Conditions or ailments that are the cause of a problem that you see - your observation.

Your vet may diagnose

Pinworm Infestation


Pinworms (Oxyuris equi) are an intestinal parasite that live in the horse's lower intestines. They deposit their eggs around the anus, causing intense itchiness.

The classic sign of this parasite is frequent scratching of the area around the anus and tail head (against a fence, door or other structure). Tail hairs tend to be broken off at the base due to intense scratching.

This diagnosis actually requires the so-called "scotch tape test", in which scotch tape is stuck to the anus and removed. The eggs adhere to the tape and can be examined and identified under a microscope.

my vet's role


Historically, treatment for pinworms has been effective in decreasing signs. There may be resistance in the pinworm population to our common dewormers, making treatment more difficult.

my role

further reading & resources

Author: Doug Thal DVM Dipl. ABVP