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.
Describe the rhythm of a horse trot. Would you use this for a lameness exam?
Two beat diagonal gait
This is the best used to observe lameness
Why do we see a head nod with forelimb lameness?
Raising the head reduces the load put upon the lame limb.
How can you tell if there is hindlimb lameness in a horse?
They will hike up their pelvis when the lame limb is weight bearing.
Drifting - horse moving away from lame limb - lame limb tracks under body or is posted out - will look like they are not running in a straight line
How to tell if there is lameness in pigs?
Uneven weight distribution - head nods, hip hikes
Postural/conformation signs - dog sitting/arched back
Slowness
Shaking
Signs of inflammation
Muscle atrophy
What are some common signs of erysipelas in pigs?
Valvular endocarditis
Diamond skin shaped lesions
Lameness - usually single leg
What are symptoms seen with Mycoplasma hyosynoviae in pigs?
Multi leg lameness
Usually affects growing pigs
Usually no other clinical signs
How would you treat a sheep affected with CODD?
Parenteral antibiotic, topical antibiotic
Which products are used in sheep footbathing?
Zinc Sulphate, Formalin
When using formalin - sheep can walk through
When using zinc sulphate - sheep have to stand in it
There are a number of products some are proprietry - those based on Zinc sulphate are probably the best due to operator safety though disposal may cause issues due to its environmental safety.
Foot bathing can have unexpected problems and cause lameness itself through dip without bacterocidal or bacteriostatic additives or properties being used over two days. This presents as a sudden increase of lame animals in the flock. The dip remaining in the bath overnight allows the increase in bacterial load and small nicks in the skin allow bacterial penetration of the foot and a condition called post-dipping lameness. Which bacteria is most important in this condition?
E. rhusopathaie
never heard of this shit once in my life
What vaccine protects against lameness in sheep?
FOOTVAX
It is the only vaccine on the market. As with all products you should adhere to the datasheet.
You should vaccinate before periods of risk which probably overlap with footbathing.
When a new sheep enters a flock, how long should it be quarantined for?
28 days
You may have heard of ORF a viral skin disease of sheep (and humans). If you have this disease alongside D. congelensis. Which disease would these pathogens combine to cause?
Strawberry footrot
How many hours are dairy cows meant to lie down for?
At least 14 hours
The more the cow can lie down, the better it is to rest their feet and recover from the pressure put on their feet. A minimum is recommended of 14 hours, but of course if this can be more the better it is for the prevention of lameness and it will increase their milk yield also
Cows need to be able to find a space to lie down, rest their feet and chew their cud. How much space does a 600-kg Holstein Friesian cow require in a loose housing system like this? Expressed in m2
6 m2 - As a rule of thumb, 1% of her body weight (in kg) expressed in m2 would be a suitable lying space. Others recommend 1m2 per 1,000 litre milk yield, and with yields bordering 10,000 per yer per cow this would be 10m2, per cow, quick maths.
What is, roughly, the required feed space for a cow (in cm)?
60cm - Another rule of thumb: 10% of the body weight (in kg) of the cows, measured as cm feed space. So a 600-kg cow would need 60 cm of feed space. Large ones more, smaller ones (youngstock, Jersey cows) less. Recently calved cows will require more space (80cm) as they are a bit bigger, and also a bit unstable, literally, as well as in their social rank.
What is the most appropriate treatment for a comminuted femoral fracture? And what is the most suitable fixation?
Analgesia - It is very difficult to put a support dressing on a femoral fracture
External skeletal fixation
Tarsal hyperextension is most likely associated with what?
Muscular contracture - tightening of muscles leading to joint stiffness
If this swelling near the calcaneal/Achilles tendon was related to an acute laceration of the tendon the most suitable primary suture for the tendon would be?
Locking loop suture - polydioxanone
You need a non-absorbable suture or an absorbably with a very long strength profile in the wound AND a suitable suture pattern for a tendon where the suture must be looped or laid in such a way as to grip the fibres not pull through them. Usable suture materials: nylon, steel, polydioxanone, usable patterns: locking loop, 3 pulley loop or bunnel.
