45

Which of the following statements about foot problems in horses is most correct? - Thrush is uncommon & in almost all cases causes severe lameness - Solar penetrating puncture wounds need to be worked up using ultrasonography - Navicular disease is more commonly seen in older horses (>10 years old) & frequently affects both front feet - Foot abscesses typically causes severe lameness which markedly improves within 24 hours with or without treatment

Answer 45

- Navicular disease is more commonly seen in older horses (>10 years old) & frequently affects both front feet

Question 46

Which of the following is the most correct statement regarding the tendon ultrasound below? - Effective treatment options include platelet rich plasma (PRP) & stem cell therapy - The scan shows a core lesion within the Deep Digital Flexor Tendon (DDFT) - Once appropriately treated, a full recovery can be expected with a low rate of re-injury - A CT scan of the tendon would have been the diagnostic gold standard & revealed the full extent of the lesion

Answer 46

- Effective treatment options include platelet rich plasma (PRP) & stem cell therapy

Question 47

Please indicate the option with the correct names of the anatomical structures indicated by the tip of each arrow in the images above.

Answer 47

1 = metacarpo-phalangeal joint, 2 = proximal sesamoid bone, 3 = suspensory ligament, 4 = distal sesamoidean ligament, 5 = 3rd metacarpal bone

Question 48

Which of the following is the most important complication to be ruled out when assessing the puncture wound of the sole shown in the image below? (Picture of nail just next to frog) - Laminitis - Foot abscess - Septic navicular bursitis & or distal inter-phalangeal joint - Pedal osteitis - Sub solar bruise

Answer 48

- Septic navicular bursitis & or distal inter-phalangeal joint

Question 49

A horse is presented with a laceration to the distal limb. There was obvious leakage of fluid through the wound when the distal interphalangeal joint was injected with sterile isotonic electrolyte solution under pressure (as shown in the picture). Which of the following statements is most correct? - Daily joint lavage with a powerful antiseptic would likely reduce the risk of osteoarthritis & permanent lameness - Prolonged systemic administration of broad spectrum antibiotics (e.g. amikacin & penicillin) would be enough to eliminate the risk of osteoarthritis & permanent lameness - Enrofloxacin would be a good antimicrobial choice for intra-articular administration in order to reduce the risk of osteoarthritis & permanent lameness - Regional limb perfusion with gentamicin would be a relatively inexpensive treatment to reduce the risk of osteoarthritis & permanent lameness

Answer 49

- Regional limb perfusion with gentamicin would be a relatively inexpensive treatment to reduce the risk of osteoarthritis & permanent lameness

Question 50

The dorsal 45 degree proximal distal oblique radiograph of the foot highlights: - The distal border of the navicular bone - The distal interphalangeal joint... - The proximal margin of the navicular bone

Answer 50

- The proximal margin of the navicular bone

Question 51

Which standard radiographic projection of the tarsus highlights the most common site of osteoarthritis of the distal intertarsal & tarsometatarsal joints? - DP - DMPLO - DLPMO - LM

Answer 51

- DLPMO

Question 52

This projection of the tarsus is most useful for examination of?

Answer 52

The distal intermediate ridge of the tibia & the lateral trochlear ridge of the talus

Question 53

When ruling out synovial involvement after a deep heel bulb laceration, which of the following diagnostic imaging techniques would be most appropriate?

Answer 53

Contrast radiography

Question 54

When is cryotherapy used as a treatment for laminitis? - During the acute phase to maintain the lamellar temperature below 10 degrees for at least 48 hours - During the chronic phase to maintain the lamellar temperature below 0 degrees for at least 48 hours - For chronic endocrinopathic laminitis with a goal of maintaining the lamellar temperature below 10 degrees for at least 48 hours

Answer 54

- During the acute phase to maintain the lamellar temperature below 10 degrees for at least 48 hours

Question 55

Choose the best definitive diagnostic test for a horse with suspected polysaccharide storage myopathy-1 (PSSM-1). - Serum CK & AST concentrations, 4 to 6 hours after 15 min of exercise - Genetic test for the GYS1 variant on hair or blood samples

Answer 55

- Genetic test for the GYS1 variant on hair or blood samples

Question 56

Which of the following describes upper motor neuron (UMN) & lower motor neuron (LMN) deficits most accurately?

Answer 56

UMN = spasticity, normal to increased...

Question 57

What is the best treatment for a horse with cranial trauma (traumatic brain injury)? - Hypertonic saline IV - Systemic antimicrobials IV

Answer 57

- Hypertonic saline IV

Question 58

What is the most likely diagnosis of a horse with protrusion of the third eyelid, a "saw horse stance" & elevated tail head?

Answer 58

Tetanus

Question 59

A 3 year old thoroughbred race horse filly has just returned from an intense work-out & is exhibiting signs of colic (pawing, biting at her sides). The filly is anxious & sweating. Palpation of muscle groups of her hind limbs reveals a painful response. What is the most important initial therapy indicated for this horse?

Answer 59

Fluid therapy (IV or oral)

Question 60

Please indicate the correct statement about the etiopathogenesis of osteoarthritis.

Answer 60

Muscle damage leading to joint damage & OA

Question 61

A 6 year old horse has fallen violently in its paddock 2 hours before you evaluate it for the complaints of dullness, stumbling & "not knowing where his feet are." The owners are scared because he appears unsteady & they call you. Which of the following describes best the chronology for your initial approach?

Answer 61

You administer a sedative & anti-inflammatory & perform physical exam, start the horse on osmotic fluids & gather information

Question 62

A horse showing hindlimb ataxia, bladder paresis, perineal hypalgesia but normal mentation & no muscle tremors is most likely to have which virus? - Equine Herpes Virus 1 - Kunjin Virus

Answer 62

- Equine Herpes Virus 1

Question 63

A two day old colt was diagnosed with a bilateral stage contracture of the distal interphalangeal joint. Which of the following statements is correct? - Medial management using oxytetracycline & NSAIDs should be attempted first - Stall rest & heel extensions will likely correct the deformity - Superficial digital flexor tendon tenotomy has to be considered for a timely resolution

Answer 63

- Medial management using oxytetracycline & NSAIDs should be attempted first

Question 64

Watch this video. Define which leg is lame & the AAEP grade of lameness.

Answer 64

Left front - grade 2/5

Question 65

Watch this video. Define which leg is lame and the AAEP grade of lameness.

