Locomotion Flashcards
What are the 4 most common causes of lameness in dairy cows?
- sole ulcer
- white line diseaes
- digital dermatitis
- foul
What is the most common area for lameness in dairy cattle?
Hind feet - especially lateral claw
Describe the mobility scores for lameness in cattle (0-3).
0 - walks with even weight bearing and rhythm on all 4 feet
1 - steps uneven or strides shortened - affected limb or limbs are not immediately identifiable
2 - uneven weight bearing on a limb that is immediately identifiable - can keep up with the herd
3 - same signs as 2 but unable to walk fast - can’t keep up with herd
What is the pathophysiology of sole ulcer? What is the best form of treatment?
Form from horn overgrowth (usually lateral claw of hindfoot) –> weight distributed to heel –> bruise and poor horn growth –> hole (ulcer) forms
Corium usually prolapses out of ulcer
Tmt = trim, block, anti-inflammatory
(topical abx can be used as well)
What are some causes of white line disease?
- thin and soft horns - more likely to get penetration injuries
- Wet conditions - softens the horn
- Stones, foreign bodies
What is the most common bacteria found in digital dermatitis in cattle?
Treponemas bacteria (anaerobe)
What is the most common cause of foul (in-the-foot) in cattle?
Foreign bodies/sand between the claws –> buildup of Fusobacterium necrophorum
What are some common infections that cause lameness in sheep?
Ovine interdigital dermatitis (OID)
Footrot
Contagious ovine digital dermatitis
Joint ill
What is the predisposing condition for footrot in sheep?
Ovine interdigital dermatitis
Start with superficial, mild infection –> Dichelobacter nodsus proliferating –> kertolytic proteases invading the interdigital skin –> allows penetration of F necrophorum–> lesions under the horn
** if there is not OID lesion - D. nodosus CANT establish an infection **
What is the treatment for footrot?
ABX - parenteral (amoxy LA) and topical
Can use vaccine therapeutically
PREVENT with foot-bathing and cull repeated offenders Foot trimming has no role in prevention
How does contagious ovine digital dermatitis differ from footrot?
CODD infections commence IN THE SKIN ABOVE THE CORONARY BAND - lesions are ulcers that progress by separating the skin-horn junction
Footrot starts at the interdigital skin
What bacteria are present in joint ill in sheep? Where does the infection originate?
Streptococcus - usually dysgalactiae.
Infection usually originates from navel/poor colostrum
What is the point of trimming horse hooves?
THERE IS NOT ONE!
Just kidding…
To increase contact surface area with the ground and to increase the uniformity of wall contact
What is the weak point of a horse’s hoof?
The white line - can get abscesses here
This is why shoeing is mostly done in this location
What are 2 farriery related problems that can lead to abscessation of the hoof?
- Nail prick - the nail is driven through the sensitive laminae
- Nail bind - the nail is driven too close to the sensitive laminae
What are some common symptoms seen with navicular syndrome in horses? What is the best nerve block for diagnosis?
Usually affects the front feet –> low grade bilateral lameness that progresses slowly
Can be seen if exercised on hard ground or walked in a circle
Palmar digital nerve block
What attaches the dermal lamellae to the epidermal lamellae?
HEMIDESMOSOMES
What are the three forms of laminitis?
- Sepsis-associated - sickness –> endotoxin absorbed in blood
GI disease - intestinal compromise= strangulation/lipoma, pneumonia, septic metritis - retained placenta - Endocrinopathic - MOST COMMON CAUSE IN UK - associated with EMS, PPID, exogenous glucocorticoids - from prolonger hyperinsulinemia - NOT RESULT OF INFLAMMATION
- Excessive-weight bearing (supporting limb lameness) - severe, prolonged lameness in one leg can cause laminitis in the other leg - likely due to inadequate perfusion
What are clinical signs of laminitis?
Lameness normally affecting 2 or more limbs
Characteristic stance - leaning back from front limbs
BOUNDING digital pulses
Increased hoof wall temperature
Pain on hoof tester pressure
Palpable depression all the way around the coronary band
What are good diagnostic tests with a suspected laminitis case?
