Locomotion 3

Question 1

What is the developmental process that is usually responsible for arthrogryposis and what do the affected joints look like once they are opened post mortem?

Answer 1

primary central or peripheral nervous system insult that causes inadequate muscle development in utero
- only in severe forms are there any associated deformities of the articular surfaces

Question 2

what species is patella subluxation or luxation common

Answer 2

common in dogs and also seen in horses

medial luxations predominate in dogs, especially small breeds

Question 3

What are the key abnormalities in canine hip dysplasia

Answer 3

○ small pelvic muscle mass relative to pelvis size (with the discrepancy exacerbated by feeding for maximal growth rate) -> lack of conformity between the femoral heads and the acetabula (acetabulum too shallow) -> laxity and subluxation of the coxofemoral joints - movement of femoral heads out -> DJD

Question 4

What is the key difference between degenerative joint disease and arthritis

Answer 4

inflammation is primary in degenerative it is secondary

Question 5

what are the 3 ways infectious agents get into joints and What is the most common route of entry?

Answer 5

1) haematogenously - the most common route
2) by direct extension from an infectious focus in adjacent soft tissues or bones
3) via a penetrating wound (including pressure sores and iatrogenic infections)

Question 6

In which species is infectious arthritis commonly diagnosed? What age of animal is most commonly affected

Answer 6

infectious arthritis is especially common in livestock, especially young animals

Question 7

What are the major differences (grossly and prognostically) between fibrinous arthritis and suppurative arthritis?

Answer 7

Grossly - the earliest change is oedema and hyperaemia of the synovium +/- petechiation
- the volume of synovial fluid increases and the fluid becomes slightly turbid and floccular
yellow-grey fibrin deposits may be present over the synovium, articular cartilages or in joint recesses
- complete lesion resolution most common
Grossly - marked enlargement of the joint area +/- abscessation or fistulation to the skin surface
prog - chronic

Question 8

What are the 2 forms of immune-mediates arthritis pathogenesis, lesions and prognosis

Answer 8

1) Erosive - the antigen triggering inflammation is persistent in the synovium -> erosion of the synovium
- subluxation/luxation +/- ankylosis
- flamboyant synovial villous hyperplasia
2) non-erosive – the primary disorder is extra-articular in location and may be transient,
- usually minimal or no synovial villous hyperplasia

Question 9

What are the major forms of immune-mediated arthritis seen in domestic animals? Which of these are erosive and which are non-erosive

Answer 9

Erosive
e.g. rheumatoid arthritis of dogs - chronic
Non-erosive
- systemic lupus erythematosus

Question 10

In which species is articular/periarticular gout common? What does it look like grossly?

Answer 10

• occurs in humans, birds and reptiles (species that lack the enzyme uricase)
• urate deposits (tophi) are white, caseous or pasty and periarticular and may be grossly visible

Question 11

What are hte 2 most serious forms of bursitis in horses and where found

Answer 11

1) Fistulous withers - involves the supraspinous bursa between the nuchal ligament and the spinous process of thoracic vertebra
2) “poll evil” - involves the atlantal bursa between the nuchal ligament and the dorsal arch of the atlas

Question 12

What is the typical behaviour of a synovial sarcoma and which other aggressive tumour can develop around joints in dogs

Answer 12

• most synovial tumours are malignant and destroy and cross the joint, penetrating the bones and causing bone lysis and periosteal reactivity
• less common tumours arising from synovium of joints or tendon sheaths in domestic animals include benign and malignant giant cell tumours

Question 13

Horse Hooves what occurs during compression

Answer 13

○ Caudal thinner than the cranial part of the hoof
○ Cranial is so it can land and take the force of the bones
○ Soft tissue in the palmar surface acts as cushion (as get faster land more palmar than toes)
§ To tip on the toes -> use flexors such as the deep flexor (inserts onto P3)

