Page 379 - The Veterinary Care of the Horse

GENETIC PREDISPOSITION

Studies have revealed that the progeny of some stallions have a significantly higher incidence
VetBooks.ir of OCD, despite being reared under a wide range of environmental conditions.

GENDER

There is no evidence that either male or female foals are more prone to the development of
OCD lesions.

Sites affected

The most commonly affected sites are the:

a stifle

b hock

c fetlock

The shoulder, elbow, knee, neck and hip can also be affected. The lesions are usually
bilateral, even if the horse shows unilateral lameness.

Clinical signs

These include:
• mild to severe lameness

• joint swelling

• very young foals may lie down more than expected

• the disease may be asymptomatic.

It is thought that most OCD lesions develop by the time the foal is 5 months of age.

However, affected animals may not show any clinical signs until they are backed and begin
work.

Diagnosis

Diagnosis is usually made on the clinical signs (which can be very subtle) and confirmed by
radiography (Figure 8.14) Ultrasonography and scintigraphy can be helpful. Arthroscopy

allows direct inspection of the joint surfaces and detection of lesions not yet visible on
radiographs. Intra-articular analgesia may be used to confirm that a lesion seen on