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Flashcards in Medicine Deck (144):
1

List the 4 syndromes of visceral pain.

1. Distension
2. Ischaemia
3. Mesenteric tension
4. Increased intraluminal pressure in hollow viscera

2

What are the common causes of chest pain?

Usually parietal pleural.
-pleuritis
-pleuropneumonia
-pneumonia
-lung abscess

3

What are the possible causes of headshaking?

1. Trigeminal neuralgia
2. Photophobia

4

Define hyperthermia.

Significant increase in body temperature where the core body temperature set point is unaltered.

5

Define fever.

Significant increase in temperature where temperature set point is elevated.

6

List some causes of hypothermia.

1. Accidental eg. cold damp environment, surgery
2. Pathological eg. sepsis, shock, intracranial disease, hypothyroidism

7

Describe possible treatment options for a headshaking horse.

1. Trigeminal neurectomy (?)
2. Caudal compression of infraorbital nerve
3. Avoidance of stimuli eg. tinted contact lenses, face masks/hoods/nets
4. Cyproheptadine +/- carbamazine (together may have short effect and cause drowsiness)
5. Permanent tracheostomy- avoids stimulating airflow in nasal cavity

8

What empirical antibiotics should be used to treat neonatal pneumonia?

Cephalosporin

9

What are the potential sequelae to fractured ribs in the foal?

Haemothorax
Pneumothorax
Lacerated lung/pericardium/myocardium/diaphragm

10

List the differentials for neonatal respiratory disease.

Pneumonia
Fractured ribs
Aspirated meconium
Prepartum EHV-1 infection
Inadequate lung maturation

11

Outline the pathology and clinical signs of Rhodococcus equi infection in the growing foal.

Multifocal pulmonary abscessation +/- abscessation in other organs e.g. GIT.
Clinical signs:
-debility
-ill thrift
-progressive dyspnoea
-immune-mediated polysynovitis

12

How might you treat Rhodococcus equi infection in the foal?

A/bs: macrolide (erythromycin) + rifampin

13

How can you prevent Rhodococcus equi infection in a group of growing foals?

1. Improve husbandry e.g. reduce stocking density, prevent dusty areas, rotate paddocks
2. Administer appropriate prophylactic antibiotics
3. Administer specific hyperimmune serum

14

List the clinical signs of strangles.

Dysphagia
Bilateral purulent nasal discharge
Lymphadenopathy (submandib/submax/pharyngeal)
Extended neck
Dyspnoea

15

Define 'bastard strangles'.

Abscessation in other tissues besides usual LNs- including mediastinal + mesenteric LNs, joints. Dramatic weight loss and pyrexia occurs.

16

List the potential sequelae following a strangles infection.

Bastard strangles
Purpura haemorrhagica
Guttural pouch emphysema

17

What is the aetiological agent of strangles?

Streptococcus equi var equi

18

What disease does EHV-1 cause?

Reproductive disease (abortion) and encephalomyelopathy

19

What disease does EHV-2 cause?

Respiratory disease

20

What causes recurrent airway obstruction (RAO)?

Airway inflammatory response to organic dust particles (endotoxins, moulds, particulates) inhaled from poorly conserved hay/straw

21

List the clinical signs of recurrent airway obstruction (RAO).

Bilateral mucopurulent nasal discharge
Coughing (!!!)
Heave line
Audible wheezes/crackles

22

How is recurrent airway obstruction (RAO) treated?

1. Turn out or house in dust-free enviro e.g. shavings/paper bedding, haylage/chopped dred alfalfa/cubed diet, ventilation
2. Bronchodilators e.g. atropine
3. Prednisolone
4. Maintain hydration

23

What causes summer pasture associated obstructive pulmonary disease (SPAOD)?

Affects pastured horses with NO access to hay/straw in the Spring-Autumn. May be hypersensitivity to inhaled polens or outdoor moulds?

24

Where does bleeding originate from in exercise-induced pulmonary haemorrhage (EIPH)?