Answer 65

Right hind - grade 1/5

Question 66

Which describes the best overall management for a horse with signs of tetanus? - Turn off lights of stable, muscle relaxants, metronidazole (25mg/kg), IV fluid therapy, tetanus anti-toxin - Place horse in sling, anti-seizure medication, penicillin (50,000 IU/kg), IV fluid therapy, booster tetanus toxoid - Turn off lights of stable, anti-inflammatory medication, penicillin (50,000 IU/kg), IV fluid therapy, tetanus anti-toxin - Place horse in sling, muscle relaxants, metronidazole (25mg/kg), IV parenteral nutrition, booster tetanus toxoid

Answer 66

- Turn off lights of stable, muscle relaxants, metronidazole (25mg/kg), IV fluid therapy, tetanus anti-toxin

Question 67

Based on the events occurring during any neurological insult (regardless of its classification) which are the main goals for treating neurological diseases?

Answer 67

To reduce the inflammatory repsonse & intracranial pressure, to minimise external stimuli, to ensure supportive care, to be aware of potential residual neurological damage

Question 68

Which are signs of vestibular ataxia & examples of disease causing it?

Answer 68

Head tilt towards the lesion, circling towards the lesion, wide based stance, horizontal nystagmus & normal menace response. Guttural pouch disease & otitis media / interna can cause this.

Question 69

Which of the following factors affect the prognosis most significantly for a good outcome after a proximal limb long bone fracture? - A body weight higher than 250-300kg - The fracture has been diagnosed & referred after 8 days - The horse has to travel 6 hours to the nearest referral centre - The horse is older than 8 years old

Answer 69

- A body weight higher than 250-300kg

Question 70

Which of the following combination of data gives you the best confidence to confirm that a synovial fluid collection is indicating sepsis? - The nucleated cell count, % of neutrophils & total proteins - The turbidity of the synovial fluid, distension of the synovial structure & nucleated cell count - The degree of lameness of the horse, the culture of the synovial fluid & its macroscopic aspect - The synovial lactate, the synovial fluid glucose & its pH

Answer 70

- The nucleated cell count, % of neutrophils & total proteins

Question 71

Which of the following propositions is false in a case of septic arthritis? - Without arthroscopic joint lavage, sepsis has no chance to be controlled - Local treatment is much more likely to achieve a resolution of the infection - Identifying the causing agent helps in defining the correct antibiotic protocol - Without local treatment, there is less chance to control the infection

Answer 71

- Without arthroscopic joint lavage, sepsis has no chance to be controlled

Question 72

Which of the following propositions is true? - Surgical ankylosis (arthrodesis) is a good means to relieve joint pain for high range of motion joints suffering end stage degenerative joint disease - Surgical ankylosis (arthrodesis) is the method of choice to restore the function of the metacarpophalangeal joint of sport horses with end-stage degenerative joint disease - Surgical ankylosis (arthrodesis) is the only option to relieve pain associated with end-stage degenerative joint disease - Surgical ankylosis (arthrodesis) means the end of the sport career of the horses in all cases

Answer 72

- Surgical ankylosis (arthrodesis) is a good means to relieve joint pain for high range of motion joints suffering end stage degenerative joint disease

Question 73

Concerning dorsal spinous process impingement (DSPI - kissing spine) which is a false assumption? - Dorsal spinous process impingement is a true arthropathy - Dorsal spinous process impingement is more frequent between T12-T18 - A surgical resection of one out of 2 processes is the only long-term treatment available - It is the most frequent abnormality finding on radiographic examination of the back in horses

Answer 73

- Dorsal spinous process impingement is a true arthropathy

Question 74

Which set of neurologic diseases warrants isolation of the diseased horses? - Australian bat lyssa virus (ABLV, rabies), equine herpes myeloencephalopathy & hendra virus infection - Australian bat lyssa virus (ABLV, rabies), equine degenerative myelopathy & botulism - Equine degenerative myelopathy, hendra virus infection & australian bat lyssavirus (ABLV, rabies)

Answer 74

- Australian bat lyssa virus (ABLV, rabies), equine herpes myeloencephalopathy & hendra virus infection

Question 75

A 14 month old quarter horse filly has had intermittent episodes of sweating, muscle weakness & fasciculations, which have led to recumbency on 2 occasions. The filly is able to recover & stand within 30 minutes of each episode. You collect a blood sample from the filly & find the following: massively increased CK (normal Na+, normal Cl-, normal AST) Which of the following diagnoses is most likely? - Hyperkalemic periodic paralysis (HYPP) - Subclinical polysaccharide storage myopathy (PSSM) - Neurologic disease associated with cervical vertebral instability - Nutritional myodegeneration

Answer 75

- Hyperkalemic periodic paralysis (HYPP)

Question 76

One of the methods to evaluate the possible presence of muscular problems such as Polysaccharide Storage Myopathy (PSSM) in performance horses is to check their post-exercise response. This is best done by: - Measuring serum CK & AST activity levels 4 to 6 hours after 15 min of exercise - Measuring serum CK & AST activity levels 15 minutes after 30 min of exercise - Measuring CK levels 4h after exercise but not AST since it has a long half life - Measuring serum CK & AST activity only in horses with chronic muscle pain at rest

Answer 76

- Measuring serum CK & AST activity levels 4 to 6 hours after 15 min of exercise

Question 77

Sudden signs of dysphagic & muscle fasciculation in a horse without fever is most likely caused by: - Kunjin encephalitis virus infection - Hendra virus infection - Exertional rhabdomyolysis - Hyperkalemia periodic paralysis

Answer 77

- Kunjin encephalitis virus infection

Question 78

Please indicate the correct statement about horse gaits: - Trot is a two beat symmetric gait without a suspension phase - Gallop is a four beat symmetric gait with a suspension phase - Canter is a three-beat assymetric gait with a suspension phase - Walk is a four beat symmetric gait with a suspension phase

Answer 78

- Canter is a three-beat assymetric gait with a suspension phase

Question 79

Please indicate the correct statement about tendons and ligaments? - Even in mature horses, healing is fast because of the high metabolism and rapid turnover of tendons and ligaments - Paratenon is a layer of loose connective tissue surrounding a tendon with the function of facilitating tendon gliding - Tendon sheath is a synovial structure covering no more than half of the circumference of a tendon - Tendon and ligament injuries are always caused by a single traumatic episode leading to excessive tension on the ligament

Answer 79

- Paratenon is a layer of loose connective tissue surrounding a tendon with the function of facilitating tendon gliding

Question 80

Please indicate the correct statement about what would be considered a negative response to a flexion test in a horse with right hind lameness. - The original right lameness because more evident after the left hind limb is flexed - The original right hind lameness because less evident after the left hind limb is flexed - The original right hind lameness does not change after the right hind limb is flexed - The original right hind lameness because less evident after the right hind limb is flexed

Answer 80

- The original right hind lameness does not change after the right hind limb is flexed

