Conditions of the Equine Foot Flashcards
What is the white line?
The junction between the sole and inner hoof wall
What are the 4 signs of inflammation within the equine hoof?
- Heat
- Digital pulses
- DIP joint effusion
- Pastern oedema
What is nail prick and nail bind?
Nail prick - nail of shoe gone through laminae
Nail bind - nail of shoe too close to laminae
How do hoof cracks form and how can we treat them?
Mixture of poor horn quality, thin hoof wall and abnormal hoof angle
Suture/staple or apply a plate - prevent crack from splaying when loaded
What is club foot?
Upright hoof/raised heel
What is a keratoma?
Benign growth of hoof horn
Usually in the dorsal wall due to irritation or abscess
Cause pressure inside the hoof which can lead to pedal bone lysis, may need to removed the abnormal tissue
What are thrush and canker?
Thrush - infection of the frog –> necrosis
Canker - deeper infection of frog and heel, see pus, pungent odour and bleeding –> disintegration of intertubular horn
What is white line disease and how do we manage it?
Loss of bond between hoof wall and sole becomes colonised with bacteria and fungi, often secondary to laminitis or poor hoof quality
Management: Debride all necrotic tissue and diseased horn Disinfect environment Bandage to protect laminae Hardening solutions e.g. forulin
What is a hoof abscess and how are they causes?
Infection of the laminae
- Nail too close
- Penetrating foreign body
- Sole bruise
What is quittor?
Infection of collateral cartilage
Name 2 causes of a black line in the navicular bone on radiography…
- Fracture - could screw together, generally good prognosis but may get OA
- Bipartite navicular bone - congenital abnormality where there were 2 centres of ossiciation
Which structure could be involved in navicular syndrome and what is the typical clinical sign?
Navicular bone Navicular bursa DDFT DIP joint Collateral ligament of DIP joint
Toe first gait (reducing weight on heel)
Usually bilateral lameness
Responds to PD nerve block
What are the 6 types of fractures of the distal phalanx in the horse and how would you treat them?
- Wing (non-articular)
Hoof cast, bar shoe ± lag screw
6m box rest - Wing (articular)
As above - Sagittal (migline)
Lag screw, bar shoe
3-12m box rest - Extensor process
Distinguish from occasional separate centre of ossification often displaced by extensor tendon
Remove fragment
3-6m box rest - Comminuted
Transfixation cast or euthanasia depending on severity
4-6m box rest - Solar margin
Bar shoe
6m box rest
What is the main complication of any fracture of the distal phalanx and how do we treat it?
DIP OA
Intraarticular sodium hyaluronate or steriods
NSAIDs
Corrective farriery
How do you distinguish pedal osteitis and keratoma in the horse?
Pedal osteitis - chronic inflammation of the laminae leads to bone resorption, increased vascular pattern
Keratoma - thickening of hoof wall leads to compression and lysis of the pedal bone
What are the problems associated with disease inside the horse hoof?
Inflammation cannot go anywhere - increases pressure within hoof causing more damage
Difficult to examine
Difficult to relate pain to specific structures
What are the typical clinical signs of laminitis?
Resting with weight on heels, leaning back as the laminae at the front of the hoof are painful
Lameness affecting 2 or more limbs
Bounding digital pulse
Increased hoof temperature
Pain with hoof testers at the point of the frog
Palpable depression at the coronary band
How would you prepare the equine foot for radiography?
Remove any dirt or stones
Remove loose horn
Place marker on dorsal hoof wall
Remove shoes if obscuring region of interest
Pack grooves with Play-Doh
What radiographic view is best for:
a. Extensor process
b. Sole
3. Navicular bone
a. Lateromedial
b. Dorso-60-proximal palmarodistal oblique
c. Dorso-60-proximal palmarodistal oblique for articular surface, palmaro-45-proximal palmarodistal oblique for flexor surface (skyline view)
What is a crena?
Notch or cleft in the solar margin of the pedal bone
What are the 6 radiography signs of laminitis?
1) Dorsal hoof wall and dorsal distal phalanx not parallel, if angle >15º poorer prognosis
2) Distance between coronary band and extensor process of distal phalanx (founder distance) >13mm indicates sinking
3) Dorsal hoof wall thickness >3cm indicates chronic laminitis
4) Lucent line in dorsal hoof wall
5) Lucent line at coronet (sinking)
6) Remodelling or fracture of solar margin (chronic)
What is the difference between an osteophyte and entheseophyte?
Osteophyte - projection into joint space
Entheseophyte - projection at site of ligament or tendon attachment
What are the radiographic signs of navicular disease?
1) Entheseophyte formation
2) Loss of corticomedullary junction (sclerosis)
3) Flexor cortex erosions (lucency)
4) Abnormal distal border (fossae or fractures)
What are the risk factors for laminitis?
1) Sepsis / systemic inflammation
- Can arise from GI disease, pneumonia, septic metritis
2) Endocrine disease
PPID, EMS
3) Mechanical overload
4) Access to pasture, particularly new grass (carbohydrate overload → systemic inflammation)
5) Ponies
6) Female
7) Age
8) Obesity
How can inflammation lead to laminitis?
Dysregulation of epithelial adhesion molecules (hemidesmosomes)
MMP activation (protease enzymes)
Which group of animals are most at risk of pasture associated laminitis?
Obese
EMS
Summer pastures contains more carbohydrates exaggerating insulin resistance
What is the treatment of laminitis?
Analgesia - NSAIDs, opiates in hosp
Foot support - Increase bedding, apply bandages, lilypads
ACP - vasoconstriction
Box rest - aided by ACP
High fibre, low concentrate diets
Treat underlying endocrine disorders