Dorsocaudal lung

25

On bronchoscopy of a horse with EIPH, what might you expect to find post-exercise at:
i) 30 minutes
ii) few days
iii) week

iv) What would you find on BALF/tracheal aspirates after a few months?

i) Fresh blood in trachea
ii) Blood in large bronchi
iii) Haemosiderin tinged secretions
iv) Macrophages containing haemosiderin

26

List the clinical signs of pulmonary abscesses/pleuropneumonia.

Pyrexia
Anorexia
Ventral oedema
Pleural pain
Lethargy

27

What parasite causes lungworm infestation in horses?

Dictyocaulus arnfieldi

28

List the causes of poor performance in the athletic horse.

1. Musculoskeletal
2. Respiratory
3. Lack of fitness
4. Unrealistic expectations (of horse/rider)
5. Inappropriate training
6. Cardiovascular
7. Other e.g. medical, neuro

29

Describe the features of atrial fibrillation i) on auscultation and ii) on ECG.

i) irregular rhythm with LOUD 3rd heart sound and NO 4th heart sound, may be tachycardic if secondary to mitral regurgitation
ii) irregularly irregular rhythm with no p-waves and atrial fluttering- 'f-waves'

30

Describe the treatment options for atrial fibrillation.

DO NOT TREAT if: only diagnosed 2-3 days ago (may spontaneously resolve), no effect on exercise or if there is evidence of heart failure.

1. Quinidine sulphate via nasogastric tube every 2 hours (beware toxicity).
2. Electric defibrillation via direct shock under GA

31

Describe the ECG features of i) premature atrial beats, ii) premature ventricular contraction and iii) 3rd degree AV block.

i) abnormal p-wave shape, early p-wave and QRS complexes
ii) no p-wave with wide bizarre QRS complexes
iii) multiple p-waves with no QRS complexes

32

List the causes of pericardial effusion.

Idiopathic fibrinous/effusive pericarditis
Neoplasia
Traumatic H+
Septic disease

33

List the causes of cardiac murmurs.

Acquired valvular: mitral regurgitation, tricuspid regurgitation, aortic insufficiency
Congenital: ventricular septal defect

34

Which pathology produces a pansystolic murmur loudest over the 5th intercostal space?

Mitral regurgitation

35

Which pathology produces a soft grade 2-3 pansystolic murmur loudest on the RHS?

Tricuspid regurgitation

36

Which pathology produces a diastolic musical murmur loudest over the 5th LHS intercostal space?

Aortic insufficiency

37

Describe the aetiology of tricuspid regurgitation.

LV failure -> pulmonary hypertension -> RV overload

38

Describe the aetiology of aortic insufficiency.

Progressive thickening and fibrosis of valve leaflets in older (>10yo) horses.

39

List the potential causes of mitral regurgitation.

Ruptured chordae tendinae
Any condition causing dilation of valve annulus e.g. DCM, aortic insufficiency, VSD
Congenital malformation of valve
Infective endocarditis
Eccentric hypertrophy and increased blood volume
Degenerative thickening of the valve leaflets.

40

List the causes of icterus.

Regurgitation icterus: reduced excretion of bilirubin with liver of biliary tract disease

Haemolytic/prehepatic icterus: increased production of bilirubin with haemolytic anaemia

Hepatic icterus: reduced conjugation or hepatic uptake of bilirubin with liver disease

41

List the methods which can be used to determine the cause of icterus.

1. Relative amounts of conjugated vs. unconjugated bilirubin
e.g. >25% conjugated = heptaocellular disease, >30% conjugated = cholestasis
2. Liver-derived enzymes- to assess if assoc w/ liver damage
3. Bile acids- to assess if assoc w/ liver failure
4. PCV + RBCC- to assess if assoc w/ haemolysis

42

What is the likely cause of icterus with increased unconjugated bilirubin in the serum and reduced PCV?

Haemolysis

43

What is the likely cause of icterus with increased unconjugated bilirubin in the serum, normal PCV and liver enzymes?

Anorexia

44

What is the likely cause of icterus with increased unconjugated and conjugated bilirubin in the serum and rincreased liver enzymes and bile acids?

Liver disease

45

Which liver-derived enzymes are specific to hepatocytes?