Question 14

What is the hoof and the 4 major regions

Answer 14

The Hoof is the hard keratinised covering of the third phalanx
Major regions of the hoof 
	1) Periople (and bulbs) 
	2) Wall (heels and bars) 
	3) Sole 
	4) Frog

Question 15

describe the wall and sole of the hoof

Answer 15

Wall of the hoof Toe + quarters (medial and lateral) + heel

Sole - between frog and the wall - epidermis forms pigmented intratubular and tubular horn

Question 16

Describe the frog of the hoof

Answer 16

• elastic material triangular in shape with a base and an apex
• Base is expanded and covered in periople which forms the bulb of the heels
• Groove marked by central groove and collateral (paracuneal) grooves separate frog either side from bar and sole

Question 17

Describe the bar and the white line of the horse hoof

Answer 17

Bar - where the wall folds back on itself -> similar material to the wall
- Either side of the frog (there are two)
White line - between the sole and the wall of the hoof - Region where infection can track up the hoof
JUNCTION BETWEEN - important when shoeing a horse
- Sensitive tissues - laminar dermis and Non-sensitive hoof - horn of stratum internum and stratum medium

Question 18

Describe the periople and coronet of the horse hoof

Answer 18

Periople - band of soft tubular and intratubular horn located between the normal skin of the left and the wall of the hoof
- Perioplic epithelium overlies the perioplic dermis which forms the horn of the stratum externum
○ Spreads a short way down the hoof forming a thin waterproof coating
Coronet/corona - the region where the haired skin meets the hoof

Question 19

Hoof wall what is the composition

Answer 19

• Tubular and intertubular horn produced by epidermis covering the coronary dermis
• Inner surface of the wall comprises fine leaves of lamina horn produced by epidermis of the laminar dermis covering the external surface of P3

Question 20

What are the 3 layers of the hoof wall and characteristics

Answer 20

1) Stratum externum - thin layer generated by the periople (tubular and intertubular horn)
2) Stratum medium - the major component of the wall (tubular and intertubular horn)
- Generally pigmented, inner wall isn’t where it becomes continuous with the laminar epithelium (that produces the str. Internum)
3) Stratum internum - fine leaves of keratin running parallel to the surface of the wall towards the ground (laminar horn)

Question 21

What are the 2 dermal regions associated with the hoof wall and what do they form

Answer 21

1) Coronary dermis - forms the stratum medium (main hoof wall)
2) laminar dermis - forms the stratum interum

Question 22

Coronary dermis what does it form and how

Answer 22

forms the stratum medium (main hoof wall)
- Forms the long papillae pointing towards the ground and supports the epithelium that produces the tubular and intertubular horn of the str. Medium
Concave proximal boarder of stratum medium is the coronary groove and contains coronary dermis in life

Question 23

Laminar Dermis what does it form and how

Answer 23

• Shaped into laminae which run parallel to the surface of the hoof wall and towards the ground
• Laminae have smaller secondary laminae (tissue dermis) arising from their lateral surfaces
• Overlaying epithelium forms non-pigmented horn of the stratum internum which grows downwards at the same rate as the horn of the stratum median
  ○ Similar growth rates means high integrity and strong union between them and the dermis (sensitive tissues) is maintained

Question 24

can the hoof regrow

Answer 24

Horn can heal and grow over the end of the hoof after removed as long as have dermis, blood supply and no infection

Question 25

List 4 differences between Cow and Horse

Answer 25

1) Periople is much wider
2) The sole is a narrow rim of horn adjacent to the wall and gradually merges caudally with the bulb
3) Coronary papillae are much smaller
4) The str. Internum is less extensive and bears no secondary lamellae

Question 26

What are the 4 steps in the systemic approach to reading MSK radiographs

Answer 26

1) Alignment -> limbs, bones, joint surfaces -> are they in contact - luxation
2) Bone loss and new bone production -> where occurring
3) Cartilage -> joint space and physes -> normally radiolucent, width, contour, contrast radiography may be needed
4) soft tissue -> swelling, atrophy or change in opacity

