Re: Let's Discuss Worming

[ChacoL@aol.com]

My worming program:

Frequency - When horse is shod (less taxing on memory!)
Products - Class I (pyrantel), Class II (benzimidazole), Class III
(ivermectin)
Rotation - Annual

I use an annual rotation because parasites are least likely to develop
resistance.  The most likely program for developing resistance is rapid
alternation--using a different product each time you worm.  This leads to
multiple resistance.  The exception to this program is to use ivermectin in
the fall if bots are a concern, and to give a double dose of pyrantel for
tapeworms once a year.

A researcher at Merck once told me that small strongyles are the only worm in
horses that has developed a resistance, and that is to benzimidazoles.  The
above recommendation comes from the same source.

Another recommendation:  If you want to run a fecal sample, be sure the lab
uses the "swinging-head centrifuge" technique rather than the "float
technique" because the latter doesn't show eggs well enough.

After a serious bout with ehrlichiosis, a tick-borne disease, my vet
recommended an injection of Ivomec (ivermectin) as Jennifer Layman does.
Although the paste version doesn't control external parasites, the injection
does a neat job.  As discussed earlier on Ridecamp, the injectible ivermectin
is no longer labeled for use on horses, but my vet explains this was because
of some negative reactions to the injection itself and not from the
ivermectin.  I would do this again should ticks or mites become a problem.

Linda
San Francisco