Question 81

Please indicate the most distal nerve block that would likely anaesthetise the whole fetlock joint in a forelimb? - Palmar digital nerve block at the level of the proximal sesamoid bones - Low 4 point block (palmar nerves and palmar metacarpal nerves in the distal half of the canon) - High 4 point block (palmar nerves and palmar metacarpal nerves close to the carpometacarpal joint ) - Lateral palmar nerve blocked at the level of the accessory carpal bone

Answer 81

- Low 4 point block (palmar nerves and palmar metacarpal nerves in the distal half of the canon)

Question 82

Please indicate the correct statement about the morphology and physiology of synovial joints. - The only function of the synovial fluid is lubrication of articular cartilages - Synovial fluid is produced by chondrocytes - In mature horses, the whole articular cartilage in is supplied by vessels and nerves - The subchondral bone provides physical support to the articular cartilage and nutrition to the deep layers of the articular cartilage

Answer 82

- The subchondral bone provides physical support to the articular cartilage and nutrition to the deep layers of the articular cartilage

Question 83

Please indicate the correct statement about foot problems in horses. - Navicular disease is more commonly seen in older horses and in horses with small feet and/or low heels - Avulsion fractures of the extensor process of the distal phalanx is typically seen in older horses - Foot abscesses typically causes severe lameness which markedly improves within 24 hours even when drainage is not established - Canker is a benign neoplastic condition affecting the frog which can only be managed by aggressive debridement

Answer 83

- Navicular disease is more commonly seen in older horses and in horses with small feet and/or low heels

Question 84

Please indicate which would be a reasonable therapeutic approach for a valuable 1 month old foal and moderate carpus valgus and secondary fetlock varus affecting the right front limb. - Confine the foal to a stall, wait and hope that the angular limb defomities will resolve spontaneously over time. - Wait 5 months and perfom transphyseal bridging with a transphyseal screw on lateral side of the distal radius an on the medial side of the proximal phalanx - Immediately perform transphyseal bridign with a tranphyseal screw on the medial side of the distal radious and wait for the varus deformity of the fetlock to improve over time - Immediately preform transphyseal bridging with a transphyseal screw on the medial side of the distal radiu and on the lateral side of the proximal phalanx

Answer 84

- Immediately preform transphyseal bridging with a transphyseal screw on the medial side of the distal radiu and on the lateral side of the proximal phalanx

Question 85

The photo below shows the front limbs of a 15 year old mare with left front limb lameness that is unable to touch the groun with the heels of the left front foot for the last 4 months. What is the correct statement about the name of the deformity in the left front limb and the likely cause(s) of this deformity? - Contracted digital flexor tendons attributed to sudden increase in energy and protien in the diet about 6 months ago - Laxity of the digital extensor tendons attributed to chornic and severe toe pain - Contracted digital flexor tendons attributed to choronic and seevere heel pain - Laxity of the digital extensory tendons attributed to chornic and severe heel pain

Answer 85

- Contracted digital flexor tendons attributed to choronic and seevere heel pain

Question 86

A horse with an obvious (AAEP grade 3) left front lameness was subjected to a palmar digital block of the left forelimb. Wat the view showing the horse at the trot after the nerve block and indicate the correct statement about the response to the block. - The block resolved the left front limb lameness and the horse is not longer lame - The block resolved the left front limbe lamness and now the horse has a right front AAEP grade 3 lameness - The block did not change anything and the horse still has a left front AAEP grade 3 lameness - The block did not improve the lameness. Actually the horse now has a grade 5 left front AAEP lameness/

Answer 86

- The block did not change anything and the horse still has a left front AAEP grade 3 lameness

Question 87

Please indicate the correct statement about the aetiopathogenesis of osteoarthritis:

Answer 87

Ligament damage resulting in major joint instability will certainly lead to osteoarthritis

Question 88

Please indicate the best therapeutic approach for a 1 year old horse with sudden onset of right hind lameness and right hock effusion with radiographic evidence of a loose osteochondral garment in the right Tarsocural joint: - Arthroscopic surgery - Prolonged stall rest - Immobilisation - Corrective trimming and shoeing

Answer 88

- Arthroscopic surgery

Question 89

What is the best management option in case of equine Motor Neuron Disease (EMND)? - Increase the amount of pellets, hay and supplement with Vitamin E - Decrease the amount of pellets and supplement with vitamin E - Increase the amount of hay - Deceased the amount of pellets, hay and add corn oil

Answer 89

- Increase the amount of pellets, hay and supplement with Vitamin E

Question 90

You are asked to examine a Warmblood mare of 5 years old with an abnormal gait especially while cantering the mare is showing a ‘hopping gait’. You suspect the horse of Australian Stringhalt. What is the next abnormal finding during clinical examination and diagnostic testing? - No abnormalities in history, normal clinical signs and normal findings at electromyography (EMG) examination - Normal clinical signs, severely increased muscle enzyme activities (CK and AST activities) and normal EMG findings - Normal clinical signs, no abnormal findings at blood gas analysis and abnormal findings at electromyography (EMG) examination - History includes toxic plants in the paddock, and decreased appetite; blood analysis shows increased liver enzyme activities (AST and GGT).

Answer 90

- Normal clinical signs, no abnormal findings at blood gas analysis and abnormal findings at electromyography (EMG) examination

Question 91

A 12 year old gelding present with acute ataxia (incoordination) in all four limbs. A nasal swab reveals a positive EHV-1 real-time PCR test. Which risk factors are most likely involved in this infection? - Young horses returning from long distance transport - Young female horses during summertime - Young female ponies following return of a show - Tall, aged female horses following return of a horse competition

Answer 91

- Tall, aged female horses following return of a horse competition

Question 92

A lesion of cranial nerve IV will cause which of the following: - Ventrolateral strabismus because the oculomotor nerve innervates the ventral oblique muscle - Dorsomedial strabismus because the trochlear nerve innervates the dorsal oblique muscle - Medial strabismus because the trochlear nerve innervates the lateral rectus muscle - Dorsolateral strabismus because the abducens nerve innervates the lateral rectus muscle

Answer 92

- Dorsomedial strabismus because the trochlear nerve innervates the dorsal oblique muscle

Question 93

Which of the following tests is most beneficial in determining whether a neurologic horse is demonstrating signs of paresis? - Blindfolding - Tail pull - Any test is useful because all horses with neurologic disease have component of weakness - Obstacle course

Answer 93

- Tail pull

Question 94

The afferent and efferent pathways of the menace response rate? - Afferent = the oculomotor nerve and efferent = the ophthalmic branch of nerve V - Afferent = the optic nerve/ efferent = the oculomotor nerve - Afferent = the optic nerve and efferent = the facial nerve

Answer 94

- Afferent = the optic nerve and efferent = the facial nerve

Question 95

A case is presented with the hindlimb deficits present at all times. The neurological examination reveals a stabbing hindlimb gait exaggerated by backing the hrse and elevating the head. Exam on the tight circle reveals pivoting on the hindlimbs. What is your neuroanatomical diagnosis? - Cervical (C2-T2) - Central - Thoracolumbar (T2-S2) - Sacral/coccygeal

Answer 95

- Thoracolumbar (T2-S2)

Question 96

Radiograph of incomplete carpal ossification of carpal bones.

