Things You Need to Know About Canker in Your Horse

Hoof maintenance for your horse is one of the most important aspects of their overall health and wellness. Making sure your horse is comfortable on its feet is important for them to continue living a happy, healthy, and active lifestyle. Hoof maintenance includes trimming the hoof, changing shoes, and keeping a dry and clean environment for your horse to stand in. Bruising and infection in the hoof is possible and not uncommon. One of the most common infections is canker. Canker is painful for your horse and must be treated properly for the infection to clear completely. Keep reading on to learn more about the cause of canker, how to diagnose it, and most importantly how to treat a canker in your horse.

Things You Need to Know about Canker in Your Horse

The Cause of Canker

The cause of canker in horses is due to bacteria causing an overgrowth of the horn, or abnormal keratin production. Once this overgrowth begins, a lack of oxygen to the frog can cause cankers to start. One theory that suggests canker developed in low hygiene conditions has been disproved. The top reason we see canker develop is due to inadequate hoof trimming schedules. Instead of a 4-6 week cycle, canker is commonly found in horses on an 8+ week cycle. Stretching out the trimming cycle causes an overgrowth of hoof walls, creating a large space for dirt, manure, and urine to pack in. 

Symptoms and Diagnosis of Canker

Early symptoms of canker include bad odor, exudate that is white/yellow in color, tentacles of abnormal tissue (similar to an octopus), “blooms” of proud flesh and abnormal tissue, tissue bleeding easily, and mild advancing to profound lameness. 

Canker can oftentimes be misdiagnosed as thrush when diagnosed in its early stages, and a veterinarian should always conduct a thorough examination of the horse’s leg and hoof before a diagnosis is made. To make the official diagnosis, your veterinarian will take a tissue biopsy. 

Things You Need to Know about Canker in Your Horse

Treatment for Canker

Veterinarian Dr. Frank Reilly of Equine Medical and Surgical Associates has developed Equine Canker Powder paired with a 4-step program to clear the canker infection and get your horse’s hooves back in peak health.  This program is guaranteed to show improvement in 14-21 days, reduce lameness, stop foul smells, and is easy to follow. Equine Canker Powder is a proprietary blend of desiccants, antibacterials, antifungals, vitamins, herbs, and anti-inflammatory agents including MSM, Matricaria, Magnesia desiccant, Metronidazole, Ketoconazole, SMZ/TP, and Vitamin E. The 1-gallon bucket is enough to treat 2 feet for 4 weeks to clear horse canker.

Overview of EMSA 4-Step Equine Canker Powder Program:  

  1. Use Oral Doxycycline given 2 times a day for 30 days. Oral doxycycline is mandatory in helping clear canker. Oral doxycycline inside the body and medicated canker powder on top of the canker is a powerful combination. Doxy must be ordered by your vet and in the barn ready to go prior to medicated canker powder being sent. Once doxy is in place and Dr. Reilly consults with the barn vet, the protocol for medicated canker powder can begin.
  2. Use medicated canker powder for 28 days with surgical debridement on days 4 and 13.  A 1-gallon bucket treats 2 feet in a draft horse. 
  3. Give your horse a single dose of Ivermectin oral paste (dose by the bodyweight like regular deworming). This addresses possible nematode aspects that can be a part of canker. This is done on day 1 of medicated canker powder.
  4. Routine hoof trims are not to exceed 5 weeks between trims. 

Things You Need to Know about Canker in Your Horse

More in-depth information is provided here on our in-depth page for Equine Canker and here for our Canker Powder 4-Step Program. Please reach out to Dr. Frank Reilly at or call 610-436-5174 with questions or to start your horse on Equine Canker Powder. Free shipping is available on all orders over $120.