Equine Lameness - Overview Flashcards
what are some common presentations of a lame horse?
subtle changes in weight-distribution during gait, non-weight bearing lameness that causes severe distress, & severe mechanical lameness without pain
what are some differentials for traumatic causes of lameness in horses?
fracture, soft tissue injury, laminitis, foreign body, bruised sole/heel, muscle strain, hygroma, & OA
what are some differentials for congenital causes of lameness in horses?
OCD & angluar limb deformity
what are some differentials for infectious causes of lameness in horses?
foot abscess, septic joint/tendon sheath/bursa, cellulitis, white line disease/thrush/quittor/canker, & lyme disease
what are some differentials for metabolic causes of lameness in horses?
laminitis & myopathy
what are some differentials for mechanical causes of lameness in horses?
stringhalt, fibrotic myopathy, & intermittent upward fixation of patella/delayed patellar release
what are some differentials for circulatory/other causes of lameness in horses?
laminitis, navicular syndrome, improper hoof balance/shoeing (especially on top of poor confirmation), silicosis, OA, & keratoma
what are the very important questions you need to ask when taking a history on a lame horse?
duration, onset (sudden vs gradual), any previous lameness or recent illness, treatments/management of lameness & results, level of work the horse does, last shoeing/trim, & what exacerbates the lameness
what are the different grades of the AAEP lameness scale?
grade 1: only perceptible under certain conditions, grade 2: consistently perceptible under certain circumstances, grade 3: consistently perceptible in a straight line & circle at a trot, grade 4: consistently perceptible at a walk, & grade 5: non-weight bearing
how do you need to exam a lame horse to assign a lameness score?
observe the horse moving from the front/side/behind at a walk, trot, & canter both on a straight line +/- lunge line, on a hard & soft surface, in hand or under saddle
what are some signs seen on physical exam of a horse that is lame on its forelimbs?
down on sound - head bobs up when lame limb hits the ground & goes down when the sound leg hits the ground
what are some signs seen on physical exam of a horse that is lame on its hindlimbs?
more difficult to assess - sacrum/pelvis hikes up or moves more when the lame limb hits the ground - can get contralateral head bob with severe hind limb lameness
what should you palpate on a lame horse during your physical exam?
limbs, joints, soft tissues, neck, back, & musculature - look for heat, pain, swelling, effusion - compare with contralateral limb
what should you look to observe on a lame horse during your physical exam?
muscular asymmetries, stride length (often shorter in lame limb), wounds/scars, stance at rest, & wear on hooves.shoes & hoof confirmation
what is the purpose of doing flexions on a lame horse? where do you perform them on the horse?
localize source of lameness - distal forelimbs, carpus, +/- shoulder, distal hindlimbs, hock/entire limb, stifle - make sure to use consistent pressure & duration
what is the purpose of using hoof testers on a lame horse? where do you check the foot with the hoof testers?
help localize any foot soreness - toes, quarters, & across heel/frog
when should you use extreme caution & not force a lame horse to move/exercise during a lameness exam?
lamesness is severe or a fracture is suspected - do not use regional blocks, making them walk on the limb can worsen the injury, & a closed fracture can become an open fracture
how long does lidocaine work for regional anesthesia for a lameness exam? what about mepivacaine? bupivacaine?
lidocaine: 30-45 minutes, mepivacaine: 90-120 minutes, & bupivacaine: 4-6 hours
if a lameness disappears after a nerve block, what does that indicate?
the problem causing the lameness is at or distal to the location of that injection
you always should start local blocks distally & move proximally when working up a lame horse except in the case of what?
if you suspect a specific joint based on the exam!!!
90% of all equine lameness is localized to what?
the foot!!!!!
when are rads the best diagnostic option for a lame horse? what is required for good images?
best for bone lesions, & can be performed in clinic or in the field - good images require proper positioning and at least 2 views in 2 planes - can use contralateral limb to compare if needed
when is ultrasound the best diagnostic tool for a lame horse?
best for soft tissue, some bone lesions, & wound evaluation - can perform in the field or in a clinic, diagnostic utility correlates with user experience, & can compare contralateral limb if needed
when is nuclear scintigraphy the best diagnostic for a lame horse?
best for bone lesions - useful when lameness can’t be localized or there are multiple lame limbs - requires referral & a hospital stay
when is an MRI the best diagnostic for a lame horse?
best for soft tissue but also used for bone - requires referral & sedation/general anesthesia
when is a CT the best diagnostic option for a lame horse?
best for bone lesions, but contrast can be used to enhance soft tissue lesions - requires referral & sedation/general anesthesia
what are some medications used for joint injections?
steroids, hyaluronic acids, & autolgous therapies such as platelet-rich plasma, stem cells, sarapin, & interleukin-1 receptor antagonist protein
what NSAIDS are often used to treat lame horses?
phenylbutazone, flunixin meglumine, & firocoxib
what is the purpose of using methocarbamol for a lame horse?
muscle relaxer
what is the benefit of using shock wave therapy for a lame horse?
increases healing, decreases pain & inflammation, increases neovascularization, & increases osteogenesis
what are some adjunctive therapies used for lame horses?
massage, chiropractics, & acupuncture
if a lame horse presents with multifocal neuro signs & asymmetric muscle atrophy- what do you suspect?
EPM
