Equine Lameness - Top 6 Lameness Causes Flashcards
what is the classic case presentation of a horse with a subsolar abscess?
variable lameness (1-5), heat in hoof, increased digital pulse, +/- breaks at coronary band instead of sole, +/- sensitive site on coronary band & non-specific hoof tester sensitivity
what are some possible etiologies causing a subsolar abscess in a horse?
poor hoof quality, laminitis, bruises, nails. wet/dry footing, poor conformation, & idiopathic
how is a subsolar abscess diagnosed?
hoof testers to pinpoint location +/- rads
how is a subsolar abscess treated?
variable depending on vet, severity, & site - palmar digital nerve block prior to probing/lavaging, soak/poultice the hoof & let abscess drain on its own, or open up abscess with hoof knife, keep foot protected until abscess pocket has healed, tetanus immunization, pull shoe, & NSAIDS (rarely systemic antibiotics)
why are subsolar abscesses in horses so painful?
abscess puts pressure on surrounding tissues & there is no room for expansion within the rigid hoof capsule
what is the classic case presentation of a horse with acute laminitis?
before mechanical failure (breakdown of laminar connection between coffin bone & hoof wall) very lame
what is the classic case presentation of a horse with subacute laminitis?
occurs after the acute phase but without mechanical failure
what is the classic case presentation of a horse with chronic laminitis?
happens when there is mechanical failure
what is laminitis specific grading?
obel grades 1-4, grade 1: alternately lifting feet, not lame at a walk, grade 2: stiff & resists turning at the walk & lame at the trot, grade 3: lame at the walk, stilted gait, & resists lifting feet, & grade 4: will not move unless forced
what are the clinical signs of a classic mild case of laminitis?
mild reluctance to move, short strided gait, increased digital pulses, & mild weight-shifting
what are the clinical signs of a classic severe case of laminitis?
will not move, sweating/painful, shifting weight between limbs & from front to hind limbs, can’t pick up one foot at a time, +/- recumbency
what are some endocrine related causes of laminitis?
pasture associated laminitis - equine metabolic syndrome from insulin dysregulation & equine cushings
apart from endocrine related causes, what are some other etiologies that can cause laminitis?
inflammation/SIRS (retained placenta, colitis, grain overload), support limb laminitis from non-weight bearing contralateral limb, & repeated trauma on a hard surface
why are further diagnostics needed even when laminitis is often obvious from clinical signs?
needed to gauge prognosis & gauge treatment
what do you expect from hoof testers on a horse with laminitis?
especially positive over the toe
why evaluate the hoof capsule of a horse with laminitis?
rings are a sign of chronicity
why palpate the coronary band of a horse with laminitis?
feel for an abnormal ledge as it is a sign of a sinking p3
what is seen on rads from a horse with laminitis?
thickening of dorsal hoof-lamellar zone, rotation or sinking of p3 with respect to the hoof wall, & remodeling of dorsodistal p3
when is contrast venography used for laminitis cases?
useful for prognosis & for help directing treatment - requires experience to interpret
what does treatment of laminitis depend on?
severity, cause, conformation, & finances
what are the mainstays of treatment for laminitis?
anti-inflammatories, cryotherapy, analgesics, & hoof/frog support (lily pads, special shoes, padded boots)
what does the prognosis of laminitis depend on?
sevreity, time to diagnosis, & cause
what can treatment of laminitis range from?
short period of rest to shoeing/management changes to euthanasia
what is the classic case presentation of a horse with degenerative joint disease?
usually older horses with joint effusion, variable lameness, heat over the joint, & +/- decreased joint motion
how is degenerative joint disease diagnosed after the lameness has been localized with the exam, flexions, regional blocks?
rads - osteophytes, decreased joint space, bone sclerosis, & effusion, ultrasound - cartilage/soft tissue damage, degree of effusion, & synovial proliferation
what does the treatment of degenerative joint disease depend on?
severity, joint involved, age, etiology, use of the horse, & finances
what is the purpose of arthroscopy of a degenerative joint in a horse?
to evaluate & clean up the joint
when is arthrodesis an option for treatment of degenerative joint disease in a horse?
surgical option for low motion joints such as the pastern & lower hock joints
what is the pathogenesis of degenerative joint disease in horses?
cartilage & soft tissue damage in a joint causes instability & inflammation which results in further joint damage
what does the prognosis of degenerative joint disease depend on?
prior mentioned factors for treatment, some can be managed with treatment, and some horses get retired or get a new job
what is wind puffs?
metacarpophalangeal & metatarsophalangeal joints - effusion
what is thoroughpin?
tarsal sheath of DDFT proximal to the tarsus is injured
what is bog spavin?
