Controlling Rain Rot
Source: Mark Russell, Assistant Professor - Equine U of A
As Arkansas approaches a more wet time of year (at least we hope), one of the major considerations for horses housed outside is the potential of developing rain rot, aka dermatophilosis. It is also known as rain scald or mud fever. It doesn’t have to just be a fall or winter condition but can also been seen (although with less frequency) during the spring. Dr. Anthony Yu, DVM, MS, Dipl. ACVD of Ontario Veterinary College, states:
The Dermatophilus organism needs moisture to proliferate, release, and spread the infective forms of the bacteria, called zoospores. Horses might become infected from direct contact with contaminated fomites (inanimate objects or substances capable of carrying infectious organisms; for example, the bacterium can survive dormant in bits of fallen-off scab for months) or an asymptomatic carrier, or indirectly through transmission by insects.
In simpler terms, the disease can be spread through insects and can also be spread from horse to horse. There have also been some cases where rain rot was found in dirt the horse had rolled in.
Rain rot can mostly be seen along the back of a horse – from neck to croup. It can also be seen on the legs. It appears that the condition itself doesn’t cause pain. However, if contact is made with the affected skin or the scabs are picked off, there may be some discomfort and/or pain for the horse. There are various medications available to treat the condition. Most feed stores or co-ops will have the necessary treatment. Listerine® has also been said to have a positive effect on rain rot. It can be treated like a fungus, thus many disinfectants will do the job. Ensure the area is dry once treatment is applied as well. There are also times when it goes away on its own. If skin becomes infected and doesn’t appear to be healing properly, call your veterinarian to determine the best plan of action.
What does it look like?
Scab-type lesions
Loss of hair
Raised tufts of serum-matted hair
Red or irritated areas under hair
Tips to keep it from spreading
Don’t share tack, equipment or blankets between horses you suspect may have rain rot.
Keep infected horses isolated.
Minimize exposure to bacteria and bugs.
After treating the infected horse, wash hands thoroughly.
Have a covered area for your horses.
Keep coat clean – especially for horses turned out more than others.