Question 27

List 6 advantages of using radiology for examining joints

Answer 27

1) readily available
2) inexpensive
3) relatively easy to perform
4) global ‘overview’ of lesions
5) detects many common lesions
6) monitor progress with follow-up examinations

Question 28

List 5 disadvantages of radiology for examining joints

Answer 28

1) limited evaluation of soft tissue
2) subtle pathology may not be visible
3) significant bone loss required before lesions are visible - need to lost 70% before see
4) lesions may not be visible on ‘standard’ views
5) superimposition of structures may make interpretation difficult

Question 29

List 5 advantages of ultrasound for evalulation of joints

Answer 29

1) readily available
2) portable
3) evaluation of soft tissue structures
4) detect some lesions when radiographs are normal
5) monitor progress with follow-up examinations

Question 30

List 5 limitations of ultrasound for evaluation of joints

Answer 30

1) high quality equipment required - high frequency
2) excellent knowledge of joint anatomy required
3) can be difficult to image curved or ‘knobbly’ structures
4) limited information about bone lesions
5) not as sensitive as MRI for soft tissue lesions

Question 31

What is the advantage and disadvantage of scintigraphy for bone

Answer 31

Ad - sensitive at detecting areas of bone activity
Dis - is not specific for the disease process
KNOW WHERE THE LESION IS NOT WHAT IS IT

Question 32

List 4 Indications for computed tomography of the musculoskeletal system

Answer 32

1) sensitive detection of bone lesions
2) understand complex lesions in 3 dimensions
3) evaluate intra-articular structures eg. CT arthrography
4) evaluate relationship of bone lesion to surrounding soft tissue

Question 33

List 4 limitation of computed tomography of the musculoskeletal system

Answer 33

1) limited availability
2) expensive
3) uses radiation
4) soft tissue contrast - better than radiographs, not as good as MRI

Question 34

List the 3 indications for magnetic resonance imaging of the musculoskeletal system

Answer 34

1) Any MSK injury!
2) Joint lameness localised to a specific area, but other modalities do not show the lesion
3) Lameness localised to an area difficult to access by other means (eg. equine distal limb)

Question 35

List 4 limitations of magnetci resonance imaginf of the musculoskeletal system

Answer 35

1) limited availability
2) expensive
3) time to acquire study (30 - 40 mins)
4) Poor resolution of very small anatomy

Question 36

List the 6 radiographic signs of osteoarthritis

Answer 36

1) joint effusion/synovial thickening
2) osteophyte formation - bony spurs
3) enthesophyte formation
4) subchondral bone scleoriss
5) subchondral bone cysts
6) narrowing of joint space

Question 37

List 5 predilection sites for OC in the dog

Answer 37

• shoulder - caudal aspect of humeral head
• elbow - medial portion of humeral condyle
• stifle - lateral or medial
• femoral condyle
  tarsus - medial or lateral trochlear ridge of the talus

Question 38

What are the 5 main ligaments/tendons in the distal limb of the horse and where do they run

Answer 38

1) Common digital extensor -> radius to P3
2) Deep digital flexor tendon -> radius to P3 + strong attachments to carpal sheath (half the tendon from the carpal sheath (accessory ligament of deep digital flexor tendon = distal check ligament)
3) Superficial digital flexor tendon -> radius to P2
- Has an accessory ligament (proximal check ligament) that originates from the distal radius
○ Only present in the forelimb
4) Intersseous - Originates from the palmar aspect of the carpus
- Bifurcates in the distal metacarpus before it inserts into the proximal sesamoids and branches to merge with the extensor tendon on the dorsum of the digit
Also called suspensory ligament
5) sesamoidean ligament