- Lateromedial radiographs - see if P3 has moved - if >11.5º = significantly reduced prognosis
- Endocrine tests - PPID/EMS
With endocrinopathic laminitis, what is the priority treatment?
REDUCING NSC (non-structural carbohydrates - fructan, starch, sugar)
Manage pasture to encourage growth with fertilizer - when pasture growing - decreased NSC content
Base diet on FORAGE and FIBER - if they need extra energy use vegetable oil or unmollassed beet pulp
* Can also use PERGOLIDE with PPID = dopamine agonist *
What is the most common sign seen with forelimb lameness in dogs/cats?
HEAD NOD - head sinks on sound leg
can also see stride alterations, short stepping, limp
What is the most common problem seen with shoulder injuries in small animals? How is it diagnosed and treated?
OSTEOCHONDROSIS DISSECANS - a condition of the developing cartilage and its supporting bone - often seen in young animals/high-performance animals
Cartilage does not become bone, necrosis occurs leading to a thick incompetent area of cartilage
DX WITH RADS - will see a flap present on the bone
Can also use contract arthrogram - will see the thickened area of cartilage
TMT = REMOVE FLAP
What is the most common problem seen at the elbow joint in small animals? How is it diagnosed and treated?
ELBOW DYSPLASIA –> osteoarthritis
Usually due to developmental pathologies - most common being the fragmented medial coronoid process ~95% of cases - will see an outturn of the paw, head nod, and muscle atrophy in the affected limb
Overloaded bone –> microfractures
DX WITH RADS OR CT (BEST FOR MEDIAL CORONOID PROCESS)
TMT = conservative with NSAIDs, hydro PT
Arthroscopy - remove fragment and decrease pressure in area
** SCREENING PROGRAM IN PLACE FOR ELBOW DYSPLASIA –> breeding out**
What is the most common cause of cranial cruciate ligament disease in dogs?
Degenerative weakness - diseased before rupture
What is the role of the cranial cruciate ligament?
Knee stability - preventing cranio-tibial translation
What are the stability tests used to assess the cranial cruciate ligament?
- Cranial drawer test - grip the leg with finger on patella and make a box with your pointer fingers/thumbs - see if tibia will move cranially to femur
- Tibial thrust - mimics walking - flex and extend the foot and have a finger on tibia - TIBIA SHOULD NOT MOVE YOUR FINGER
What is are the surgical treatment options for CCL rupture?
- Intra-articular - fixing from within the joint
- Extra-articular
- Osteotomy technique - TPLO or TTA
TPLO - tibial plateau levelling osteotomy
TTA- tibial tuberosity advancement
What is a common hindleg problem often seen in small dogs?
PATELLAR LUXATION
Abnormal tracking of the patella - NOT CONGENITAL
Developmental problem (usually medial) deviation of the patella
Signs show intermittent lameness, skipping lameness, muscle atrophy, effusion
What is a common hindleg problem seen in medium to large breed dogs? How do we diagnose/treat it?
HIP DYSPLASIA
This is a developmental disease where laxity begins around day 30 of life and onwards
Laxity –> inflammation –> microfractures of acetabulum –> new bone formation on femoral neck
Signs = bunny hopping, hard to stand, won’t exercise as much, lameness, muscle atrophy
DX WITH RADS - extended legs to see femoral head in hip joint - see osteophytes, thickened joint capsule, flat femoral head -> establish severity by looking at FEMORAL HEAD COVERAGE (should be 50% min)
TMT = conservative with regular short amounts of exercise, hydrotherapy, PT, diet - keep lean/loose weight, NSAIDs
Surgery = improve “fit” of the hip, pelvic osteotomy, arthroplasty to remove diseased tissue
Total hip replacement
What is the most likely differential diagnosis of a dog with a dropped hock?
