Equine Flashcards
Bone Spavin
DJD of the hock (tibiotarsal joint) terminating in the formation of exostoses (cartilaginous outgrowths on bone) and akylosis (abnormal stiffening) of the joint
Bucked shins
Front limb lameness in young (2-3y) thoroughbred or racing QH.
Aka metacarpal periostitis
Metacarpal bone painful on manual compression
Likely due to microfractures in bone from compression due to intense exercise
Bog Spavin
Chronic synovitis in the hock (tibiotarsal jiont) causing obvious distension of joint capsule.
what clin path things do you look for on bloodwork that indicates a muscle injury?
creatinine kinase (CK) aspartate aminotransferase (AST)
Exertional rhabdomyolysis
CS
tx
"tying up" muscle necrosis related to exertion high Crt, CK, AST myoglobinuria Tx: rest, NSAIDs, fluids, dantrolene sodium and methocarbamol
post anesthesic myopathy
CS
tx
localized painful, swollen muscle non-weight bearing on affected limbs increased HR and RR increased CK and AST and myoglobinuria tx: same as exertional rhabdomyolysis
how many joint spaces are in the carpus, stifle and hock
carpus and stifle: 3
hock: 4
which joint spaces communicate in the stifle ?
bottom two: the intermediate carpal joint and carpal-metacarpal joint
which joints comunicate in the hock?
top two: tarsocrual joint and proximal intertarsal joint
polysaccharide storage myopathy seen in what breeds? pathophys CS Dx management
quarterhorses, warmbloods and draft breeds
muscle cannot generate enough energy so they uptake glucose and insulin creating enzyme imbalance and increased synthesis of less branched glycogen
dx: muscle biopsy - (+) for PAS (polysaccharide storage myopathy)
management: consistent exrcise, diet low in carbs and sugar, decrease grass hay
what joint spaces communicate in the stifle?
the femorpatellar joint and hte medial femuro-tibial jiont
recurrent exertional rhabdo
seen in what breeds?
Dx
management
seen in thoroughbreds
dx: muscle biopsy - increased # of central nuclei
management: like polysaccharide storage myopathy - consistent exercise; diet low in carbs and sugar and low in grass hay
where does the DDF insert?
palmar side of P3
where does the suspensory ligament originate and insert?
O: from mid cannon (MC3)
I: onto the dorsal digital extensor ligament at the level of P2
where does the SDF insert?
into the DDF at the level of the pastern joint (P1 & P2)
annular ligament - where the heck is it?
runs laterally like a bracelet just proximal to the fetlock (metacarpal-phalangeal joint)
proximal digital annular joint - where is it?
crosses like an “X” on the palmar side of the fetlock joint
hyperkalemic periodic paralysis seen in what breed? CS Dx Tx and management
quarterhorses - autosomal DOMINANT
mutation of Na channels –> hyperexcitable muscles
CS: muscle fasciulations, prolapse of third eyelid, facial muscle spasm
dx: DNA blood or hair test (HH - definitely have it, NH - carriers)
Tx: decrease K levels in plasma. mild: give karyo syrup and grain. severe: give IV bicarb, dextrose, Ca gluconate and insulin
management: diet low in K (no alfalfa, bran or molasses), regular exercise, acetazolamide (increases K excretion in urine)
white muscle disease - nutritional myodegeneration - nutritional muscular dystrophy
CS
non-inflammaotry degenerative disease of skeletal muscle and cardiac m.
caused by deficiency in Vit. E & Selenium
CS has 3 forms:
cardiac form: seen in foals - acute onset of cardiac decompnesation (heart murmurs, pulmonary edema, dyspnea)
subacute skeletal form: foals - weakness, stiff and spastic gait, tense and painful muscles, dysphagia
chronic myopathy: ADULT horses - masseter atrophy and degeneration - dysphagia, inability to eat, etc.
white muscle disease - dx and tx
Dx: incrased CK, AS, low Se and glutathione
Tx: Vit E/Se injections, oral supplementation
clostridial myonecrosis
agent
pathophys
how to tell the difference between clostridial myonecrosis vs injection site abscess
agent: C. perfringens Type A
occurs most commonly due to injections
will see gram (+) rods and will have anaerobic culture
clostridial myonecrosis
CS
Tx
CS: rapid onset of severe local swelling, heat, pain and crepitus, high fever and tachycardia –> severe toxemia, shock and death
tx: penicillin - double dose every 4 - 6 hours, supportive care, debridement and fasciotomy
how do you diagnose septic arthritis?
if TP > 2.5 and WBC > 20,000
what are the 4 most common locations for osteochondrosis in horses?
