Introduction
Most dogs, at some point in their lives, will need to be treated for whipworms. The medical name for whipworms in dogs is Trichuris vulpis. There is no particular gender, breed, or age predisposition for whipworm infection. As adults, these are 3-8 centimeter internal parasites that primarily live in the dog’s cecum, and possibly the ileum and colon, which are parts of the lower gastrointestinal tract.
Whipworms actually burrow into and embed themselves within the sensitive lining of the large intestinal wall. They cause a number of signs of large bowel inflammation, including severe bloody diarrhea (which may contain mucous), vomiting due to the large bowel inflammation, and weakness from dehydration, among other signs. Most dogs become infected when they eat the feces of other animals that contain whipworm eggs with the mature larval stage of the parasite.
When a dog ingests contaminated feces, the eggs settle in its digestive tract. The larvae go through several growth stages over a period of months and eventually become mature adults. Adult females begin laying enormous numbers of eggs (up to 2000 per day), which move through the host dog’s digestive tract and either settle there or are eliminated in the dog’s feces, and then the cycle begins again. Whipworm eggs are extremely resistant to environmental conditions and can remain infective for many years.
Treating Whipworms in Dogs
Once a dog has been conclusively diagnosed with whipworm infection, the current treatment of choice is oral fenbendazole, also called Panacur. Another common treatment is a combination of praziquantel, pyrantel and febantel, together commonly called Drontal (this treatment should not be used in pregnant animals). Any medical treatment of an infected dog with clinical signs should be accompanied by good supportive care, including fluid support to correct any dehydration or electrolyte abnormalities. These and other medications, and combinations of medications, can effectively kill the adult stage of whipworms in dogs with few if any adverse side effects. Your veterinarian is in the best position to help you decide which treatment is best for your dog.
Dogs that have been exposed to whipworms through eating contaminated feces are generally exposed multiple times. This means that there are probably different stages of whipworms in the dog’s intestinal tract at any given point in time. To eliminate maturing whipworms, the dog will need to have successive de-worming treatments. The first de-worming dose is given immediately upon diagnosis, then a second dose generally is given about 3 weeks later, and then a third dose is given in another few weeks. In severe cases, your veterinarian may alter this schedule.
If your dog has been diagnosed with whipworms, it is important to follow the de-worming schedule that your veterinarian gives you. Failure to follow the precise treatment protocols could result in whipworm reinfestation. It is also important to clean up all feces in your dog’s environment so that your dog - or other animals - will not become reinfected with these internal parasites. Environmental contamination is the source for reinfection and is quite difficult to eliminate. Monthly deworming is recommended for a time after the actual treatment for infection is complete, to reduce the chance of reinfection.