The Rotten Truth Behind Rain Rot
By Jeffrey Rolo
Caused by the Dermatophilus congolensis bacterium, equine rain rot is
one of the more common skin infections that can
afflict horses and is actually unique in a couple ways:
The fungal infection does not progress further than the skin or cause
abscesses like other infections (such as strangles).
The cure actually hurts more than the infection!
Rain rot (also called rain scald) is an anaerobic infection that
requires the absence of oxygen to live and spread. When a
horse catches rain rot he will develop a series of crusty scabs and/or
matted/raised tufts of hair that, when pulled off, will
most often exhibit pink skin laced with some pus. Rain rot is
contagious, generally transmitted by shared horse tack (such
as blankets), mutual rubbing posts such as a fence, etc. Although
contagious, there are some factors that place the odds
against rain rot:
The Dermatophilus congolensis bacterium cannot survive when exposed to
air, so the horse's coat needs to remain wet for
a long period of time. This usually happens when moisture is captured
under a thick coat of winter hair.
There must be a way for the bacteria to get under the horse's skin, such
as an abrasion or a bug bite. If the bacteria
cannot reach the epidermis your horse is safe.
Given the way this infection works, the most obvious form of prevention
is keeping your horse dry during periods of intense
rainfall. Climates that are dry such as Arizona don't see much
occurrences of rain rot, while very humid areas like Florida
will be a far easier breeding ground for these bacteria. In addition
groom your horse often, particularly during the early
spring months. Not only will removing the winter coat make your partner
more elegant, it will make it far more difficult for
rain rot to take root.
What should you do if your horse does develop an unsightly case of rain
rot? First, don't let it stress you out – studies have
indicated a horse feels no pain, itching or discomfort from the
infection itself. It is also superficial and relatively harmless.
Ugly, yes – but harmless. That being said, rain rot should be addressed
as soon as possible to prevent the appearance of
secondary bacterial infections that also enjoy the presence of moisture.
Treatment consists of bathing your horse and lathering him in
antimicrobal shampoo. As you do this try to pick off the scabs,
but beware – this can cause discomfort and pain to the horse (remember
when I said the cure hurts more than the
infection?), so take it slow. The task might seem distasteful, but it's
necessary because otherwise the infection can continue
to thrive underneath the scabs. By removing the scabs you are exposing
the skin to air (and by default oxygen), which will
cause the infection to dry up and heal. The baths should take place for
approximately seven days.
Also important is to make sure the horse remains in a dry and ventilated
area during the treatment. Adequate protection
against bug bites should also be provided.
Finally, there are other bacterial infections, skin allergies and
parasites that can create symptoms that appear similar to horse
rain rot, so if you're uncertain of your horse's affliction you should
get assistance from your veterinarian.
The above article originally appeared on AlphaHorse, a website dedicated to
horses and the owners who love them. You will find many other informational articles dealing with horse training, horse care and more on their site.
Opinions expressed in articles on this website are those of the author(s)
of each story or article and not necessarily those of Shadow
Ridge. Shadow Ridge does not necessarily agree with, support, or
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