“DIRT” - distal intermediate ridge of tibia - in hock
lateral trochlear ridge of femur (cartilage flap)
medial condyle of femur (bone cyst)
fetlock - medial condylar ridge
a flexural deformity of the fetlock and pastern involves what tendon and how is it treated?
SDF only
tx: immoblize by splinting to allow tendons to relax can give oxytetracycline if foal <1 week
a flexural deformity of the coffin joint leads to what? what is it caused by and how is it treated?
deformity of coffin joint leads to club foot.
treated by keeping toe long and adding extensions
sx: cut inferior check ligament
in severe cases can cut DDF but this is considered a salvage procedure only done in young foals <1 year
valgus is a what deformity? how is it treated?
lateral deformity
shorten lateral wall and place medial extensions (place extension on side you want foot to grow!)
varus is a what deformity? how is it treated?
medial deformity
shorten medial wall and place lateral extensions
what is sweeny?
inflammation of suprascapular nerve secondary to trauma of shoulder. common in driving horses
tx = surgical release
fistulous withers - 3 causes
brucella abortis
fractured spinous process of thoracic vertebra
penetrating trauma
what is a slab fracture?
fracture of the 3rd carpal bone
bucked shins
inflammation/stress re-modeling of dorsal MC3 (cannon bone)
splints
tx
bony exostosis (growth) of MC 2 & 4; traumatic may have secondary suspensory desmitis
tx: NSAIDs, rest, neglect
breakdown injury
tx
disruption of suspensory apparatus (suspensory ligament, sesamoid bone, distal sesamoid ligament)
tx w/ arthrodesis of fetlock
navicular disease
CS
tx
degenerative disease
CS: switching leg lameness after palmar digital n. block
dx = MRI gold standard
Tx: rest, NSAIDs shoeing (egg bar shoe)
canker
tx
proliferative pododermatitis
hypertrophy of horn-producing tissues of foot; most common in hindlimbs
- looks like hairy growth around frog
tx = debride and topical abx
sidebones
ossification of collateral cartilages of P3
quittor
tx
necrosis of collateral cartilages - most common in forelimb
often happens due to injury near caudal coronary band
tx: surgical excision
keratoma
tumor that develops in deep aspect of hoof wal
foot abscess
subsolar abscess
most common cause of non-weight bearing illness
dx = hoof testers, +/- blocks, rads
tx = pare out with hoof knife, daily soaking and bandaging (no systemic abx!)
street nail
dx
tx
px
can cause septic pedal osteitis and septic bursitis, non-weight baring, can be serious
dx: rads, arthrocentesis (bursal fluid = increased protein & WBC)
tx: arthroscopy, hospital plate
px: guarded
seedy toe
tx
change in character of the horn such that the inner surface is crumbly and there may be a cavity due to lack of substance. will hear a hollow sound when tapped
tx like absces
sheared heels
tx
asymmetry of heels due to imbalance resulting in one part of hte heel to hit the ground before the other. results in asymmetrical growth.
tx w/ repeated trimmings
ringbone
tx
OA of the phalanges.
tx w/ arthrodesis
stringhalt
tx
involuntary FLEXION of the hindlimb, usually bilateral.
tx w/ lateral digital etensor tenectomy
jack spavin
cunean bursitis, irritation of cunean tendon as a result of bone growth on medial hock
thoroughpin
effusion of tarsal sheath (sheath of DDF)
suspensory desmitis - forelimb vs hindlimb
forelimb - Tx = medical; good px
hindlimb - tx = surgical; poor px
septic navicular bursa - common cause?
usually nail puncture - ALWAYS an emergency!!