Question 39

Nuchal ligament what is it, where stretch and the 2 parts

Answer 39

• A thick double-layered yellow elastic sheet of ligament
• Stretching between the dorsal spinous processes of the first few thoracic vertebrae (the withers in the horse) with connections ventrally to the spinous processes of the cervical vertebrae from C3 to C6
  1) Funicular portion - long strap - lose tone when horse head close to chest
  2) Laminar portion -

Question 40

What is the difference between the horse and the dog nuchal ligament

Answer 40

No funicular part and the nuchal ligament attaches to the spinous process of the axis not directly to the skull

Question 41

What is the function of the stay apparatus of the horse and the 2 things it consists of

Answer 41

combination of structures, and especially the elastic tendons and ligaments, which allow horses to rest while standing up -> passively support the trunk against gravity
1) medial patella ligament -> hooks over the medial epicondyle of the femur -> needs to be unlocked before can move
2) Reciprocal apparatus
○ (SDFT (superficial digital extensor tendon) +peroneus tertius (from the region of the extensor fossa of femur down to metatarsus))

Question 42

What is the function of the reciprocal apparatus, the tendons involves and what does this result in

Answer 42

ties the movement of the hock and the stifle together so reciprocal movement occurs

• SDFT (superficial digital extensor tendon) +peroneus tertius (from the region of the extensor fossa of femur down to metatarsus))
• When the hock flexes the stifle flexes
• When the stifle extends the hock extends
• This means that the driving force of locomotion can be directed through the lower hindlimb from the muscles at the top of the limb with minimal loss of power

Question 43

Bipedal hopping describe 3 important features that help it be energy efficient and which is most important

Answer 43

1) Hopping allows increase in stride length without increasing stride frequency
- Lose energy when hit the ground, need to decelerate and then reaccelerate so increase stride length
- Locomotor cost = muscle force/step x step frequency - MOST IMPORTANT
2) Distribution of muscle mass and high aerobic capacity
§ 50% of muscle is skeletal muscle in back
3) Elastic energy storage
§ If compress feed energy into spring and energy stored used to expand the spring

Question 44

Skeletal adaptations to bipedal hopping list 5 adaptations

Answer 44

1) Tibial length -> kangaroos tibial to femur 2:1, quadrupeds generally 1:1
2) Long strong tail that touches the ground
3) Really short front forelimbs
4) Neck is a lot shorter
5) Bipedal hopping results in increased joint loads -> Especially the hock and foot
1. fibrocartilaginous petalla
2) fibrous cartilage cushions in tibial plateua
3) highly keratinised skin on palmar foot and fat pads - absorb forces

Question 45

The physics of flying what must be overcome and how

Answer 45

1) Lift must overcome weight (gravity)
○ Must start moving, air sucked under the bottom of the wing and increases air pressure above and decreases air pressure below -> LIFT
2) Propulsion must overcome drag
○ Flapping, dynamic soring etc. -> needed to get started before lift

Question 46

List the 3 main adaptations birds and bats have undergone to be able to fly

Answer 46

1) light skeleton - reduce weight
2) rigid and compact body
3) efficient muscular effort
- no excessive range of motion, birds - carpus flex auto with elbow, bats - elbow and digits flex auto with shoulder - don’t need special muscles for this, Birds and bats: keeled sternum (carina) -> large and flat sternum for attachment of the muscles

Question 47

List the 3 adaptations of bird wings to fly

Answer 47

1) Carpus reduced
2) Manus is reduced to 3 digits
○ Digits 1 and 3 are vestigial
○ Digit 1 forms the alula can be used for direction of flight
3) Propatagium - part of the limb that makes the wing
○ Ligamentum propatagiale

Question 48

List the 3 adaptations of bat wings to fly

Answer 48

1) Distal part of ulna rudimentary -> most is just radius
2) Elongated digits -> 5 fingers -> first digit generally has a claw
3) Patagium
○ Plagiopatagium generally takes up the whole wing

