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Cannon Crud

What is the fungus horses get on the front of their cannon bones on their back legs and how can I get rid of it? – via


I believe what you’re referring to is technically called Cannon Dermatitis or Cannon Keratosis. It’s also affectionately known as “cannon crud” or even “stud crud.” However, it’s not caused by a fungus, and it’s not just seen in male horses. This crusty, greasy … “ick” on the front of some horse’s cannon bones is an inflammation of the skin (that’s where the word “dermatitis” comes from) that has as a component horny skin growth (that’s where the word “keratosis” comes from). It’s not infectious or contagious, and it can appear in either gender, all breeds, and just about any age of horse. Is there a genetic predisposition? Maybe, as some horses seem to get it while others living in the same environment, eating the same food, and doing the same work don’t seem to get it.

Just to be sure what you’re dealing with though, I highly recommend that you point it out to your veterinarian the next time he or she is at your barn. That’s because many skin conditions can look the same and you and your horse might get a little frustrated if you’re treating one thing (like rain rot or scratches) but it’s actually something else. Plus, if it’s a more serious dermatological issue, you’d want to start treating that appropriately right away rather than delay proper care.

Your veterinarian may suggest a regimen for cleaning your horse’s legs then applying a topical product to help them stay clean. The good news is that there are a lot of products and protocols that help keep this condition at bay; the bad news is that there are a lot of products and protocols that help keep this condition at bay. What that means is that it may take some trial and error before you stumble upon the best method to clear up the condition in your horse. Word of advice while you’re experimenting though: avoid being too aggressive by using products not designed for the skin or by physically aggravating the site by excessive scrubbing or picking as you might make things worse. Keep calm and clean on!



Lydia F. Gray, DVM, MA SmartPak Staff Veterinarian and Medical Director Dr. Lydia Gray has earned a Bachelor of Science in agriculture, a Doctor of Veterinary Medicine (DVM), and a Master of Arts focusing on interpersonal and organizational communication. After “retiring” from private practice, she put her experience and education to work as the American Association of Equine Practitioner’s first-ever Director of Owner Education. Dr. Gray continues to provide health and nutrition information to horse owners through her position at SmartPak, through publication in more than a dozen general and trade publications, and through presentations around the country. She is the very proud owner of a Trakehner named Newman that she actively competes with in dressage and combined driving. In addition to memberships in the USDF and USEF, Dr. Gray is also a member of the Illinois Dressage and Combined Training Association (IDCTA). She is a USDF “L” Program Graduate and is currently working on her Bronze Medal. Find Dr. Gray on Google+

Posted in Ask the Vet, Basic Health Care, Skin, Coat & Hooves

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5 comments on “Cannon Crud
  1. Phi says:

    My mare has this and I finally found something that works! Scrub with a soft curry and spray with diluted Listerine! I bought one of the huge bottles and it lasted me all year. I applied twice a day and after bathing. 🙂

  2. Belinda says:

    I tried this after a fried suggested it and it worked for me. I use original blue Dawn once or twice a week and a medium dish brush (one you actually put the soap in) in the summer on my gelding. Once I gone the crud under control I dropped to once a week for maintenance. It hasn’t come back yet since the end of bathing season so fingers crossed!

  3. Alfred says:

    A squirt of baby oil over it loosens it up in seconds, and it easily washes off.

  4. Marlene Polson-Lorczak says:

    I have had this “Crud” problem in the past and through trial and error found a great product that works. It is called EQUIDERMA SKIN LOTION.
    I recommend this to all my friends who have horses with cannon crud.
    The best news is SMARTPAK now carries Equiderma products. The product is a blue lotion and you should see results within a week and sometimes only 3 days! Good Luck

  5. Joannette Korngold says:

    There is a product called Equine APS that heals scratches and any non infected wound. It has over 30 million dollars of research to substantiate its findings. It may work on this condition too!

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