GLDH (spec), AST

46

Which liver-derived enzymes are specific to the biliary tract?

GGT (spec), AP

47

What are the clinical signs of equine liver disease?

Icterus
Photosensitisation
Severe pruritus
Hepatic encephalopathy -> neuro signs e.g. dull vacant expression, yawning, ataxia, tremors, circling, head pressing, aggression
Bilateral laryngeal paralysis -> dyspnoea, stridor at rest
Petechiae
Coagulopathy

48

Describe how you would treat hepatic encephalopathy.

Sedate with low dose alpha-2 agonists
Correct metabolic, fluid and electrolyte abnormalities
Reduce GIT production/absorption of potential neurotoxins through laxative and oral neomycin/metronidazole
Lactulose- reduce intestinal neurotransmitter production/absorption

49

What would a negative response on the thoracolaryngeal reflex suggest?

Possibly recurrent laryngeal neuropathy

50

Describe where you would perform a CSF tap in horses.

1. Atlantooccipital (AO)
2. Lumbosacral
Always tap closest to the lesion!

51

What is the most common cause of equine brain disease in the UK?

Hepatic encephalopathy

52

What is the causative agent of leukoencephalomalacia?

Fusarium species mycotoxicosis from mouldy feed.

53

What is the cause of polyneuritis equii?

Chronic granulomatous inflammation of extradural nerve roots of many peripheral nerves.

54

What are the clinical signs of polyneuritis equii?

Cranial nerve deficits (VII/VIII first)- progressive

55

What is the cause of temperohyoid osteoarthropathy?

Proliferative osteopathy of unknown cayse of temporal and hyoid bone and temperohyoid joint. Tongue movement can fracture the temporal or stylohyoid bone which damages facial and vestibulocochlear nerves.

56

What are the clinical signs of temperohyoid osteoarthropathy?

Vestibular/facial nerve signs
Head shaking
Dysphagia

57

Which cranial nerves are most commonly affected by guttural pouch mycosis?

7, 8-sympathetic, 9, 10, 12

58

Describe the clinical signs of cerebellar ataxia.

Loss of subconcious proprioception ONLY (so will still replace legs in normal positions if moved abnormally)
Head movement
Hypermetria
Incoordination

59

Describe the clinical signs of vestibular ataxia.

Wide based stance (world is spinning!!)
Head tilit
Increased extensor tone on 1 side
Nystagmus (rare)

60

What are the most common causes of equine ataxia in the UK?

Spinal cord trauma
Cervical vertebral malformation

61

Define type 1 cervical vertebral malformation.

Large young horses with developmental narrowing of canal at C3-4.

62

Define type 2 cervical vertebral malformation.

Large older horses with arthritis of the caudal cervical vertebrae compressing the spinal cord.

63

How is cervical vertebral malformation treated?

On radiography: vertebral canal width should be >50% width of vertebral body.

64

What is the aetiological agent of equine herpes myeloencephalopathy?

Equine herpes virus (EHV-1)

65

Where is the reservoir for EHV-1 in latently affected horses?

Trigeminal nerve ganglia.

66

What are the clinical signs of equine herpes myeloencephalopathy?

Penis out if male
Cauda equine
Poor anal/tail tone
Pelvic > thoracic ataxia
Poor urinary function
Respiratory signs
CSF = xanthochromic (due to breakdown products)

67

How is equine herpes myeloencephalopathy treated?

Dexamethasone and oral antivirals

68

What is the causal agent of equine protozial myeloencephalitis?

Sarcocystitis neurona

69

What are the clinical signs of equine protozoal myeloencephalitis?

Atrophy of muscles of mastication

70

What are the causes of weight loss/failure to gain weight?

Mangement/physiology e.g. poor nutrition, increased metabolic demands- pregnancy, old age
Disease e.g. dysphagia, maldigestion, increased consumption v. loss

71

How would you treat a generalised case of weight loss?

Assess weight and set date for re-evaluation
Dietary change
Stop/start any long-term medications e.g. bute may cause colitis/protein loss
Anthelmintic therapy- larvicidal dfoses of anthelmintics even if apparently adequate worming regime

72

What 2 diagnostic tools are used to evaluate equine metabolic syndrome?

