Horse Disease Focus - Rain Rot
What is rain rot?
Rain rot or rain scald is a common skin disease of horses. It is called 'rain' rot because it most commonly shows up in horses that have been turned out in the rain. (This is part of why people in damp climates have turnout rugs that are basically rain coats for horses).
Rain rot occurs on the horse's back, neck and haunches, and is a bacterial infection of the skin.
Rain rot looks worse than it is. The first symptom is a dulling of the coat, most often on the back, sides or haunches. Occasionally, it affects the legs, where it is sometimes called 'mud fever'.
The dull coat will come out easily if touched and the skin underneath is inflamed and oozing, often forming scabs. If the infection is not treated, the hair will fall out.
Rain rot is the most common equine skin condition there is. However, although it looks horrible, it appears to cause no direct discomfort for the horse...in fact, this is a literal case of the cure being worse than the disease.
Treatment starts with bathing the horse using an antimicrobial shampoo. Once the horse is bathed, the scabs should be removed. This process is not very comfortable for the horse...you may want to have somebody distract it and if you have a particularly sensitive horse, a mild sedative might be a good idea.
The horse should be bathed every day for about a week. That's usually enough to remove the infection. It also needs to be kept dry - do not turn a horse that already has rain rot out in the rain, or it will only get worse.
Disinfect any tack, rugs or grooming equipment that have been used on the infected horse and sanitize your hands. Rain rot can be transferred from horse to horse, so the infected animal should be quarantined until the infection is cleared up. (Note, however, that almost every horse has the bacteria on them - rain rot only occurs if there is a combination of moisture and broken skin - this is why it's so common).
Resting the horse is only necessary if the infected area would be under the saddle.
Grooming horses regularly is the best prevention for rain rot. Bringing your horse in during a heavy rainfall or using a turnout rug will also help a lot. If your horse does get soaking wet and you're there, dry it off as quickly as you can.
If you don't have an indoor and have to ride in the rain a lot, consider investing in a quarter sheet. This is either secured under the saddle like a saddle blanket, or over the saddle (some variations fasten around your waist). It's basically a slicker for your horse, although note that it can increase overheating - quarter sheets should not be used in warm climates.
Avoid sharing tack and grooming equipment between horses as much as possible.