Answer 96

?

Question 97

Radiograph of fetlock asking for what was going on - fuzzy bone appearance around joint.

Answer 97

?

Question 98

Decreased masseter muscle mass is associated with which cranial nerve?

Answer 98

- Cranial nerve V

Question 99

What are some clinical signs of cerebellar ataxia?

Answer 99

- Intention tremors & wide based stance

Question 100

What is a pathognomic sign for a clostridium tetani infection? - SC gas formation - Flaccid paralysis - 3rd eyelid prolapse - Hypothermia

Answer 100

- 3rd eyelid prolapse

Question 101

A 5 week old Appaloosa foal presents with dysphagia, a stilted gait & muscle tremors. The tail & tongue tone are weak. The vital signs & blood analyses (CBC & serum chemistry) are normal. Endoscopic evaluation of the pharanx shows pharyngeal paresis but reveals no mechanical obstruction. What is the most likely diagnosis & how should the foal be treated?

Answer 101

The foal has the toxico-infectious form of botulism & treatment should include polyvalent antiserum (& metronidazole)

Question 102

Following initial examination of a case with fever of unknown origin (FUO) & additional haematology & biochemistry within normal limits, what is the best choice for next diagnostic procedures? - Transrectal examination & ultrasound - Endoscopy & ultrasound - Ultrasound & radiology - Radiology & urinalysis

Answer 102

- Ultrasound & radiology

Question 103

On a latermedial radiograph, an increase in the exact vertical distance between the coronary band & the extensor process of the third phalanx (P3) indicates: - Negative palmar angle - Sinking of P3 - Reduced sole depth - Rotation of P3

Answer 103

- Rotation of P3

Question 104

A 2 year old Warmblood colt is presented with acute onset of neurologic deficits: reluctant to back up, stumbling & knuckling while walking on a straight line, & circumduction of the hind limbs when circling to both directions. All four limbs are affected but the hind limbs seem more severely affected. What is the most likely neuroanatomic localisation? - Sacral (S1-S3) - Cervical (C1-C7) - Brainstem - Cervico-thoracic (C7-T1)

Answer 104

- Cervical (C1-C7)

Question 105

Which cranial nerve is likely affected if the horse has a head tilt, horizontal nystagmus & is circling? - Cranial nerve XII - Cranial nerve V - Cranial nerve II - Cranial nerve VIII

Answer 105

- Cranial nerve VIII Vestibular nerve

Question 106

Which of the following options include signs of lower motor neuron deficits? - Muscle tremors, intention tremors, muscle atrophy - Paresis, hyporeflexia, decreased muscle tone, muscle atrophy - Spasticity, hyperreflexia, normal to increased muscle tone, muscle atrophy - Decreased muscle tone, late onset atrophy, spasticity

Answer 106

- Paresis, hyporeflexia, decreased muscle tone, muscle atrophy

Question 107

Which of the following dietary management protocols are recommended for a horse suffering from equine metabolic syndrome? - Soak hay prior to feeding & limit non-structural carbohydrates at 10% of daily intake - Grass hay & no more than 50% of the day for grazing fresh grass in pasture - Oaten hay & recommend a grazing muzzle during pasture turn-out - Oaten hay & carbohydrates at 15-20% of daily intake

Answer 107

- Soak hay prior to feeding & limit non-structural carbohydrates at 10% of daily intake

Question 108

After a 1500m race, a horse presents with signs of behavioural changes, irritation & random kicking. What is the best initial treatment? - IV fluid therapy & sedation - IV fluid therapy & non-steroidal anti-inflammatory drugs (NSAIDs) - Non-steroidal anti-inflammatory drugs (NSAIDs) & cooling - Sedation & cooling

Answer 108

- Sedation & cooling

Question 109

Laminitis caused by endocrinopathic or metabolic dysfunction is associated with which of the following pathophysiological processes? - Triglyceride dysregulation - Hypercortisolaemia - Insulin dysregulation - Hyperglycaemia

Answer 109

- Insulin dysregulation

Question 110

Which form of ataxia is related to a horse that demonstrates ataxia without intention tremor or head tilt? - Vestibular - Spinal - Cerebellar - Trigeminal

Answer 110

- Spinal

Question 111

Please indicate the correct statement about management of septic arthritis. - Arthroscopic lavage of the joint increases the chances for cull recovery by 80% - Prolonged systemic antimicrobial therapy can control the infection - Regional limb perfusion with antimicrobials is inexpensive & can easily be performed on a standing horse - Joint lavage is essential but requires general anaesthesia

Answer 111

- Regional limb perfusion with antimicrobials is inexpensive & can easily be performed on a standing horse

Question 112

Please indicate the correct statement regarding angular limb deformities (ALD) in foals: - Growth retardation techniques would occur on the short (concave) side of the bone & would not overcorrect - ALD of the fetlock can be treated conservatively within the first 3 months of age - Carpal / tarsal valgus & fetlock varus are most common - Conservative therapy would include forced exercise of the foal

Answer 112

- Carpal / tarsal valgus & fetlock varus are most common

Question 113

Please indicate the most distal nerve block that would likely anaesthetise the whole foot. - Low 4-point block (palmar nerves & palmar metacarpal nerves in the distal half of the canon) - Palmar digital nerve blocked at the level of the proximal sesamoid bones (abaxial nerve block) - Palmar digital (PD) nerve block at the level of the pastern - High 4-point block (palmar nerves & palmar metacarpal nerves close to the carpometacarpal joint)

Answer 113

- Palmar digital nerve blocked at the level of the proximal sesamoid bones (abaxial nerve block)

Question 114

After an intense training session, a thoroughbred colt presented with mild lameness & swelling over the palmar mid-metacarpal soft tissue area of his left foreleg. On palpation, the affected mid-metacarpal area is warm & mildly painful. Which of the following is true about this case? - Immediate cold therapy, support bandage & anti-inflammatory therapy are indicated - This is likely a lesion within the digital flexor tendon sheath & the horse should recover in 2 weeks - Desmotomy of the palmar annular ligament is indicated & the colt should be back in training in 4 months - This is likely desmitis of the suspensory ligament (M. interosseous) & may be treated with stem cell injections

Answer 114

- Immediate cold therapy, support bandage & anti-inflammatory therapy are indicated

Question 115

A 1 year old horse suddenly started exhibiting right hind lameness & right hock effusion. Radiographic evaluation revealed a loose osteochondral fragment in the tarsocrural (i.e. tibiotarsal) joint. Please indicate the most likely disease & the best therapeutic approach for this horse. - Septic arthritis, antibiotic therapy plus immobilisation - Osteochondrosis, anti-inflammatories plus stall rest - Septic arthritis, antibiotics & arthroscopic surgery - Osteochondrosis, arthroscopic surgery

Answer 115

- Osteochondrosis, arthroscopic surgery

Question 116

Please indicate the correct statement about the morphology & physiology of synovial joints. - In mature horses, the articular cartilage is supplied by vessels & nerves which explains why arhtirits causes so much pain - Synovial fluid is produced mostly by the chondrocytes - The subchondral bone provides physical support & nutrition to the deep layers of the articular cartilage - The only function of the synovial fluid is lubrication of articular cartilages

Answer 116

- The subchondral bone provides physical support & nutrition to the deep layers of the articular cartilage

Question 117

What are some possible complications of bone healing?

