Re: RE scratches

[CMKSAGEHIL <CMKSAGEHIL@aol.com>]

In a message dated 98-04-05 22:57:16 EDT, you write:

<< I had a horse who did this terribly.  The only thing that helped was
 taking him off clover.  That fixed it immediately.   >>

Scratches is a complicated, multifaceted problem.  In cases where
photosensitivity is a factor, there is almost always a chemical cause (such as
clover, or in some cases, even rapidly growing green grass) that triggers the
photosensitivity.  Although wrapping may block the light rays, the best course
is to remove the chemical cause.  Wrapping, in my experience, makes the actual
disease worse in many cases, so getting the horse out of the sunlight during
the day by stalling him is preferable.

Most cases, however, are a combination of fungal and bacterial infection.
There is often an allergic component which keeps the area irritated and more
open to infection.  With simple cases, I start with a mixture of 1/3 DMSO, 1/3
nitrofurazone ointment, and 1/3 one of the "bendizole" paste wormers.  This
works well in many cases, but if there is a lot of swelling, I add oral sulfa-
trimethoprim and sometimes injectable dexamethasone.  The sulfa-trimethoprim
addresses the bacterial infection internally, and the dexamethasone helps to
alleviate any allergic reaction that may be prolonging the disease.

With horses that are prone to scratches, liberal use of Desitin or other forms
of zinc oxide before the disease gets a foothold will often keep the problem
from developing fully.  The beauty of zinc oxide is that it is not absorbed
and hence does not "test" so it can be used in competition.

Heidi Smith, DVM--Sagehill Arabians (Oregon)