Question 49

Flight muscles in birds and cats and where is the point of rotation

Answer 49

BIRDS
Pectoral muscles up to 1/3rd of body mass
1) Pectoralis muscle
- Contract when fly downwards
2) Supracoracoideus
Point of rotation for movement of wings - Shoulder joint
BATS
17 muscles involves
Point of rotation - where clavicle meets the sternum - not fixed but moves

Question 50

List the 4 main adaptations of fish to swim and the 2 types of active propulsion

Answer 50

1. Spindle shape (tuna)
2. Lack of external ears of genitalia - provide drag
3. Lack of or reduction of limb segments
4. Smoothness of skin
   Need to achieve active propulsion
   1) Undulatory swimmers
   2) Oscillatory swimmers

Question 51

Undulatory swimming what does it involves and which animals

Answer 51

• The body axis or long dorsal and ventral fins, acts as propulsions, creating an undulating (wave-like) motion
• Most fish, seals and dolphins

Question 52

Oscillatory swimming what does it involve and which animals

Answer 52

TURTLES

• Paired appendages (fins, flippers, limbs) are used to achieve propulsion
• Power stroke -> movement of limb segments vertically then horizontally

Question 53

What are the 3 adaptations of the limb needed for oscillatory swimming

Answer 53

1. Lengthening of bones of “hand” - act as flippers
2. Extension of integument
3. Dorsoventral flattening of radius and ulna
   - Strong and complex forelimbs muscles

Question 54

What are the following called in the horse:

P1, P2, P3, Metacarpal 2,3,4

Answer 54

P1 = coffin bone 
P2 = short pastern 
P3 = long pastern 
Metacarpal 3 = cannon bone
Metacarpal 2 and 4 = splint bones -> have what they call "buttons" on the end of the splint bones

Question 55

What are the following called in the horse:

tarsal joint, P1-P2, P2-P3, Metacarpal phalangeal joint, carpal joint

Answer 55

Tarsal joint = hock
Tarsal joint = hock
P1-P2 = pastern joint (proximal interphalangeal joint)
P2-P3 = coffin joint (distal interphalangeal joint)
Metacarpal phalangeal joint = fetlock joint
Carpal joint = knee

Question 56

How to determine between the hind and forelimb of the horse and the lateral and medial view

Answer 56

Forelimb - base of the hoof tends to be more circular -> 60% weight bearing -> circular is better equip to
Hindlimb - base of the hoof tends to be elongated -> 40% weight bearing
Medial view - has the metacarpal tuberosity
Lateral view - has the lateral digital extensor alongside the common digital extensor

Question 57

What is the chestnut and ergot in the horse

Answer 57

Chestnut - an oval region of flaky keratin on the medial aspect of the forearm just proximal to the carpus or just distal to the tarsus in the hindlimb
Ergot - found on the caudal aspect of the fetlock -> thought to be a remnant of the metacarpal pad

Question 58

The vessles and nerves of the distal limb in the horse what are they and where they course

Answer 58

Medial palmar artery ->
1) Medial and lateral palmar arteries -> b/n interosseous and the flexor tendons
FETLOCK JOINT -> become laterla and medial digital arteries dorsal and palmar branches that anastomse to form ring around P1, 2 and terminal around P3
2) Medial and lateral palmar metacarpal arteries etc. -> distally on palmar surface of the M3 deep to the interosseous ligament

Question 59

What is the order of ligaments and tendon to the bone on the fetlock

Answer 59

Annular ligaments (palmar annular ligament) -> tendons (superficial and deep digital flexor) -> scutum (proximal) -> sesamoids (proximal)

Question 60

List the 3 annular ligaments in the distal hindlimb of the horse

Answer 60

• Palmar annular ligament of the fetlock
• Proximal digital annular ligament
• Distal digital annular ligament

Question 61

Besides the sesamoidean and main ligmanets what other ligaments present in the hind-limb