Answer 117

- Recovery accident - Surgical site infection - Catastrophic failure of construct / bones - Supporting limb laminitis - Cast complications - Angular limb deformity of the opposite limb - Flexural limb deformity - Osteoarthritis

Question 118

Define Osteochondrosis & the 2 subtypes that fall under it.

Answer 118

Osteochondrosis (OC) = defective endochondral ossification of the epiphysis leading to cartilaginous and/or osteochondral fragmentation. Failure of the hypertrophic zone to undergo mineralisation & progression to bone formation. Osteochondritis dissecans (OCD) = Abnormal cartilage break-off. Fragmentation of articular cartilage and/or subchondral bone due to defective endochondral ossification Subchondral bone cyst / subchondral cystic lesion (SCL) = Abnormal cartilage collapse. Defective endochondral ossification of the epiphysis leading to cyst in the subchondral bone

Question 119

Compare & contrast Osteochondrosis Dissecans (OCD) & Subchondral Cystic Lesions (SCL).

Answer 119

Definition: - OCD = abnormal cartilage break off with variably detached flaps of cartilage. Typically affects non-weight bearing areas. - SCL = abnormal cartilage collapse. Appears like areas of resorption (radiolucency). Less common than OCD & typically affects weight-bearing areas. Affects: - OCD = affects young animals and/or recent increase in physical activity - SCL = affects animals of variable age with no particular recent increase in physical activity Aetiology: - Genetics - Mechanical forces - Nutrition Clinical signs: - OCD = effusion. Often no clinical signs (incidental finding on survey xrays). No or mild-moderate lameness. - SCL = no effusion. Lameness scale from 0 to 5/5. Most commonly affects medial femoral condyle. Treatment: - OCD = limited physical activity. Only time & possible vascular repair of site to that zone will lead to repair. Diet correction (reduced CH, CU, Zn). Systemic NSAIDs. Other meds: hyaluronic acid, chondroitin sulphate, pentosane sulphate. Surgical treatment = arthroscopic debridement. - SCL = rest. Systemic NSAIDs. Intra-articular meds: corticosteroids, HA, chondroitin sulphate, pentosane sulphate. Arthroscopic debridement +/- filling. Stem cells or platet rich plasma. Prognosis: - OCD generally has better prognosis than SCL (not having full weight bearing surface). - Depends on type, location, unilateral or bilateral, severity of lesion Prevention: - Genetic selection - Nutrition - Exercise / stabling management - Early management of conformation defects - Trimming (provide good trimming at early age in foals)

Question 120

Discuss Degenerative Joint Disease (DJD).

Answer 120

Significance / importance: - Lameness = most common equine health issue accounting for 8% of horse deaths in US 2006 & economic losses up to >1 billion / year - Joint disease is the most common cause of impaired mobility & loss of quality of life in horses, dogs & humans Pathogenesis: - Excessive load damaging cartilage and/or subchondral bone > joint instability, wear & tear, trauma - Normal load on weak (abnormal) or weakened cartilage and/or subchondral bone > congenital (OCD, SCL, conformation), acquired (chronic inflammation, iatrogenic, infection) Posisble consequences of DJD: - Structural changes - Pain - Loss of function Diagnosis: - Signalment - age, breed, use / discipline - History - poor performance / behaviour, lameness - C/S - poor performance / lameness, joint enlargement / remodelling, reduced range of motion, painful response to flexion, muscle atrophy, response to diagnostic anaesthesia - Imaging - radiography (new bone formation, subchondrla bone sclerosis, radiolucency in the subchondral bone, narrowing of the joint space, periarticular thickening), CT & MRI

Question 121

Discuss treatment / management of Degenerative Joint Disease (DJD).

Answer 121

Main goals of treatment: - Reduce pain (lameness) - Reduce progression of joint degeneration NSAIDs: - Mainstay for treatment of joint disease - Inhibit arachidonic acid cascade & production of prostaglandins & thromboxanes - Renal & GI side effects limit long term use - Recent research: NSAIDs may have long term negative effect on cartilage metabolism Steroidal anti-inflammatory drugs (glucocorticoids): - Most potent class of drugs for DJD - Act on steroid receptors in cell nucleus - Inhibit: movement of inflammatory cells, lysosomal enzyme release - Controversial view of corticosteroids - controversy over risk to benefit ratio Other injectable drugs commonly used: - HA (hyaluronic acid) - PSGAG - Pentosan polysulfate - Polyacrylamide hydrogel - Regenerative therapy Oral supplements: - Neutraceuticals - not approves as drugs - Many products but little to no information on safety & efficacy Modification of exercise: - Training & competition scheme Corrective trimming / shoeing: - Improve rolling - Improve stability - Improve balance - Increase shock absorbance Physical therapy: - Cold application - applied during inflammatory phase, significantly decreases soft-tissue perfusion - Limb immobilisation - prevent further injury, support unstable joint - Controlled mobilisation - passive flexion, swimming & water treadmills - Magnetic rugs - boots - Therapeutic ultrasound - Class IV therapeutic cold lasers - Shock wave therapy Stimulated Endogenous Repair (SER): - Bone marrow has good supply of stem cells & GF for cartilage repair Articular Grafting: - Tissues grafted into cartilage defects Arthrodesis: - Assisted fusion indicated when joint destruction is beyond limits of other treatment - Methods: internal fixation, chemical, laser Osteotomy (joint replacement): - Indicated when: reparative surgery has failed, unresponsive to medical treatment, end stage OA - *Not used in equine due to high morbidity (loosening), prolonged non-weight-bearing, cost, etc.

Question 122

Discuss fractures of the dorsal spinous process (DSP) of T2-T9, the aetiology, clinical signs & treatment.

Answer 122

Aetiology: - Most fractures associated with falls

Question 123

Discuss Impinging Dorsal Spinous Processes (IDSP) otherwise known as Kissing Spine.

