How to Clean Cannon Bone Crud on a Horse: A Veterinarian’s Step-by-Step Demonstration

Cannon bone keratosis—often called cannon crud—can appear as a dark gray or black, waxy, flaky buildup on a horse’s cannon bones. In this video, veterinarian Dr. Keelin Hurd demonstrates the routine she uses with Medica Treatment Wash on Ray, her own horse, for a very mild case.

What does cannon crud look like?

Keelin begins by showing the buildup on the front of one of Ray’s hind cannon bones and a smaller area on the back of the opposite leg. She describes it as a black or dark gray, waxy, flaky substance. Because Ray’s case is mild, this is best viewed as a practical washing demonstration rather than a dramatic before-and-after transformation.

How Keelin cleans a mild case of cannon crud

1. Wet the hair all the way to the skin

A horse’s coat naturally repels water, so wetting only the surface is not enough. Keelin works carefully until the water reaches the skin beneath the hair.

2. Shake the Treatment Wash and apply it to the affected area

After shaking the bottle well, Keelin uses roughly a quarter-sized amount for the area shown. The amount needed will vary with the size of the affected area and the horse’s coat.

3. Work the wash through the hair gently

Keelin rubs the wash through the hair so it reaches the skin and creates a thorough lather. She does not use a tool or her fingernails to scrape or aggressively scrub the buildup.

4. Allow contact time, then rinse thoroughly

After allowing the wash to sit during this demonstration, Keelin rinses carefully until no suds remain. She checks the runoff and uses her hand to gently squeegee water from the leg. If hidden suds appear, she continues rinsing.

Always follow the current directions for Medica Treatment Wash and your veterinarian’s recommendations for your horse.

5. Remove excess water and towel dry completely

Keelin removes the excess water by hand and then uses a clean, dry towel. She dries above and around the affected area as well as the leg itself, helping prevent water from running back down onto the freshly cleaned skin. Her practical rule is to keep drying until the towel is wetter than the leg.

6. Inspect the leg and the towel

Because Ray’s case is very mild, his leg looks clean immediately after washing. The white towel also makes it easy to see the small amount of dark, waxy debris removed during the routine.

What about recurring or more substantial cannon crud?

Ray is prone to this type of buildup, so Keelin explains in the video how she incorporates Treatment Wash into his ongoing lower-leg care. If your horse has a more substantial or recurring case, use the product according to its current directions and talk with your veterinarian about the right schedule and whether another skin condition may be involved.

Avoid painful picking or aggressive scraping. Contact your veterinarian if the skin is painful, swollen, bleeding, draining, rapidly worsening, associated with lameness, or not improving.

The bottom line

A careful routine matters: wet through the coat, distribute the wash to the skin without aggressive scrubbing, rinse until no suds remain, and dry every area that was wetted.

Ready to add it to your barn routine? Shop Medica Treatment Wash.

This article is educational and does not diagnose or prescribe treatment for an individual horse. Consult your veterinarian about your horse’s specific needs.