Answer 61

P1-P2 = pastern joint = proximal interphalangeal joint
Caudal to lateral
1) Axial palmar ligaments X2
2) Abaxial palmar ligaments X2
3) Collateral ligament of the fetlock (lateral and medial)
P2-P3 = coffin joint = distal interphalangeal joint
Also has a collateral ligament

Question 62

List the 7 main sesamoidean ligaments and where they course

Answer 62

1) interosseous
2) intersesamoidean (palmar) - unites with the two axial surface of the sesamoid bones
3) Collateral - medial and lateral ○ Attach the abaxial surfaces of the sesamoid bones to the distal extremity of the metacarpal bone and the tuberosity of P1
4) Straight - from base of each sesamoid to P1 & P2
5) Oblique - either side of straight run to palmar surface of P1
6) cruciate - deep to oblique and straight, from the base of one sesamoid to the proximal P1 - cross over
7) short - from base of each sesamoid to underlying region of P1

Question 63

Why would the fracture of the proximal sesamoid bone be a severe problem

Answer 63

• Part of the suspensory apparatus of the fetlock joint

Question 64

What is the function of the check ligament

Answer 64

• Extra pull on deep digital flexor on P3

Question 65

What would be the best site for arthrocentesis of the fetlock joint

Answer 65

• Lateral aspect distal to the button of the splint bones

Question 66

4) What would happen to the horses stance if
a) The superficial flexor tendon was severed
b) The deep digital flexor tendon was severed
c) Both the superficial and deep flexor tendons were severed
d) The interosseous (suspensory) ligament was severed

Answer 66

a) Hyperextension of the proximal interphalangeal joint and fetlock joints
b) Hyperextension of the distal interphalangeal joint and fetlock joints
c) Hyperextension of the proximal and distal interphalangeal joints and fetlock joints
d) Hyperextension of the fetlock

Question 67

What are the 3 main manifestations of MSK injury

Answer 67

1) pain
- poor performance, lameness, reluctant to move, recumbency
2) mechanical dysfunction
3) inflammation

Question 68

What are the 2 first steps of lameness analysis

Answer 68

○ Determine limb/limbs
1. Examination of gait - often multiple - which leg is animal unweighting, head goes down on good forelimb
○ Identify site/sites within limb
2. Examination of limb - palpation, manipulation, swelling, heat

Question 69

Swelling what are the two main swelling in limbs and causes

Answer 69

1) joint swelling
1. effusion - fluid swelling - dorsal and palmar pouches (fetlock)
2. joint capsule thickening
3. periarticular swelling
2) tendon sheath swelling
- effusion
- acute tendon injury
- healed tendon

Question 70

inflammatory due to infection or other process how to determine

Answer 70

cannot determine clinically need to test the synovial fluid

Question 71

List the 4 main modalities for imaging bone and what good for

Answer 71

1. Ultrasound
○ Swelling and inflammation
○ Structural integrity
2. Radiography and CT
○ Structural integrity of bones 
○ Secondary changes associated with osteoarthritis -> osteophytes and local areas of lysis 
3. Scintigraphy
- Blood flow -> inflammation increase blood flow 
- Osteoblastic activity -> increase bone turnover, increase blood flow 
4. MRI
- Swelling
- Structural integrity
- Fluid, fat accumulation

Question 72

How do you locate pain in a lame animal

Answer 72

NERVE BLOCKS

Question 73

What are the 3 questions ask with choice of modality and examples

Answer 73

1) Has source of pain been localised?
○ No – use a screening modality - scintigraphy 
○ Yes – localised imaging - Ultrasound, MRI
 2) Which tissues do I need to image?
○ Bone – RGs, CT, scintigraphy
○ Soft tissue – ultrasound, MRI , CT
3) What is available?
○ RG, US -> stock standard 
○ MRI, CT, scintigraphy require referral