Answer 123

- "Kissing Spine" or "Overriding DDSP" (ODSP) = most common cause of T-L pain - Mid-thoracic (T12-T18 saddle region) most common - Lumbar less common (but also underdiagnosed due to difficulty penetrating muscle mass) Aetiology: - Multifactorial - Differences in conformation - Lordotic conformation - Type & amount of work - Jumping - Thoroughbreds & their crosses Clinical signs: - Chronic back pain despite therapy - Back stiffness - Lack of impulsion - Resentment of spinal flexion or extension on manipulation Diagnosis: - Palpation - Lameness exam - Local anaesthesia - Radiography - Ultrasound - Nuclear scintigraphy Management: - Conservative - NSAIDs e.g. Gabapentin - Specialised exercise regime / tack change - Physiotheraphy - rehab & exercise restriction very important - Local injection with corticosteroids - Shockwave - Surgical - cranial wedge ostectomy, interspinous ligament desmotomy

Question 124

Discuss synovial sepsis.

Answer 124

Aetiology: - Penetrating traumatic injury - Iatrogenic introduction by surgical intervention or intrasynovial injection - Haematogenous spread - foals Most common agents: - Staphylococcus (especially S.Aureus) - Streptococcus - E.coli, Klebsiella, Salmonella Pathophysiology: - Infectious organism causes acute inflammation > blood synovial membrane is disrupted > influx of neutrophils > proteolytic enzymes, proinflammatory mediators (IL1, TNFalpha, PG) are released > increased synovial fluid in the joint Diagnosis: - Radiography (+ contrast arthro / tenography) - Ultrasonography - MRI - Synovial fluid collection by arthrocentesis - culture of synovial fluid is gold standard Treatment: - Synovial sepsis is a serious, potentially life-threatening & performance-limiting condition - Prompt aggressive treatment is required - Ideally should have C & S results however need to start treatment asap! - Broad spectrum AB's - procaine penicillin (gram positives), gentamicin (gram negatives) - Phenylbutazone (bute) - Joint lavage - if you put a needle in & get orance (septic) fluid then joint lavage is the most important treatment step (don't just treat it systemically with AB's) - Needle lavage - advantages = can be performed in field standing or under GA, cheaper & doesn't require referral hospital. Disadvantages = won't flush fibrin out which is what creates bacterial biofilm & cannot assess articular surface for cartilage damage - Arthroscopy - advantages = thorough inspection of joint, can manually remove fibrin. Disadvantages = must be done under GA, is costly

Question 125

Discuss osteitis / osteomyelitis.

Answer 125

Osteomyelitis = inflammation of bone usually due to infection Pain management: - NSAIDs - phenylbutazone - Opioids - Local or epidural anaesthesia - Immobilisation (bandage / cast) - CRI's: ketamine, lidocaine, butorphanol - Prevention of support limb laminitis Monitoring: - Severity of lameness - Clinical appearance of synovial structure / bone - Other vital signs (HR, RR, temp) - Repeated fluid analysis - WBC, TP - Repeat imaging Survival to discharge: - Prognosis guarded to start - Only 50-80% of horses return to their previous level of function Prognosis: - Decreases with delayed treatment - Decreases if multiple synovial structures involved - Poor prognosis reported for solar foot penetrations involving synovial structures & calcaneal bursa sepsis

Question 126

List the different cranial nerves & their functions.

Answer 126

I = Olfactory: - Sensory > smell - Assessment is difficult (recognition of treats whilst blindfolded) II = Optic: - Sensory > vision - Assessment - menace response (wave hand in karate chop near eye), note normal foals do not have a menace response until 1-2 weeks old III = Oculomotor: - Motor > medial & ventral ocular muscles (muscles of the upper eyelid, parasympathetic control of pupil constriction) - Assessment - position of globe, pupillary size (pupillary light reflex), (ventro-lateral) strabismus (eye points in different directions = can indicate oculomotor damage) IV = Trochlear: - Dorsomedial strabismus V = Trigeminal: - Motor > muscles of mastication (masseter & temporalis) - Sensory > most of face - Assessment - stimulate facial skin using your fingers VI = Abducens: - Motor - Medial strabismus & inability to retract globe VII = Facial: - Probably the most common cranial nerve to see neurological disease with - Motor > muscles of facial expression > droopy ear / eyelid, muzzle deviation, dry eye VIII = Vestibulocochlear: - Cochlear (auditory) > hearing - Vestibular division > balance - Vestibular disease signs: spontaneous nystagmus (usually horizontal), peripheral = head tilt & drifting / circling towards lesion IX = Glossopharyngeal: - Control of the pharynx & larynx X = Vagus: - Control of the pharynx & larynx XI = Accessory: - Motor > trapezius & cranial part of sternocephalicus muscle - Evaluation - cervicofacial response XII = Hypoglossal: - Motor > muscle of the tongue - Unilateral disease = atrophy of tongue muscles, weak retraction of tongue back into mouth - Bilateral disease = reduced apprehension & swallowing, tongue protrudes

Question 127

List the grading system for gait deficits.

Answer 127

Grade 0 = normal strength & coordination Grade 1 = normal / barely detectable at walk in straight line; worsened by manipulations Grade 2 = deficit easily detected at normal gait, exaggerated by manipulations Grade 3 = deficit very prominent at walk, tendence to buckle or fall with manipulation Grade 4 = stumbling, tripping, falling spontaneously Grade 5 = recumbent

Question 128

Compare Lower Motor Neuron (LMN) signs with Upper Motor Neuron (UMN) signs.

Answer 128

LMN: - Motor function = paresis to paralysis, weakness, flaccidity - Reflexes = hyporeflexia, areflexia - Muscle tone = decreased - Fasciculations (twitching) = present UMN: - Motor function = paresis to paralysis, loss of voluntary movements or spasticity - Reflexes = normal to hyperreflexia - Muscle tone = normal to increased - Fasciculations (twitching) = absent

Question 129

Discuss the main clinical signs associated with each anatomical location: cerebrum, brain stem, vestibular system, cerebellum, spinal cord UMN, spinal cord LMN

Answer 129

Cerebrum: - Altered mentation, seizures, blindness Brainstem: - Multiple cranial nerve deficits, ataxia, paresis Vestibular system: - Head tilt, nystagmus, ataxia, postural deficits Cerebellum: - Intention tremors, wide-based stance, hypermetric, loss of menace response. Strength is maintained (i.e. no paresis) Spinal cord UMN: - Ataxia, dysmetria, spasticity, paresis Spinal cord LMN: - Flaccid paresis, ataxia, muscle atrophy

Question 130

Neuroanatomical localisation if there is a gait abnormality.

