Page 236 - The Veterinary Care of the Horse

Prognosis

The prognosis is good if the condition is treated early and the underlying cause can be
VetBooks.ir removed. In horses with contracted heels and deep, narrow frog clefts it can be very difficult

to clear up. Long-term corrective trimming and shoeing by the farrier may be required to
improve the hoof conformation.

Prevention

The condition is easily prevented in most horses by regular hoof care and good stable
hygiene. This is especially important in horses confined to their boxes for long periods.

CANKER

Canker is a disease that affects the epidermal (outer) tissues of the foot. The frog, bars, heels
and sole of the foot are most commonly affected. The tissues are infected with bacteria

including Fusobacterium necrophorum and Bacteroides spp. Horses living in damp
conditions or kept on dirty, wet beds appear to be particularly at risk. It is most commonly

seen in heavy horses but can occur in any breed. It has been suggested that the disease may
be an immune response to bovine papilloma virus which causes warts in cattle and is also

associated with sarcoids in horses. The condition is less common than it used to be.

Clinical signs

• The horn of the frog has an abnormally ragged appearance with loose, detached fronds of

horn (Figure 6.30).
• The infection can spread from the frog to the bars, heels and sole. Occasionally the wall

is involved.

• Tissue that resembles granulation tissue and bleeds easily may grow out from the affected
areas.

• The foot has a very unpleasant odour and a creamy, white discharge.

• There is a variable degree of lameness depending on the extent and depth of the
infection. When the deeper, sensitive structures of the foot are involved, the resultant

inflammation causes pain and lameness.