Conditions or ailments that are the cause of a problem that you see - your observation.

Your vet may diagnose

Cannon Dermatitis or Keratosis

Synonyms: Stud Crud, Urine Scald or Burn


Cannon keratosis is a skin disease that affects the front of the rear cannon (lower leg) regions. It results in scurfy, scaly skin and hair loss over the front of the cannon region of both hind limbs. It's exact cause is not known but it is likely caused by a combination of factors, including genetic predisposition. There is actually no breed, age or sex predisposition, so it is not as simple as urine splashing up onto the fronts of the cannons in male horses.

Cannon keratosis occurs more frequently in the "thin-skinned" breeds (Thoroughbreds and TB crosses). In most cases, the condition is not irritating to the horse and just appears as scurfy to scabby area on the front of the lower limbs. Rarely, the condition worsens and the affected area becomes swollen, painful or oozing. This is likely caused by a bacterial infection of the damaged, compromised skin.


Diagnosis is by appearance. Biopsy is not considered very helpful.


There is no real treatment for Cannon Keratosis. A rubber curry can help remove extra hair and debris. Periodic cleansing and removal of crusts and debris with keratolytic (anti-dandruff) shampoos can be helpful in managing the condition and improving its appearance. Anti-dandruff creams, and topical steroid creams may also help.

As long as the affected area is quiet and not causing the horse discomfort, it may not be treated at all. However, if the area is swollen, inflamed or painful, there usually is an infection and treatment is indicated.

my vet's role



Other conditions or ailments that might also need to be ruled out by a vet.

Very Common
Less Common
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The prognosis is poor for completely resolving the condition.

However, generally this condition does not seem to cause horses much discomfort, so many choose to ignore it, or simply manage it to keep it quiet.

my role

Questions To Ask Your Vet:
  • Is the affected area infected?
  • Is treatment of this condition worthwhile?

There is no known method of prevention.

further reading & resources

Related References:

Higgins AJ, Snyder JR eds. The Equine Manual. 2nd Ed. Edinburgh: Elsevier Saunders 2006.

Author: Doug Thal DVM Dipl. ABVP