What drug is most used when doing nerve blocks in horses?
MEPIVACAINE = Na channel blocking LA
When would you perform a Palmar Digital Nerve block?
This is the first nerve block to do with forelimb lameness
Put as close to angular cartilage on back of foot as possible
Anesthetizes - most structures in foot - sole, DIP
What is the second nerve block performed in the distal limb of a horse?
ABAXIAL SESAMOID
Anesthetizes all structures in foot AND PASTERN (including dorsal coronary band region) and unpredictable parts of the fetlock
What is the third nerve block performed in the distal limb of a horse?
Low Palmar (plantar) block (Low 4 point block) Blocks palmar and palmar metacarpal nerves (do both sides = 4 points) - ALL STRUCTURES IN FETLOCK, PASTERN, AND FOOT *done in forelimb and hindlimb*
How might normal joint fluid appear grossly (think color, consistency etc.)?
Small volume of fluid, clear to straw-colored, viscous, fluid should not clot
On a joint fluid analysis with high cellularity dominated by degenerate neutrophils with bacteria present, what is the likely diagnosis?
Septic neutrophilic inflammation (e.g. secondary to penetrating injury/wound)
Degeneration of neutrophils is indicative of swelling of the nucleus
On a joint fluid analysis with high cellularity dominated by non-degenerate neutrophils and low number or macrophages, what is the likely diagnosis?
Immune-mediated polyarthritis - especially if seen in more than one joint - will see shifting lameness in patient
(non-degenerate neutrophils are usually present in non-septic inflammation)
When taking rads for suspected laminitis, why would you use a piece of metal on the front of the hoof?
The keratin of the hoof does not always show up well on the radiograph, so a piece of metal is used to outline the contour of the outer wall of the hoof and to verify if any rotation of the distal phalanx in the hoof capsule has occurred.
What is external coaptation?
The use of casts and bandages to stabilize fractures - want to immobilize the joints ABOVE and BELOW the fracture
(fractures distal to elbow and stifle are MOST ammendable with this)
Ex: Robert Jones bandage used to immobilize joint and modified Robert Jones bandage used to partially immobilize joint
What are common problems when using external coaptation?
Too much or too little bandaging
Too much –> pressure sores, swelling, vascular compromise
Too little –> excessive movement and not stabilization
What are the two most common causes of bilateral pelvic lameness in a horse?
- suspensory ligament desmitis
- sacroiliac pain
What bacteria has to be present to confirm Footrot?
D. Nodusus
Describe quittor in horses.
A chronic, septic condition of one of the collateral cartilages of the distal phalanx characterized by necrosis of the cartilage and one or more sinus tracts extending from the diseased cartilage through the skin in the coronary band region
- Could be caused by trauma, ascending infection from white line, or deep hoof cracks
With rads, how could you tell if the navicular bone was damaged by a FB/penetrating wound?
Put contrast in the navicular bursa and see if any comes out via the nail tract
When attempting to diagnose navicular syndrome, which nerve block would be best to use?
Palmar digital nerve block
True or false: fractures to the distal phalanx can lead to OA in the DIP joint.
TRUE
What are the best NSAIDs to use for laminitis? Opiates?
NSAIDs = flunixin, Phenylbutazone
Can use opiates for short term if these aren’t sufficient
Opiates = morphine, fentanyl
Why is using ice a good choice for laminitis - esp. septic laminitis? What other treatment would you use in this type of laminitis?
Causes vasoconstriction –> less circulation of endotoxins to feet
TREAT UNDERLYING CAUSE - anti-endotoxin therapy
How would ACP help in cases of laminitis?
May encourage them to lay down, taking weight off their feet
What would you see on radiographs with hip dysplasia?
Flat femoral head = mushroom
Flat acetabulum = dishing
Osteophytes, thickened joint capsule
follow lining of femoral head and look to see if it is making good contact/smoothly with the acetabulum
What is the Ortolani test?
