Anne M. Zajac, DVM, PhD, DACVM (parasitology)

Most parasitologic diagnoses are straightforward, but there are several situations where making diagnosis of parasitic infection or disease is more difficult and potentially confusing.

The challenging area of heartworm prevention and control has become even more challenging in the past few years as new information becomes available.

Giardia and Isospora spp coccidia are the protozoan parasites encountered most frequently in small animals.

Traditional livestock species are becoming more popular in suburban and semi-rural areas where small animal clients may own several acres of land and in municipalities that are becoming more lenient with restrictions on livestock and poultry.

In recent years, concern about the zoonotic potential of parasites encountered in small animal practice has risen substantially.

Ticks are increasing in importance in small animal practice because of their ability to cause irritation and tick paralysis and because they vector several diseases.

At a minimum, veterinary practices should be able to perform in-house diagnostic tests for heartworm infection and detection of parasites in fecal samples.

In addition to the common parasitic infections encountered frequently in practice, veterinarians need to be alert for the occasional parasite new to you because it typically is limited to other parts of the US or the world.

One of the most familiar genera of nematodes in small animals, Toxocara, has been the focus of several recent studies and the results of these studies alter some of our basic understanding of these parasites.