Intestinal parasites are far more common than you might believe. With the change of the seasons, your pet probably spends more and more time outside increasing his exposure to these parasites. Not only can intestinal parasites threaten your pet's health, but some of these bugs can harm you and your children. Commonly seen intestinal parasites include worms (such as roundworms, whipworms, hookworms, and tapeworms) and protozoa (such as coccidia toxopasma and giardia).

Most intestinal parasites are spread by fecal-oral transmission. Your pet may ingest dirt, another animal's droppings or contaminated water from puddles or ponds and become infested. Dogs and cats with intestinal parasites may exhibit the following clinical signs: diarrhea, vomiting, constipation, inappetance and weight loss. Often healthy, well-fed animals show no signs of disease.

Although tapeworm segments resembling grains of rice may be seen in your pet's stool with the naked eye, most internal parasites may only be detected via microscopic examination of the animal's feces. Once intestinal parasites have been diagnosed, your veterinarian will recommend the appropriate treatment.

After your pet has been dewormed, the following steps may be taken to prevent subsequent infestation. Keep your pet away from dirty water and other animals' stool, and ask your veterinarian about medications that may be given monthly to prevent fleas and intestinal parasites (as well as ticks and heartworm). Fecal examinations should be performed by your veterinarian annually to ensure that your pet is parasite-free.

The writers are Dr. Steven B. Holzman, Dr. William R. Haagenson, Dr. Angela N. Martin and Dr. Loretta Dougherty. They are associated with the Nassau-Suffolk Veterinary Hospital of Farmingdale.