Question 74

Site of injury list 4

Answer 74

1) direct trauma
2) overload injuries
3) developmental
4) sepsis -> superifical, haematogenous (synovial)

Question 75

Management of injury what has limited healing, slow and intermediate healing

Answer 75

Limited - articular structures, cruciate ligaments
Slow - tendons, extra-articular lig - collateral
Intermediate - subchondral bone

Question 76

What are the 2 main forces involves with locomotion and other important feature

Answer 76

• Force of body on ground -> animal puts force on the ground
• Ground reaction force -> ground pushes up towards the animal -> reciprocal of force of body on ground
• Moment (Torque)
- The rotation action produced by a force

Question 77

What does a tendon wrapping a joint result in and how do animals work with this

Answer 77

-> large tendon loads -> large joint contact forces
Elephant -> avoid large moment arms with straight limbs
Efficient animals use large moment arms to allow elastic energy storage in tendons that is then released during locomtion -> energy efficient

Question 78

What are the roles of the upper and lower limb of horses and example of structures and which takes higher load

Answer 78

Upper -> muscular power at the top, large moment arms created
Lower - passive spring to absorb then release energy
Eg - SDF, SL, DDF, Biceps
SDFT, SL take higher loads generally see most injuries

Question 79

Joint loads which joints longest to shortest moment arm

Answer 79

1) fetlock
2) carpus
3) PIP joint
4) DIP joint

Question 80

How does fatigue occur in the limb and how does it present in bone, tendon and cartilage

Answer 80

Effect of multiple loads
- Gradual degradation of material properties due to multiple loads
○ Larger the bend the smaller the number of times you need to bend to lead to failure
○ High strains lower number of cycles to failure, low strains higher number of cycles to failure
- Bone
○ Microcracks form due to fatigue
- Tendon
○ Core degeneration due to fatigue
- Cartilage
○ Focal degeneration
§ More resistant then bone that generally fatigues first

Question 81

List 4 fatigue injuries

Answer 81

1) stress fractures -> severe lamness following fast excercise
2) subchondral bone injury -> often chronic -> osteoarthritis -> fracture
3) tendon straing - swelling and pain
4) cartilage degeneration

Question 82

List the 3 main ways to deal with fatigue

Answer 82

1) Over engineer
- Fatigue life of tissue greater than fatigue life of the animal
2) Replace
- Tissue turnover and bone - increases fatigue life
3) Adapt
- Keep strains manageable by increasing the strength
Bone good -> increase thickness of bone, tendon and cartilage limited

Question 83

Is remodeling of bone good or bad

Answer 83

• Focal remodelling implicated in stress fracture propagation
• Resorption spaces decrease bone strength and stiffness
• Replaces fatigued bone - reset the bone fatigue time
• Weakens bone

Question 84

List and describe the 4 main ways to prevent fatigue in racing animals

Answer 84

1) allow adptation -> most responsive in younger animals
2) maximise repair
3) adequate rest periods - at least 3 months
4) reduce load
1. body weight -> greater effect on SDFT
2. moment arm - determined by centre of pressure of the foot -> conformation of foot -> farriers are increase heal height and decreasing point of the toe -> moving centre pressure of the foot
3. speed - Effect of increasing speed of gait
○ Increased GRF (ground reaction force)
○ Increased fetlock GRF lever arm
○ Decreased SDFT moment arm - TRIPLE EFFECT

Question 85

If a dogs right pelvic limb is advanced more rapidly than his left and his hip bobs up when his left paw is in contact with the ground which limb is lame?

Answer 85

The left limb is the lame limb -> right limb is advanced quickly to reduce the time in which the lame left limb is bearing weight

Question 86

What is the most common cause of canine pelvic limb lameness and how to confirm and a way to fix

Answer 86

cranial cruciate disease
Sedated – pain on hyperextension, pain on attempted cranial subluxation, pain on internal rotation.
Modified Rtinacular Imbrication