With dog in lateral recumbency - Place finger on one hand on greater trochanter of femur and other hand on the stifle - move stifle inwards and then lift up - positive Ortolani –> a drop in the finger = HIP DYSPLASIA
https://www.youtube.com/watch?v=zFbBUMZvPa8
What do radiographs of Legg Calve Perthes look like?
Femoral head has a dark ring of necrosis around it
https://en.wikipedia.org/wiki/Legg–Calvé–Perthes_disease
What is osteomyelitis vs. osteitis?
Osteomyelitis = infection of the cortical bone and medullary cavity Osteitis = infection of the cortex without the involvement of the red or yellow BM
What are the types of inflammatory arthritis?
Immune-mediated (erosive and non-erosive)
Infective
Crystal-Induced
True or false: Both erosive and non-erosive immune-mediated arthritis have radiographic changes of erosion.
FALSE - you will only see obvious radiographic changes with erosive arthritis
Would the glucose levels in a synovial fluid analysis increase or decrease with bacterial infective arthritis?
DECREASE - bacteria would use the glucose present
Normal joint glucose levels > 90
Septic Arthritis < 50
What triggers IMPA?
Abnormal B and T cell interaction - it might initially be a normal response to an antigenic stimulation
But Ag and AB binding to make complexes –> inflammatory products in synovial fluid (neutrophils and macrophages)
Mistakes = body’s immune system fails to recognize the body’s OWN tissue components
The reaction is OVER THE TOP and does not stop (like me complaining about school)
What happens in erosive IMPA?
Chronic synovitis –> production of proliferative granulation tissue (PANNUS!!!!) that invades the articular cartilage and can erode sub-chondral bone
Pannus + inflamed synovium produce enzymes (proteases and collagenases) –> further joint destruction
RARE - only accounts for 1% PA
Can subtype into RA, periosteal proliferative PA - but does not change the treatment plan or outcome
True or false - septic arthritis is usually monoarthopathic.
TRUE - unless a case of hematogenous spread (foal umbilicus, intestine, endocarditis)
True or false - acute septic arthritis is not an emergency in horses.
FALSE - it is an emergency and needs to be treated ASAP as possible
Abx and lavage - can use intra-articular Abx, IV Abx - penicillin and gentamycin, oral abx
Resample joint fluid after 48 hours of treatment
How do glycosaminoglycans (Adequan) work?
MMP (protease) inhibition, stimulate hyaluronic acid production and stimulate matrix synthesis
What is the key inflammatory mediator in osteoarthritis?
IL-1 - stimulates cartilage-degrading enzymes - MMPs, aggrecanase
Can use IRAP - IL-1 Receptor Antagonist Protein = has been a therapeutic success in some cases
What is visco-supplementation for OA?
Intra-articular injection of high molecular-weight sodium hyaluronate- helps to increase elastoviscosity of the synovial fluid
What is the difference between Type A and Type B synoviocytes?
Type a - macrophagic fucntion
Type b - fibroblastic function to produce HA
What are the most likely bacteria to be present in bacterial arthritis?
Staph, Strep (and Pasteurella)
True or false - you should always ask for travel history with suspected arthritis cases.
TRUE - could be borrelial (lyme) arthritis, rickettsial arthritis, protozoal arthritis
How does nuclear scintigraphy work?
Inject a safe amount of radioactive isotope
The body will take up isotope and will be deposited in bone- usually inflamed or remodeling bones - pick up radiation and emit it
Needs to be picked up by a camera and turns it into an image
Can see increased metabolic bone activity - will appear darker
Where do you want to aim the LA when performing a sacroiliac block?
Inside of the aspect of the wing of the ileum
In bone fractures, what forces mainly act on the diaphysis?
All forces (except avulsion, which mainly acts on the epiphysis due to muscle attachment) but BENDING FORCES especially
What fracture implant best neutralises forces?
external skeletal fixator
What fracture implant allows bridging of bone ends and healing via callus formation?
Plates and screws
What are the two main outcomes of poor fracture healing?
