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Rain rot shows up fast in a Florida summer. A horse that stands out in daily afternoon storms and never fully dries off can go from a smooth coat to crusty bumps along the back in a short time. The good news is that most mild cases clear with steady care. Here is how we handle it, what we keep in the wash rack and when it is time to call the vet.
For the rest of our barn gear, see the Amazon horse supplies we keep in our Ocala barn.
What is rain rot in horses?
Rain rot, also called rain scald or dermatophilosis, is a skin infection caused by the bacterium Dermatophilus congolensis. It thrives on skin that stays wet, and it often starts along the topline, rump and neck where rain runs off the horse. Similar crusting on the lower legs is often called scratches or mud fever, which can have several causes; ask your vet.
Extension specialists at Penn State note that the bacterium mostly sits dormant on the skin and causes trouble when skin stays wet or is broken by rain, humidity or insect bites.
Common signs:
- Raised, crusty scabs that lift off with tufts of hair, sometimes called a paintbrush look.
- Small bald patches with pink or moist skin under the scabs.
- Tenderness when you groom the area.
- Spots that cluster where water runs down the body.
How do you treat rain rot?
Most mild cases of rain rot clear up when you keep the horse dry, gently lift off loose scabs and wash with a medicated shampoo, then dry the coat well. Use separate tools so it does not spread. Severe cases may need a prescription antibiotic from your vet, so call if it is spreading or the horse seems sore.
Step 1: Get the horse dry
Moisture feeds the infection. Bring the horse in during storms if you can, or give turnout access to a run-in shed. Treatment works poorly on a horse that is soaked every afternoon.
Step 2: Loosen and remove scabs gently
Soften scabs with a medicated shampoo and warm water, then lift off the ones that come away easily. Do not pick or scrape scabs that are stuck; that hurts and can open the skin.
Step 3: Wash with a medicated shampoo
Lather, let the shampoo sit on the skin for the contact time on the label, then rinse well. Leftover soap can irritate skin.
Step 4: Dry thoroughly
Use a sweat scraper and clean towels, then let the horse dry in shade with good air flow before turnout or a sheet goes back on.
Step 5: Keep tools clean and separate
Use separate brushes and towels for the affected horse and wash them between uses so you are not moving bacteria around the barn.
Rain rot shampoo and spray we link to
Vetericyn FoamCare Medicated Horse Shampoo
Vetericyn FoamCare Medicated Horse Shampoo (32 oz) (paid link) is a medicated horse shampoo in a 32 oz bottle. It is a reasonable first choice for the wash-rack step above because you can lather, let it sit and rinse. Read the label for how often to use it and how long to leave it on. See Vetericyn FoamCare on Amazon (paid link).
If you want a leave-on spray or a stronger medicated product, ask your vet which one fits your horse. Some cases need a prescription product, and the vet can confirm it is rain rot and not a fungal problem or an allergy.
Why is rain rot so common in Ocala?
Rain rot needs wet skin, and a Central Florida summer brings heat, high humidity and frequent afternoon storms. Horses on pasture can stay damp for long stretches, and a coat that never dries gives the bacteria a steady place to grow. Insect bites can also break the skin and give the infection a way in.
How do you prevent rain rot?
You prevent rain rot mostly by keeping skin dry and clean. Give horses shelter they will use in storms, check under sheets after rain, groom daily so you catch small scabs early, keep each horse’s brushes separate and control the biting flies that break the skin. A few habits cover most of it:
- Give horses shelter they will actually use during storms.
- Check the coat under fly sheets after rain. A wet sheet can hold water against the skin. We cover sheets and masks in our guide to the best fly spray for horses in Florida, including our pick, the HILASON UV mesh horse fly sheet (78 in) (paid link).
- Keep each horse’s brushes and towels in its own tote. A Little Giant DuraTote grooming tote (paid link) makes that easy.
- Groom daily so you catch small scabs early.
- Control flies, since bites can open the skin.
Wet season is hard on hooves too. Our thrush treatment and hoof care guide covers the same soggy months from the ground up.
When should you call a vet?
Call your vet when rain rot is spreading, covers a large area or the horse seems unwell. A vet can confirm it is rain rot and not a fungal infection or allergy, and can prescribe treatment for severe cases. Young horses, older horses and horses with other health problems deserve an early call. Watch for these signs:
- The scabs spread quickly or cover a large area.
- The horse is lethargic, off feed or has a fever.
- The lower legs are swollen, hot or painful.
- There is no clear improvement after a couple of weeks of steady care.
- Your horse is young, old or has other health problems.
FAQ
Is rain rot contagious?
It can spread between horses through shared brushes, towels, blankets and tack, and through contact. Keep tools separate and wash them.
Should I pick the scabs?
Only remove the ones that lift off easily after softening them with shampoo. Forcing stuck scabs off is painful and can damage the skin.
Can horses be ridden with rain rot?
Avoid putting a saddle, pad or girth over active scabs. If the spots are elsewhere and the horse is comfortable, ask your vet.
How long does it take to heal?
Texas A&M veterinarians say most mild to moderate cases resolve in two to three weeks with proper care (Texas A&M College of Veterinary Medicine). Hair may take longer to grow back. If it is not getting better, call your vet.
See our full list of Ocala barn essentials for the rest of our wet-season kit. This is general barn care information, not veterinary advice. Follow the product label and ask your vet about anything that worries you.