Also known as rain scald, rain rot is a skin infection caused by Dermatophilus congolensis , bacteria that thrive in high-moisture conditions. When a horse’s thick winter coat gets and stays wet due to cold temperatures, the skin underneath becomes a prime breeding ground for the bacteria. Rain rot can also occur in horses with lighter coats when blankets get soaked.
Keeping your horse dry is the best prevention, but that’s not always realistic since most horses need to be turned out and exercised regularly, even in cold, wet conditions. The next best thing is to dry your horses with towels and -- if you think your horse will tolerate it -- a blow dryer, immediately after bringing them in from the rain or snow. Another important aspect of prevention is to groom your horse frequently, at least twice a week, brushing away mud and dirt. When grooming, check for those tell-tale signs of rain rot: sensitive skin, scabs and bumps.
Brian A. Crook, DVM
Rain Rot on a horse
Rain rot on a horse
Spot the Rot
The back and rump are the most likely areas where you will see evidence of rain rot. Often, your horse’s coat will begin to stand up in a peculiar pattern and as you rub your hand on the coat you will feel the heat radiating from the skin. Within a day, tiny scabs appear that feel like small bumps. If untreated, the tiny scabs can quickly progress to crusty, thick scabs and lesions.
At an advanced stage, large crusts can develop that are easily noticeable and can cause significant itchiness, pain, and discomfort. Your horse may resist even a light touch of your hand.
Treating Rain Rot
Air is a natural enemy of the bacteria that cause rain rot. That’s why it’s important to remove the scabs to allow air to reach the bacteria. In the early stage of rain rot, this can be done by lightly grooming the horse with a rubber curry brush. It is advisable to wear latex or rubber gloves when dealing with rain rot. For the best treatment, clip the area first and gently wash with a mild soap. Since the skin is often sensitive, it is best to soften the scabs by applying a natural oil blend that aids in healing. Look for products containing three important essentials oils: Eucalyptus, Lavender, and Tea Tree oils.
As the scabs soften, you can gently scrub affected areas and remove as much crusting as possible. If a scab seems extremely sensitive or begins to bleed, apply additional topicals and allow the scabs to soften. Repeat the process daily until all crusts are removed and skin has healed over. Hair regrowth is usually rapid once the infection has been eliminated.
If your horse has a severe case of rain rot, or you don’t begin to see improvement after a week of home treatment, call your veterinarian for guidance.
Prevent Recurrence
To prevent reinfection, protect your horse from rain and snow. If he gets wet, dry his coat as quickly as possible using an absorbent towel and a blow dryer.
Avoid contact with other animals infected by the bacteria. Do not use the same grooming tools you use on infected horses with those not infected.
While any horse can develop rain rot, horses with weak immune systems are more likely to contract it, and may experience a more severe case. Take extra precautions for senior horses and those with compromised immune systems to keep them in dry environments.
It is important to be aware of rain rot and how to prevent and treat this condition so your horse will remain healthy and happy during those cold winter months.
Dr. Brian A. Crook received his
Doctor of Veterinary Medicine degree from Colorado State University and practiced for several years in Denver. He is currently president of Vital Animal Health, which partners with Manna Pro Products to produce an all-natural line of CalmCoat® equine products for skin and eye health, including Natural Topical, Natural Fly Repellent, and Calm Eyes, as well as a line of premium shampoos, conditioners and detangler products by CalmCoat®. Learn more about CalmCoat® products at www.calmcoat.com .
See also Shari’s Healthy Horse Hints “ Tips to Prevent and Treat Skin Infections ,” including:
- Factors affecting skin
- Healthy skin no-nos
- Skin-friendly supports
- Skin foes
- Clipping options