Malalignment and non-union
After repairing a fracture when do you take rads? What are you trying to monitor?
take after surgery and 6w after.
Look at bone apposition, alignment, whether the apparatus is interfering with bone healing and bone activity (is the bone healing physiologically well? It won’t if there is osteosarcoma, sepsis, hyperparathyroidism..)
What animals usually presents with epiphysial fractures?
Pups!!!
Why are epiphysial repairs so tricky in pups?
Because fractures and interventions can damage the physis -> bones will stop growing -> deformity
What special precautions do you take when repairing bones at the site of muscle attachment?
Put some pins and wires to neutralize avulsion forces
T or F: a femoral head fracture is tricky to fix because of bending forces applied while the animal is standing
Falseee!!
Bending forces at the end of long bones are minimal. a femoral head fracture can be stabilized with just some intracapsular pins +/- wires
T or F: when dealing with fractures near a joint you want to always heal them by primary intention (bone apposition)
True! You don’t want a callus (second intention healing) near a joint as it will immobilize it
What is the effect of synovial fluid on fracture healing?
It will delay healing
T or F: it’s very important that fracture repairs in horses allow the animal to stand on both the broken and the healthy leg
True. If weight constantly on healthy leg -> laminitis
What kind of implant would you choose for very comminuted fractures?
The implant must take all the load
What are some options to fix interdigitating transverse fractures?
These fractures can be reduced (put together) easily, therefore you can do:
- external coaptation (only if distal to elbow/stifle)
- repair with an external fixator
- repair with plates and screws (allows for better compression of bone fracture)
On what joints is arthodesis most commonly performed?
carpus and tarsus.
Arthodesis= irreversible fusion of the joint
What kind of fractures are suitable for external coaptation?
- interdigitating comminuted fractures (transverse best) MINIMALLY DISPLACED
- there must be at least 50% overlap of fracture ends on orthogonal rads
- must be distal to elbow/stifle
- ideal if there is internal splinting (the other paired bone is intact)
- ideal if the patient is young
When should you avoid external coaptation?
- distal fractures in toy breeds (not enough blood supply for healing)
- articular fractures
- if cannot be immobilized above and below fracture line
- obese patients
- chondrodystrophic breeds
T or F: tramadol is a good analgesic for OA
False you biiiish
weak opioid, all it does is sedate the animal
On rads, what are two pathologies that present with: regional osteolysis, osteophytes, periosteal reaction?
Osteosarcoma and osteomyelitis.
Cysts may look similar but the osteolytic region is well defined by margins
Only way to differentiate is with FNA
What feature helps you distinguish osteosarcoma from other joint tumors?
Osteosarcomas are monostotic -> they don’t cross the joint, they affect the bone on only one side
Joint tumors cross the joint and both bones on either side will be affected
What is lung digit syndrome?
It’s a condition in cats. Basically when lung neoplasia spreads to the digits. Often gets picked up because the cat becomes lame.
Prognosis is very poor
What is the prognosis for osteomyelitis?
Guarded.
Antibiotics don’t penetrate well and tends to recur and flare up frequently. can lead to loads of pain and pathological fractures
What cancers commonly spread to bones?
Mammary tumors
Prostatic carcinomas
Multiple myeloma
Lymphoma
What is the best chemo protocol for osteosarcoma?
Carboplatin containing protocol
Describe treatment progression for managing osteoarthitis
1) Controlled exercise and weight loss
2) Physiotherapy
3) Pharmacological management
4) Surgery (arthroplasty, arthrodesis, amputation)
You need to switch NSAIDs, what do you do before starting the new drug?
Must wait a 7d WASHOUT period
In managing osteoarthitis, what interventions have been proven to be beneficial?
1) NSAIDs (4-6 w course then taper down for long term management)
2) Amantadine (for patients that can’t receive NSAIDs, works on NMDA receptors)
3) Omega 3
4) Galliprant (inhibit PGE2 binding and very safe)
5) Antinerve GF antibodies - Ranevetmab-(reduce sensitivity to pain, very safe)
6) Home modifications
7) short, frequent exercise
8) Hydrotherapy > physio
9) WEIGHT LOSS
In managing osteoarthitis, what interventions may be beneficial?