Fasting blood glucose and insulin: increased insulin = insulin resistance, increased gluc = severe insulin resistance/DM
Oral glucose tolerance test (OGTT): blood gluc should double within 2 hours of IV gluc admin then reduce to norm levels within 6 hours

73

How might you advise treating equine metabolic syndrome?

Control calorific intake e.g. feeds with low glycaemic index
Exercise
Medicate for obesity ????
Treat identifiable underlying cause

74

Define polyuria in the horse.

>50ml/kg/day

75

Define polydipsia in the horse.

>100ml/kg/day

76

What are the causes of PU/PD in the horse:

Psychogenic PD
Equine cushing's syndrome
Renal disease
Psychogenic salt consumption
Diabetes insipidus
Drug induced/iatrogenic

77

What is a water deprivation test and when would you use it?

Take all fluid away and measure urine specific gravity over succeeding hours if no signs of renal or cushings disease. Tests the ability of the kidneys to concentrate urine when water deprived.

78

What are the causes of urinary incontinence in the horse?

Reflex/UMN bladder
Paralytic/LMN bladder
Non-neurogenic

79

What are the causes of haematuria in the horse?

Urethral tears
Cystitis
Idiopathic renal haematuria
Neoplasia of bladder/urethra/penis/sheath
Drugs (NSAIDs)
Vaginal varicosities (in gravid mares)
Exercise induced haematuria
Non-urinary systemic disease e.g. acute myopathies

80

What causes equine cushing's disease?

Overproduction of proopiomelanocortin (POMC) peptides from pars intermedia (PI) which causes increased ACTH levels causing dysregulated cortisol production

81

List the clinical signs of cushing's disease.

Hirsutism
Hyperhidrosis
Laminitis
Lethargy
Fat redistribution
Weight loss
PU/PD
Polyphagia
Blindness
Seizures

82

What are the key diagnostic tools for cushing's disease?

Hirsuitism
Basal glucose >5.5mmol
Basal insulin >36IU/ml
Dexamethasone stimulation test (DST): give dex at 5pm then 12pm next dat, cortisol >1ug/dl at second test
Basal ACTH
Thyrotropin-releasing hormone (TRH) response test: measure basal cortisol, inj TRH IV, measure cortisol 30m post-injection, +ve if 66% increase

83

How can equine cushing's disease be treated?

Conservative: clip hair, regular laminitis monitoring/farriery, exercise if no chronic othopaedic disease
Medicate: if early case with hx of laminitis OR resting hyperglycaemia and sig increased insulin.... pergolide (dopamine agonist)

84

Which agents cause pediculosis?

LICE: Damalinia equi (biting) and Haematopinus asini (sucking)

85

Which agent causes chorioptic mange?

Chorioptes equi

86

What is the horse mite?

Trombicuoosis autumnalis

87

Describe the skin disease caused by oxyuris equi.

Pinworms which migrate from the small colon/rectum and lay eggs on perianal skin. Causes pruritis and tail rubbing.

88

Describe onchoceral dermatits.

Type 1/3 hypersensitivity to Onchocerca cervicalis microfilaria, transmitted by biting insects.

89

Describe the treatment of sweet itch.

Manage skin lesions
Corticosteroids
Immunotherapy/desensitisation treatment
Fly repellants
Prevent midges biting e.g. stabling at dawn/dusk, hooded rugs, insect-proof stables w/ ventilation

90

Which agent causes mud fever and rain scald?

Dermatophilus congolenis

91

Which agents cause ringworm in horses (and which is zoonotic)>

Trichophytan equinum var equinum/autotriphicum
Microspora gypseum/equinum/canis - ZOONOTIC

92

What causes purpura haemorrhagica?

Immune-mediated vasculitis associated with recovery from URT infection.

93

What are the clinical signs of purpura haemorrhagica?

Oedema of limbs
Serum exudation
Marked skin erosions
petechial/ecchymotic H+ of skin/mucosa
Pulmonary/cerebral oedema
Depressed + inappetant

94

List the different types of chronic rhabdomyolysis.