Answer 130

All 4 limbs, HL worse than FL = C1-C7 All 4 limbs, FL worse than HL = C6-T2 FL normal, HL abnormal = T-L region Tail / bladder paralysis, perineal hypalgesia = Sacral

Question 131

Discuss Cervical Vertebral Stenosis (Wobbler's Syndrome).

Answer 131

- Compression of the cord causes gait abnormalities - Affects any age or breed but particularly: young & fast growing, male thoroughbreds overrepresented - Typical history - was fine until they stumbled which exacerbated a lesion in the spinal cord Clinical signs: - Ataxia, weakness, dysmetria, spasticity (hindlimbs > forelimbs because lesions are typically in C1-C7), usually symmetrical, often sudden onset - Occasionally neck pain on grazing Diagnosis: - Sagittal ratios - divide width of the spinal canal by the width of the corresponding widest point of the cranial aspect of the vertebral body - Myelography = most definitive ante-mortem diagnosis of Wobbler's. Inject radiographic contrast media into intrathecal space & then take radiographs Lesions seen in Wobblers: - Osteochondrosis of vertebral facets - Malalignment of vertebra - Caudal epiphyseal flare - Stenosis of the vertebral canal - Joint capsule out-pouching Treatment - surgery: - Modified Cloward's technique - essentially we're fusing the neck (the horse will have a stiff neck)

Question 132

Summary of neurolocalisation.

Answer 132

- If you have (multiple) cranial nerves involved & change in mentation = brain stem lesion - If you have abnormal behaviour (seizures, blindness) & change in mentation = cerebral lesion - If you have a horse with a head tilt & circling towards lesion & nystagmus = vestibular disease - If you have intention tremors = cerebellar disease - If you have proprioceptive deficits (stumbling, knuckling) & all 4 limbs affected but worse in the hindlimbs = lesions within C1-C7 - If you have proprioceptive deficits (stumbling, knuckling) & all 4 limbs affected but worse in the forelimbs = lesions within C7-T2 - If you have changes in sensation of the peri-anal area, abnormal tail tone & dribbling of urine = sacral lesion - If we’re pulling the tail & the horse is weakening = likely lower motor neuron deficit - If we’re pulling the tail & the horse & the horse isn’t weakening = the horse doesn’t have lower motor neuron deficits - Muscle fasciculations = more likely to be lower motor neuron

Question 133

Discuss Cauda Equina syndrome.

Answer 133

- Commonly occurs in horses that were secured with ropes on the tail under GA - Loss of anal & tail tone - Faecal impaction - Dilated urinary bladder - Urine dribbling – check perineum for urine scalding

Question 134

Discuss Equine Herpes Virus Myelocencephalopathy (EHM).

Answer 134

- Rare phenomenon - Contagious disease - Presents as an outbreak (10-50%) Presentation: - Acute onset +/- fever - Asymmetrical ataxia & weakness - Frequently: dysuria Progresses to... - Bladder paresis - Faecal retention - Tail & anal-tone deficits - Perineal hypalgesia - Dog-sitting Risk factors: - Outbreaks with fevers & (mild) respiratory disease - Tall breeds (less in ponies) - Older horses (>3-20y) - Fall-winter-spring - Typically following return of horse from event & transport - Severe EHM is more common in aged female horses Epidemiology: - Infection of endothelial cells > vasculitis - By aerosolised nasal secretions (coughing) - By aborted foetus Diagnosis: - Body temp 2x daily - increased by 1-1.5 degrees - Nasal swab, PCR - negative result - Blood sample after 3 days PCR - positive result - Blood sample serology 2x - 4x titer ELISA or SN History: - Acute onset neurological signs - History of fever - Multiple horses involved Biosecurity: - Quarantine case ideally for 28 days (min 14 days + testing all horses), close the farm - Only partly protection of horses by vaccination Treatment: - Supportive - Bladder catheter for 3 days - NSAIDs: flunixin meglumine +/- aspirin, pre-EHM phase - Antiviral treatment: acyclovir & valacyclovir Prognosis: - Good > months

Question 135

Discuss Ross River Virus.

Answer 135

- An arthropod (insect) borne arbovirus - Problems in horses & humans, dogs, cats - Carrier & reservoir: wallabies & kangaroos (& birds, humans) - Transmission: by biting female mosquitoes Risk factors: - In high endemic areas with year-round mosquitoes (80% seropositive in QLD, 50% in SA) - Summer months - Near fresh water & rainfall - Annual recurrence of clinical signs Clinical signs: - Poor performance, lethargy & muscle stiffness - Horses develop transient viraemia – minimally pathogenic - Minimal or no signs - Initially 4-5 days fever > intermittent fever - Reluctant to move: polyarthritis, swelling joint (synovial effusion) & oedema lower limbs - Lameness, limb soreness - Chronic fatigue-like syndrome: ‘tying up during exercise’ - No neurological signs Diagnosis: - Virus isolation: cell culture / PCR - Serology testing: Curren test – virus neutralisation test (VNT) – normal titre <20

Question 136

Discuss Japanese Encephalitis Virus.

Answer 136

- Flavi virus - 1935: first isolated from fatal human encephalitis in Japan - In piggeries across several states in Aus in 2022 - Spread of flavi viruses depends on: vectors - Culex mosquito activity depends on environmental temperature & humidity (rainfall) Clinical signs: In horses & humans are sub-clinical... - Pyrexia, icterus - Lethargy, anorexia - Neurological signs: ataxia, difficulty swallowing, impaired vision, over-excited (rarely) - Children: death may occur Pathogenesis: - Zoonosis - Encephalitis in 0.04% cases (mainly children) - Currently 3 billion people in endemic areas - Australia since 2021: 45 human cases including 7 deaths Diagnosis - difficult: - Clinical signs - Serology - ELISA & SN test - RT-PCR of tissue, serum, CSF (high false positive & negative) - Histopathology - non-suppurative encephalitis, immunohistochemistry

Question 137

Discuss Kunjin Virus.

Answer 137

- A Flavivirus Epidemiology: - Hosts - waterbirds? - Arthropod borne - mosquito bite History: - Heavy rainfall, no fever, rapid progression (hours) over few days Clinical signs: - Depressed, drooping lips, dysphagia, blindness (more in young horses), hyperasthesia, muscle fasciculations & tremors especially head & neck, ataxia, circling, hypermetria - Commonly LMN weak, dragging toes front / high stepping behind Treatment & prognosis: - With 'stall rest' & wait & see clinical signs will gradually improve with time

Question 138

Compare the key differences between Kunjin virus & Hendra virus.

Answer 138

Kunjin Virus: - Normal temperature - Slow progression & less severe - Exposure to mosquitoes close to water Hendra Virus: - Higher fever - Rapid progression & always fatal - Exposure to bats

Question 139

Discuss Hendra Virus.