Ruptured achilles/calcaneal tendon (will present with hyperflexed digits - crablike foot)
OR sciatic nerve damage (digits are normal)
What occurs in Legg Calve Perthes disease? What is the treatment?
Ischemia of the femoral head —> necrosis –> collapse when walking –> revascularization and new bone formation –> OA
TMT = femoral head and neck incision
What is the #1 contributing factor to osteoarthritis?
OBESITY (and age)
What are the most common sites of osteosarcoma in the forelimb/hindlimb?
Forelimb - away from the elbow
Hindlimb - towards the stifle
Predilection for metaphyseal regions
Proximal humerus, distal radius, distal femur and proximal and distal tibia in dogs. Cats have no preferential sites. Heads in horses and cattle.
What is the number one site of metastasis for osteosarcoma?
LUNGS!
Always want to do thoracic rads when suspected or confirmed osteosarcoma
What is the most likely type of tumor involved with a digital mass in dogs/cats?
SCC
Present with lameness, lesion, ulceration
TMT = amputation
When taking bloods for suspected osteosarcoma, what are two factors that contribute to the prognosis?
ALP and Cholesterol levels
What are two important diagnostic tests to confirm osteosarcoma?
FNA - 97% specificity and sensitivity
RADS - can see lysis, loss of cortical density, and new aggressive periosteal bone formation
ALP (increases from bone breakdown) and Cholesterol are important in prognosis as well
What are the options for treatment of osteosarcoma?
AMPUTATION
AMPUTATION + Chemotherapy
Limb sparing + Chemotherapy (usually has same survival time as amputation + chemo)
Euthanasia
What is the prognosis for osteosarcoma in a cat?
Guarded-Good (better than dogs)
Not as high likelihood of metastasis
Amputation can be curative
What are common causes of osteomyelitis? Treatment?
Post-trauma/post-surgical or hematogenous
TMT = abx systemic and local
If implant (corrective, prosthetic) present - REMOVE
Debridement
Sequestrum present - REMOVE
How can osteomyelitis form a sequestrum?
Inflammation –> ischemia, limits the body’s ability to heal –> sequestrum and acts as FB in bone –>bacterial/fungal burden or osteolysis
What kind of hypersensitivity is immune-mediated polyarthritis?
TYPE 3 BITCH!
Leads to an antigen/antibody complex in the synovium
CARPI AND TARSI most commonly affected
Large amounts of IgG plus Ag lead to microprecipitates which settle out in the joints and cause the clinical signs associated with immune-mediated joint disease.
What is the most common form of non-erosive immune-mediated polyarthritis?
TYPE 1 = idiopathic (~50% of cases)
can also be associated with infection, GI disease, neoplasia
On a synovial fluid analysis, what is the most common cell seen with IMPA?
NEUTROPHILS!
What is the main treatment for IMPA?
IMMUNOSUPPRESSION with prednisolone
+ / - = cytotoxic drugs - cyclosporin, azathiorpine
RA - needs more aggressive and prolonged therapy
Why is gout seen in birds/reptiles?
Crystal induced arthritis because they do NOT HAVE URICASE ENZYME –> increased amounts of uric acid and urate that accumulate in the joints
What are some common conditions that cause degenerative joint disease?
Trauma
Infectious inflammation
Non-infectious inflammation - auto-immune disease
Developmental disease - dysplasia, limb deformity, osteochondrosis
What is the pathophysiology of degenerative joint disease?
- degeneration of articular cartilage –> inflammation
- Synovial membrane releases - PGEs, leukotrienes, cytokines
- Subchondral bone exposure - WHERE THE PAIN RECEPTORS ARE LOCATED
What is the most potent route to give anti-inflammatory for horses with DJD?
INTRA-ARTICULAR corticosteroids
What are common joint supplements for horses with DJD?
Matrix glycosaminoglycans (GAGs) - Glucosamine
Sodium hyaluronate - acts as a lube/anti-inflammatory
Green-lipped mussel extract
Methylsulphonylmethane (MSM)
PRP - platelet-rich plasma
Stem cells
Why does osteoarthritis occur?