Recurrent exertional rhabdomyolysis
Idiopathic chronic exertional rhabdomyolysis
Polysaccharide storage myopathy (PSSM)- type 1 + 2
Glycogen branching enzyme deficiency

95

Which type of rhabdomyolysis is commonly seen in Quarter Horses?

Polysaccharide storage myopathy

96

How can chronic rhabdomyolysis be diagnosed?

Muscle biopsy
Exercise tests: 3 days after returning to work, take a blood sample pre and 3-6 hours post-exercise. Is the response of the muscle to exercise normal?
Fractional electrolyte excretion test
Genetic testing for specific myopathies

97

How can chronic rhabdomyolysis be treated?

Dietary- reduced CHO diet with oils for supplementation if needed, don't feed in anticipation of work.
Adequate warm-ups for exercise
Avoid stress
Supplement with salt if intense exercise
Vit E/Se to soak up free radicals

98

What are the clinical signs of rhabdomyolysis?

These occur immediately post-exercise:
Sweating
Hot painful tense muscles- particularly femoral, gluteal and lumbar muscles
Red/brown urine
Slight gait change to full on reluctance to move

99

How can acute rhabdomyolysis be diagnosed?

Myoglobinuria
Clinical signs
Serum increased CK/AST/lactate dehydrogenase

100

How is acute rhabdomyolysis treated?

Rest
Analgesia- NSAIDs
Fluids- correct electrolyte balance
Steriods (??)
Calcium carbonate/gluconate if severe muscle damage
Sedatives to relieve anxiety and stop muscle spasm

101

How is botulism transmitted and caused?

Through forage (preformed toxin in big bale silage), toxicoinfection botulism (growth in GIT), wound botulism.

Clostrisium botulinum toxin- blocks Ach releasae at neuromuscular junctions and peripheral cholineric nerve terminals

102

What are the clinical signs of botulism?

Dysphagia
Dirty weak tongue
Increased salivation
Weakness/trembling
Tail flaccidity

103

What are the clinical signs and cause of shaker-foal syndrome?

Toxicoinfectious botulism in foals

Slow PLR
Ptosis
Dysphagia
Reduced tail tone
Constipation and urine retention

104

How is botulism diagnosed and treated?

Identify toxin in serum/GI contents/silage
Treat: a/bs if toxicoinfectious/wound, antitoxin (US)

105

How is tetanus caused?

Clostridium tetani exotoxins:
Tetanolysin: local tissue necrosis
Tetanospasm: prevents release of inhibitory neurotransmitters in CNS causing spasmic contractions of striated muscle

106

What are the clinical signs of tetanus?

Extended head and neck (stiff)
Depressed
Sweating
Dysphagia
Tachycardia
Drooling
Generalised muscle contractions provoked by stimuli e.g. touch, sound

107

How can tetanus be treated?

If recumbent- euthanise.
Management: quiet gentle handing, dark stable, soft moist food with elevated food/water troughs
Antitoxin
Penicillin
ACP (reduces stimuli)

108

Which factors may influence clinical pathology results?

Different labs
Breeds: athletic v. drafts/ponies
Age
Sample collection
Sample handing
Physiological

109

Which enzyme is liver-specific in horses?

Glutamate dehydrogenase (GLDH)

110

Which enzymes indicate liver damage in horses?

AP, GGT, GLDH

111

Which enzymes indicate biliary stasis in horses?

AP + GGT

112

Which enzymes indicate muscle damage in horses?

CK, AST and lactate dehydrogenase

113

What are the causes of leucocytosis?

1. Inflam
2. Adrenaline release
3. Corticosteroids
4. Neoplasia

114

Whats the normal specific gravity of equine urine?

SG 1.020-1.050

115

Give examples of cases where antibiotics are usually NOT needed.

Strangles with only lymphadenopathy
Subsolar abscess
D+
Viral infections

116

Why shouldn't TMPS be used with alpha-2 agonists?

Risk of fatal cardiac arrhythmias

117

What are the adverse effects of using aminoglycosides in horses?