Answer 139

- Mainly in NSW & QLD - Henipavirus genus, class of Paramyxoviridae family - Zoonotic disease Transmission: - From bats to horses: food contaminated by birth fluids, saliva or urine - From horses to people Clinical signs: - Initially vague - fever, increased HR, discomfort / weight shifting between legs (colic signs) - Progressing to rapid deterioration with respiratory & neurological signs - Resp signs - difficulty breathing, nasal discharge, weakness, loss of coordination,collapse - Neurological signs - wobbly gait, altered consciousness, head tilt, muscle twitching, urinary incontinence Diagnosis: - PCR, ELISA, VNT - Blood - Nasal swabs - Oral (rectal) swabs Treatment & prevention: - No specific treatment available - Reducing the risk - protect food & water sources from contamination by flying foxes - Vaccination - immunity develops 21 days after 2nd dose, booster every 12 months

Question 140

Differentiate between central & peripheral neuropathy.

Answer 140

Central: - Abnormal mentation - Ataxia (incoordination, loss of proprioception) - Dysmetria (hypometria, stiffness, hypermetria, exaggerated flexion) - Paresis / paralysis (loss of strength, weakness) Peripheral: - Normal mentation - No ataxia or dysmetria - Paresis / paralysis - Loss of strength / weakness with muscle fasciculations - Muscle atrophy

Question 141

Discuss Temporohyoid Osteoarthropathy (THO).

Answer 141

- = stylohyoid bone fused with the petrous temporal bone which results in vestibular disease & facial nerve paralysis due to: o Osseous proliferation push upon cranial nerves VII & VIII o OR petrous temporal bone fracture Acute clinical signs: - Vestibular disease - Facial nerve paralysis - Pain associated with palpation of the ear Chronic signs: - Head shaking & keratitis sicca - Enlargement of hyoid diagnosed at GP scopy & CT

Question 142

Discuss bilateral plant-associated Stringhalt.

Answer 142

- Mononeuropathies, ‘Equine reflex hypertonia’ - Distal axonopathy in peripheral nerve > affecting large myelinated axons - Affecting peroneal nerve: an abnormal input of alpha efferent neurons resulting in abnormal firing of long distal extensor muscle Aetiology & pathophysiology: - Idiopathic (classic) stringhalt: unilateral & progressive - Australian stringhalt: bilateral plant-assoc. & may recover Clinical signs: - Usually symmetric involvement of pelvic limbs - Involuntary hyperflexion of: o 1 or 2 hock joints (commonly) or 4 limbs when moving o Grade I-V (‘bunny-hopping’) Diagnosis: - EMG is diagnostic (abn spontaneous activity) - Muscle & nerve biopsy* Treatment: - Recovery in weeks > months - Remove from pasture: gradual improvement over 6-8 months (majority of cases) - Anti-inflammatories & high dose Vitamin E (6000 IU/d PO)* - Phenytoin - Botox - Myotenectomy of lat dig ext tendon

Question 143

Discuss Cauda Equina Syndrome / Polyneuritis Equi.

Answer 143

- Definition: loss of function due to damage of the most caudal spinal nerves (afferent or efferent) >> S1 Sacrococcygeal lesion - clinical signs: - No ataxia (!) - Flaccid tail - Lower motor neuron bladder – overflow bladder - Parapysis rectum: coprostasis - Male: penis prolapse - Hypoesthesia area perineal zone + hypersensitive area Ddx: - Trauma – most commonly - Neoplasia - EPM - EHV-1 - Rabies Treatment: - Corticosteroids/ NSAIDs, Vit E - Diet >> attempt to soften stools - Daily rectal evacuations, monitoring micturition, stall rest some hand walking

Question 144

Discuss "Headshaking" - Peripheral mononeuropathy > abnormal behaviour.

Answer 144

Clinical signs: - Onset exercise, trot vertical, horizontal, both & agitation - ± Sneezing, rubbing nose - 60% seasonal, ± 9y, > male - Is this a response to naso-facial irritation or pain? Role of trigeminal nerve / neuropathy? Provocation testing: - Nose net: 30% + - Eye mask: photic headshaker (EVJ 1995) - Management during riding: without bit, not during sunny weather, stabling,…

Question 145

Discuss Tetanus.

Answer 145

Aetiology: - Clostridium tetani, anaerobic spore-forming Gram+ bacillus - Ubiquitous in soil & GI tract - Spores are resistant to high temp / disinfectants - Horse is sensitive Clinical signs: - “Inhibits the inhibitor” - Extreme muscle rigidity (extensors) - “Saw-horse” stance: hypertonia & muscle spasm - Normal conscious proprioception - CN deficits leading to: o Risus sardonicus o Trismus (lock-jaw) o Protrusion of 3rd eyelid o Enophthalmos (sunken eyes) o Laryngeal spasm o Dysphagia Pathogenesis: - Tetanolysin: necrosis in local tissue - Tetanospasmin: o Toxin circulates to peripheral nerve terminals in spinal cord (A) & brain(stem): o To irreversibly bind inhibitory interneurons (D) o To inhibit inhibitory neurotransmitters (B): GABA & glycine - > Decreased suppression of skeletal (& smooth) muscle activity > hypertonia & muscle spasm

Question 146

Discuss Botulism.

Answer 146

Pathogenesis: - Clostridium botulinum toxins: o In horses: mostly toxins A, B, C & D o Toxins absorbed from GI tract o Haematogenously spread to peripheral nerve endings at peripheral neuro-muscular junctions o Toxin blocks release of neurotransmitter Acetylcholine o >Bilateral symmetrical generalized flaccid paralysis (= weakness) Clinical signs: - Cranial nerve neuropathy: dysphagia, mydriasis - Gait & posture abnormalities: muscle tremor & weakness - Autonomic nervous system abnormality: ileus, bladder atony Diagnosis: - Isolation of C. botulinum = supportive of diagnosis - Diagnosis by ruling out other possibilities (clinical diagnosis) - Additional diagnostic tests: o Tongue stress test o Grain test – offer 0.25kg of sweet feed in flat tub; normal consumption <2 min o Spores in faeces (rare) o Toxin rarely isolated o Mouse bioassay (difficult) Prognosis & therapy: - Remove source of toxin - Hyperimmune plasma ($$$) - Supportive care until sufficient functional synapses are back (10 - 20 days) - REST (& parenteral nutrition) - Antimicrobials? – generally not o Maybe prevent 2nd infections (aspiration pneumonia, decubital ulcers) - Prognosis is poor to good: with plasma treatment & IC: 50-90%

Question 147

What are the most common signs of peripheral neural diseases?

Answer 147

Typical clinical signs of peripheral neural disease are: o Paresis/ paralysis, loss of strength, weakness with: o Muscle fasciculation o Muscle atrophy!! No ataxia or dysmetria!