- glycosaminoglycans and chondroitin sulfate (nautriceutical, won’t harm, must treat for at least 70d)
- corticosteroids (absolutely don’t combine with NSAIDs, higher risk of inflammation when injected in the joint, they are toxic to chondrocytes)
- intra-articular botox injection (inhibits release of Substance P from nerves -> reduced nociception)
- gabapentin (mainly used in nerve root pain, takes several weeks to take effect)
- paracetamol
- hyaluronic acid intraarticular injection
In managing osteoarthitis, what interventions are worth trying?
- green lipped muscles (rich in AA, GAG, omega 3, vitamins.. but need to supplement for at least 2 mo)
- platelet rich plasma
- stem cell therapy
- cannabid oil (works on endocannabinoid receptors and reduces pain)
Causes of arthralgia?
1) Osteoarthitis (primary or secondary)
2) Neoplasia -> affects one joint
3) Trauma -> one joint
4) Inflammatory (immune and infectious) -> if it affects multiple joints probably immune mediated!!
5) Coagulopathic
What joints are often painful in animals with IMPA?
Carpi and tarsi
Why is it recommended to do urinalysis when suspecting IMPA?
UTI is one of the most common causes of reactive IMPA
Arthocentesis and synovial fluid analysis should be carried out to investigate painful joints. How do you distinguish IMPA from septic arthitis?
Both have high neutrophils, lower viscosity, look more opaque, have higher protein,
septic PA will have lower glucose and higher lactate
What are the differences when managing septic arthitis in SA vs horses?
Horses require much more aggressive treatment:
- joint lavage
- intrarticular antibiotic
- systemic antibiotics (both IV and oral)
Only 80% of horses will recover, 50% can resume competitions
What other lesions do dogs with SLE present with other than arthralgia?
crusty, ulcerated, depegmented nasal planum, footpad ulceration, proteinuria, pyrexia
What is Felty’s syndrome?
Reumathoid arthitis + splenomegaly + neutropenia in greyhounds
What is the main diagnostic test to help diagnose RA?
RADS
Can IMPA be cured?
Cure with immunosuppressive therapy is achieved in about half of the patients. 0% of patients with erosive polyarthritis will be cured
What’s a marker of DJD in horses?
PGE2
Synoviocytes release prostaglandins and other mediators to signal chondrocytes to make PGE2
What’s the treatment for DDFT tear?
Navicular Bursoscopy + debridement of tear
Which P3 fractures require surgical treatment with lag screw placement?
2 and 3
What therapeutic farriery intervention is needed in general for P3 fractures?
bar shoes
Basically they increase the contact area. However these should increase strain on DDFT
What farriery interventions decrease the strain on DDFT?
- setting the shoeback (trimming toe region)
- elevating the heel
- rockering toe
these interventions facilitate the breakover point -> which is initiated by the DDFT
What farriery intervention is important in patients with OA?
Absorbing pads
What farriery intervention is important in patients with foot abscesses?
Medicated plates
What farriery intervention is important in patients with laminitis?
- trimming toe -> facilitate breakover point
- wedge on the healthy side -> shifts pressure to healthy side and takes pressure off the painful side
- shows can be glued (instead of fixed with nails)
What farriery intervention is important in patients with Suspensory ligament injury?
shoes with wide toe and thin branches
this increases strain on the DDFT and decreases strain on SDFT and SL
What farriery intervention is important in patients with Navicular bone injury?
Bar shoes
How does lamenesses involving SDFT and DDFT differ?
SDFT lameness is temporary, and flares up at different times. Also it gets worse on softer ground
DDFT lameness is constant
Horse presents with elevated toe. What’s the most likely cause?
DDFT rupture
Horse presents with dropped fetlock. What’s the most likely cause?
SL inflammation