Nephrotoxic
Ototoxic
IM- muscle irritation

118

What is the vaccination regime for equine influenza?

1st from 4-6m, 2nd = 3-12 weeks later, 3rd = 5-7m later. Annual boosters

119

What is the vaccination regime for tetanus?

Toxoid- 2 vaccinations 1 month apart, then boosters every 2-3 years.
Antitoxin to all foals if mare not vacc within 24hr birth.

120

What is the vaccination regime for equine herpes?

Initial course 1 month apart, then boosters every 6m. Pregnant mares at 2/5/7/9m preg.

121

Which part of the passport must be signed for a horse to be declared not intended for human consumption?

Section 9 - must be signed by owner

122

What are the IgG levels for a normal foal, a foal with partial FPT and a foal with full-blown FPT?

Norm >8g/L
Partial = 4-8g/L
Complete

123

What is the treatment of a foal with FPT?

24 hours: 1-2L equine plasma IV (1L over 1hr, then the rest more slowly)

124

Which alloantigens do foals with neonatal isoerythrolysis have?

Aa and Qa

125

What are the signs of neonatal isoerythrolysis?

Icterus
Anaemia with weakness
Haemoglobinuria
Depression
Anorexia
Collapse + death

126

How is neonatal septic meningioencephalitis diagnosed?

Increased CSF protein
Neutrophilia

127

What are the causes of patent urachus?

Navel ill
Septicaemia
Increased abdominal pressure e.g. due to straining with retained meconium
Prolonged recumbency

128

What is the urachus?

Structure connecting foetal bladder to allantoic cavity

129

What is foal heat diarrhoea?

Transient self-curing D+ occuring due to altered colonic microflora during milk to grass fed diet transition

130

What is the most common cause of D+ in the foal?

Rotavirus

131

How is rotavirus prevented?

Vaccination in 8/9/10th month of gestation

132

What are the causes of gastroduodenal ulceration in the foal?

Stress
Iatrogenic e.g. NSAIDs
Infections

133

What treatment is given for neonatal gastroduodenal ulcers?

Omezaprole

134

What are the clinical signs of meconium retention?

Restlessness
Straining
Lifting tail
Lying on back and rolling

135

How is meconium retention treated?

Warm soapy water enema with soft tube inserted 10-12 inches + GRAVITY!
If doesn't work- oral paraffin stomach tubed
Analgesia

136

What is the cause of uroperitoneum in the foal?

Ruptured bladder (from increased abdo pressure during parturition)
Patent urachus/ureters

137

What are the clinical signs of uroperitoneum in the foal?

Abdominal distension
Lethargy
Tachypnoea
Tachycardia
Mild abdo pain

138

How is uroperitoneum diagnosed?

Peritoneal fluid analysis demonstrates creatinine : serum ratio > 2:1
Abdo U/S

139

How is uroperitoneum treated?

Drain abdo, admin IV saline and dextrose, a/bs. When stable- surgical bladder closure.

140

Describe the clinical signs of african horse sickness.

Affects endothelial cells causing visceral/body cavity effusions.
PULMONARY = PYREXIA, severe dyspnoea, peracute, 95% mortality- death within hours
CARDIAC = PYREXIA, s/c oedema of head/neck, acute, 50% mortality- death within 4-8d
Can also have mix of the above or 'Horse sickness fever' = subclin or with pyrexia and anorexia

141

What is the cause of ryegrass staggers?

Certain weather- endophytes in grasses produce neurotoxic alkaloids causing staggers in grazing animals to prevent overgrazing

142

What are the clinical signs of ryegrass staggers?

Hypometric ataxia
Proprioceptive deficits
Wide-based stance
Muscle tremors
Ataxic eyeball movements

143

What are the clinical signs of monensin poisoning?

Ataxia
Muscle weakness
Anorexia
Colic
Sweating
Haemolysis
Myoglobinuria
ORGAN FAILURE

144

List toxic plants to horses.

Yew
Ragwort
Cardiac aminoglycoside-containing plants e.g. foxglove
Seleniferous plants
Oak/acorns