What diagnostic method is preferred for detecting eggs of the equine pinworm in a horse?

The Scotch tape test is the preferred diagnostic method for detecting eggs of the equine pinworm (Oxyuris equi) in a horse. This technique involves applying adhesive tape to the perianal region of the horse, where the female pinworm lays her eggs. The eggs can then adhere to the tape, making it easy to collect and examine them under a microscope.

This method is particularly effective because the eggs of the equine pinworm are not typically found in feces; instead, they are laid on the skin around the horse's anus. By using the Scotch tape technique, veterinarians can obtain a sample directly from the source where the eggs are deposited, increasing the likelihood of detecting them.

While fecal flotation tests are useful for identifying other types of parasites that shed eggs in manure, this method is not suitable for pinworms since their eggs do not commonly appear in fecal matter. Blood smears are mainly used for detecting certain blood-borne parasites and would not be applicable in the case of pinworms. Direct observation under a microscope without prior collection methods like the Scotch tape test would also be ineffective, as it would not yield the pinworm eggs easily. Thus, the Scotch tape test is the most effective and reliable method for diagnosing