OA of the tibiotarsal joint
what horses often have soft tissue injuries?
sport horses - any tendon, ligament, or joint capsule can be injured (strained vs torn, acute vs chronic, & mild vs severe)
what are acute signs of a soft tissue injury in a horse?
heat, pain, lameness, & swelling of injured tissue
what are chronic signs of a soft tissue injury in a horse?
mild thickening of injured tissue, pain on palpation, & mild to severe lameness
what is seen on ultrasound of a soft tissue injury on a horse? how is ultrasound used for monitoring?
disruption of fibers, edema, hematomas - used to monitor progression, response to treatment, & when the horse can return to work
what does treatment of soft tissue injuries depend on? what are some general treatments used?
severity, tissue involved, age, cause, use, & finances
what soft tissue structure is injured in a horse with bowed tendons?
SDFT
what soft tissue structure is injured in a horse with chronic navicular disease?
DDFT can rupture with this condition
what soft tissue structure is injured in a horse with a breakdown injury?
suspensory ligament - associated with sesamoid fractures in race horses
what soft tissue structures are usually injured in a horse with issues in the distal pastern?
straight, distal, & oblique distal sesamoidean ligaments
what soft tissue structures are usually injured in a horse with stifle problems?
ligaments & meniscae of the stifle (cruciates, femoropatellar, & femorotibial)
what is the classic case presentation of navicular syndrome?
very common in forelimbs & in quarter horses, often seen in horses over 8 years old, slow often insidious onset, & often bilateral forelimb lameness
how is navicular syndrome diagnosed?
blocks to palmar digital, +/- sensitive to digital palpation between heel bulbs, hoof testers on frog, & lower limb flexion
what is seen on rads of a hrose with navicular syndrome?
enlarged navicular synovial invaginations, navicular flexor surface sclerosis or medullary cavity sclerosis, & navicular enthesiophyte formation/calcification
how is navicular syndrome treated?
managed, not fixed - hoof care to decrease pressure on the bone by trimming/shoeing to improve the hoof-pastern angle, shortening the toe +/- raising the heel, egg bar shoes, NSAIDS
what is the salvage procedure used for navicular syndrome?
palmar digital neurectomy - rick of rupturing the DDFT
what is the prognosis for a horse with navicular syndrome?
guarded - most cases progress with time
T/F: the etiology behind navicular syndrome is very cimplicated & involves hereditary, conformational, & vascular components
TRUE
T/F: degree of change on radiographs does NOT equal degree of lameness
TRUE
what bones are most commonly fractured in horses?
forelimb splint bones, hindlimb splint bones, forelimb & hindlimb cannon bones, distal tarsals, stifle, distal phalanx, elbows, carpals, & first/second phalanx
what does severity of a fracture depend on?
open vs closed, complete vs incomplete, simple vs comminuted, displaced vs non-displaced, life-threatening vs manageable, location, acute vs chronic, lameness score, calm horse vs shocky horse, & minimal swelling vs severe swelling/hematoma
how is a fracture in a horse COMPLETELY diagnosed?
physical exam, rads, +/- ultrasound/nuclear scintigraphy/mri/ct
what do you need to know to be able to treat a fracture in a horse?
type of fracture, how to stabilize it, & prognosis for fracture type/location
T/F: fractures of the humerus, femur, or pelvis in adult horses often cannot be repaired
TRUE
what are some surgical options for fracture repair in a horse?
internal fixation (screws, plates), external fixation, pin casts, foot casts for p3 fractures, & rest/management
T/F: distal limb fractures are often repaired surgically in horses
TRUE
T/F: each fracture location has a different type of therapy depending on the age, size, & temperament of the horse & includes bandaging/stabilization, treatment options, & potential outcomes
TRUE
what is the most common long bone fracture in horses?
diaphyseal 3rd metacarpal bone - cannon bone