A homeostatic imbalance between anabolic and catabolic capabilities of cartilage cells and poor capacity of cartilage to repair itself –>
DECREASE IN RATIO of water, collagen type 2, and proteoglycans in the ECM
What is the most common tendinopathy in horses?
Superficial digital flexor tendinopathy
Palmar metacarpal swelling. pain on palpation
* can see core/central lesion on US *
Where is the most common site of suspensory ligament desmitis? What are the clinical signs?
The proximal region of the hindleg
Straight hock, overextending fetlock, lameness
What are some presenting signs of equine back pain?
Poor performance, bucking, rearing, sensitivity when brushing, “cold back” = dip back when rider gets on
When lunging a horse with a potential back problem, what is one thing to look for?
CANTERING DISUNITED - outside limbs should land first then the inside legs - if they do not land like this = disunited
What are differentials for equine back pain?
Osteoarthritis Spondylosis Supraspinous ligament desmitis Sacroiliac joint pain Lumbosacral join paint
What is NOT a good treatment option for a cow with a sole ulcer?
Use of an antibiotic foot bath would be inappropriate. It would have little or no effect on the lesion.
What is interdigital dermatitis in cattle?
A mild inflammation of the skin in the interdigital skin, frequently not recognized in the UK.
Most causes of ovine lameness originate at what site in the sheep’s foot?
INTERDIGITAL SKIN
OID, footrot and foot abscesses all occur as a result of initial infection of the interdigital skin. Wet underfoot conditions and damage to the skin allow colonisation with Fusobacterium necrophorum and further penetration by other organisms. The interdigital skin should always be carefully examined during clinical examination of the foot.
What would be the most appropriate treatment strategy for a sheep with footrot?
Apply topical antibiotic spray, give injectable antibiotics and keep in a dry environment
Footrot usually results in a superficial and deeper infection so both injectable antibiotics and topical antibiotic spray on the affected foot are recommended. Analgesia could also be considered. There is some debate about whether to trim the hoof horn of affected feet – a gentle trim to help reveal the extent of the lesions may be useful but hard trimming and damage to the foot should be avoided.
What is the most likely diagnosis for a horse with swelling localized to the proximal palmar metacarpus and dorsal to the flexor tendons?
Desmitis of the accessory ligament of the deep digital flexor tendon
Treatment of a superficial digital flexor tendon over-strain injury by controlled exercise should be monitored most appropriately by:
Serial ultrasonographic assessment and cross-sectional area measurement - CSA should not increase by more than 10% at successive ultrasonographic assessments which should be performed at approximately 3 monthly intervals
more than 10% increase means too much exercise happening
How long does it take for surgically repaired tendons to recover 50% of normal strength?
6 weeks!
What is the main sign of Common Calcaneal Tendon rupture in the dog?
Hyperflexion of the hock
The common calcaneal tendon acts to extend the hock therefore when it fails, hyperflexion of the hock is observed
What is the main function of the Common Calcaneal Tendon and associated muscles?
Extend the hock joint
A horse with osteoarthritis of the distal interphalangeal (DIP) joint should block to:
Palmar digital and DIP joint
What is one joint fluid characteristic of inflammatory arthropathies?
Reduced viscosity - Due to the effusion and breakdown of hyaluronic acid, the viscosity of inflammatory joint fluid is decreased.
True or false: When performing an arthrodesis in a dog, opposing joint surfaces should be contoured.
TRUE BITCH!
What are the phases of stride in a horse?
- limb lands - can slide if on a slippery surface
- fetlock extension - fetlock drops and flexor tendons LOADED - energy of stride stored
- Fetlock goes back up into normal position into stance phase
- Breakover into swing phase - breakover initiated by heel leaving ground and toe pivot
Describe the rhythm of a horse walk. Can you see lameness on a walk?
Even rhythm 4 beat gait
If you see lameness when walking, usually a major problem. Can see subtle lameness though.