Equine Foot Flashcards
what is a hoof abscess?
focal accumulation of purulent exudate that most often occurs between germinal and keratinized epithelium; also known as septic pododermatitis
describe the etiology/pathophysiology of hoof abscess?
etiology: bacterial invasion through keratinized epithelium via
- defects in hoof wall lead to microcracks and white line separation or
- traumatic damage from foreign body penetration or sole bruising
- environmental factors: moisture and moisture inconsistency (drought to sudden rain, etc).
- predispositons: laminitis, poor hoof structures
pathogenesis:
1. rapid increase in pressure causes
2. separation from germinal layer of epithelium (subsolar, subcuneal, submural) and involvement of deeper structures
what is the clinical presentation of a hoof abscess?
- acute severe lameness (top differential for this plus fractures)
- variable lameness with duration and extent of abscess
what are 5 differential diagnoses for hoof asbcess?
- coffin bone fracture
- navicular bone fracture
- sepsis of deeper structures
- severe bruising
- severe soft tissue injury
describe diagnosis of hoof abscess
- physical exam:
-increased digital pulses
-increased hoof capsule pressure
-coronary band/heel bulb will be swelling, painful to touch, have purulent discharge
-hoof tester response - visual exam of solar surfaceL look for dark discoloration and further eval that area but avoid excessive pairing (hole making)
- radiographs: usually not on first visit; if still can’t find draining tract on second visit, do a radiograph and look for dark spot
describe treatment/management of hoof abscess
- facilitate drainage: make sure hole you make is big enough to allow drainage
- foot bandage: keep area soft after drain to prevent sealing back up before all infection is drained or will reabscess
- pain management: some type of NSAID (phenylbutazone is most effective; make horse more comfortable, bear more weight on affected foot, push infection out of capsule)
- antibiotics: not generally use systemic antibiotics bc concentrations really can’t reach affected tissue; but if involvement of deeper structures (infection migrated to cause septic area of coffin bone may use Ab; region limb perfusion
- tetanus prophylaxis: boost!
describe prognosis for hoof abscess
- uncomplicated: good
- deeper structure involvement: depends on affected structure but generally if can establish drainage within 3 days generally good
what is white line disease?
keratoyltic condition that affects deeper layers of stratum medium of hoof wall, causing crumbling decomposition of the horn at the white line and can lead to separation of the hoof wall
describe the etiology/pathophysiology of white line disease
- unknown agent, but suspect involvement of fungi or anaerobic bacteria that causes a keratolytic process that creates cavities within the hoof wall
- can have single OR multiple hoof wall, so examine all 4 hooves
- inflammation of underlying tissues is uncommon
- coffin bone displacement is possible but also uncommon
- can be an incidental finding/asymptomatic; the lameness observed is due to debris in the created cavity putting pressure on sensitive lamellae or coffin bone displacement
describe differential diagnoses for white line disease
- laminitis
- abscess
describe diagnosis of white line disease
- soft and chalky horn
- can use hoof wall percussion (tap around and see if can hear a hollow spot)
- radiographs!!
describe treatment/management of white line disease
- removal of undermine hoof wall
- hoof wall capsule stabilization: after removal of hoof wall, don’t want to cover area bc want to expose to air, so stabilize by boot or other creative means; exposure to oxygen is key!
- topical medications
describe prognosis of white line disease
- return to previous performance if coffin bone not displaced
- time to return is dependent on extent of hoof wall resected and growth rate of hoof wall (average horse takes about a year to grow from coronary band to ground)
- recurrence is uncommon: usually owners on alert after diagnosis and better care following
what are hoof cracks?
vertical or horizontal fissures in the hoof wall
describe etiology/pathophysiology of hoof cracks
1, causes by excessive forces on hoof wall/coronary band
- classified by:
-orientation
-location
-depth
-length - predisposing factors:
-hoof wall imbalance
-coronary band trauma/defect
-poor quality hoof wall
-inadequate/infrequent trimming
describe clinical presentation of hoof cracks
- visual exam- clients notice these
- could present with lameness if unstable or infected full-thickness crack