All Pets Veterinary Clinic


Gastrointestinal (GI) parasites, or parasites of the stomach, small intestine, large
intestine, and colon, are common in all of the domestic species. Without treatment,
these GI parasites can cause weight loss, anemia, failure to thrive, intestinal
compaction or blockage, diarrhea, or general unthiftiness. In addition, some of these
intestinal parasites can be transmitted to humans through the ingestion of parasite eggs.
Humans that have become infected with these parasites can have signs ranging from
vomiting, diarrhea, abdominal pain/cramping, blindness, and organ damage, among others.
Thus, GI parasites are of concern for more than just the household pet.

Fortunately, there are many veterinary products currently available to control
gastrointestinal parasites. The remaining portion of this article will look at the
common types of GI parasites that burden dogs and cats, the current recommendations
for deworming, and some of the products available for deworming

Common Intestinal Parasites

Roundworms and Hookworms are most commonly found in puppies and kittens. These
parasites can be passed directly from the mother before they are born or afterwords
in the milk. Additionally, animals of any age can become infected with roundworms or
hookworms through fecal-oral transmission. The eggs are very common in the environment
and animals can become infected by eating something contaminated with feces containing
the eggs.

Whipworms are more often found in adult animals but can be found in puppies
as well. Dogs are more commonly affected. Fecal-oral transmission is also how
animals become infected with whipworms.

Tapeworms are most commonly found in cats. Animals most often become infected
with tapeworms by ingesting fleas that are carrying the immature stages of the tapeworm
or by eating rodents, rabbits, etc. Thus, animals with flea infestations and animals
that are good hunters are more at risk for tapeworms.

Coccidia is a single celled parasite (i.e. not a worm) that commonly infects
dogs and cats. It is spread by fecal-oral transmission. Coccidia is very hardy and
can be hard to eliminate in the environment, thus animals kept in a coccidia
contaminated area can get coccidia multiple times.

Giardia is another single celled parasite that commonly infects dogs and cats.
It is also spread by fecal-oral contamination. Stagnant water (ponds, etc.) can also
serve as a reservoir for Giardia.


Roundworms, hookworms, whipworms, and coccidia are most easily identified with a simple
diagnostic test called a fecal floatation. A small amount of stool is mixed with
a solution that allows the eggs to float. The eggs can then be directly visualized
with a microscope. Tapeworm eggs tend to be very heavy and do not readily float.
They are most commonly diagnosed by finding tapeworm segements in the stool or on
the hair around the rectum. Giardia is very difficult to diagnose as well. A special
type of fecal solution often must be utilized to diagnose Giardia.

Deworming Recommendations

Many dewormers are available for treatment of these parasites. Unfortunately, none
of the over the counter or prescription dewormers will kill all of these parasites.
Thus, dewormers must be chosen according to the type of parasite that is present.

The following recommendations were recently introduced by the Compainion Animal
Parasite Council (CAPC) and detail control methods for internal (GI) parasites
for dogs and cats in the United States:

1. Administer year round broad-spectrum heartworm medications.

2. Deworm puppies and kittens at age 2, 4, 6, and 8 weeks of age and then monthly
until 6 months of age.

3. Deworm nursing dogs and cats at the same time as their offspring.

4. Conduct fecal examinations 2 to 4 times per year for adult animals, depending on
health status and lifestyle factors.

Deworming Products:

There are many products available for deworming purposes. Some of the most common

-Nemex: Kills roundworms and hookworms only.
-Drontal Plus: Kills roundworms, hookworms, whipworms, and tapeworms.
-Droncit: Kills tapeworms only.
-Panacur: Kills roundworms, hookworms, whipworms, and some species of tapeworms.
-Heartgard: Kills heartworms, roundworms, and hookworms.
-Interceptor: Kills heartworms, roundworms, hookworms, and whipworms.
-Sentinel: Kills heartworms, roundworms, hookworms, whipworms, and flea eggs.
-Revolution canine: Kills heartworms, fleas, ticks, ear mites, and mange in dogs.
-Revolution feline: Kills heartworms, fleas, ear mites, roundworms, and hookworms.
-Proheart: Kills heartworms and hookworms.

The decision of which product to use and how often depends on the health status of
the pet as well as several other factors. For a specific recommendation, please
consult with your regular veterinarian.

The information provided is for educational purposes only and is not
intended to take the place of your regular veterinarian. Please do not hesitate
to contact your regular veterinarian if you have questions regarding your pet.

Karen Blakeley, DVM, MPH
20 March 2004