Whipworm infection is transmitted by ingesting eggs that live in the soil. Once inside the host, the eggs hatch into larvae that travel to the large intestine and embed their long, whiplike tail into the intestinal wall. The larvae mature, mate, and lay eggs, which pass through the feces and into the soil.

Whipworm infection does not always cause symptoms. When symptoms do occur, they may include the following:

  • Anemia
  • Dehydration
  • Diarrhea, especially recurrent bouts of diarrhea with stool that has blood or mucus
  • Diminished strength and vitality
  • Weight loss

Whipworm is usually diagnosed by examining the feces for eggs. Infection can be difficult to diagnose and may require several fecal exams.

Several oral medications are available for the treatment of whipworm and monthly preventative medications also are available. Pet owners should discuss the options with their veterinarian.


Tapeworms are long, segmented worms that can live in a pet's small intestine. There are several species of tapeworms. For example, Dipylidium caninum develop as larvae in fleas (the disease carrier) and are transmitted when the cat or dog ingests the fleas while grooming. Taenia tapeworms are transmitted when a dog or cat eats infective eggs, which live in the soil or larvae, which live in small rodents. Taenia infection is more common among hunting dogs and cats.

Tapeworm infection generally causes very little harm to the host animal. Depending on the species, severe infection may cause the following symptoms:

  • Abdominal discomfort
  • Nervousness
  • Severe itching around the anus
  • Vomiting
  • Weight loss

Diagnosis is made by observing tapeworm segments, which look like rice, in the stool, near the anus, or on the pet's fur.

Treatment usually involves a single dose of praziquantel (e.g., Droncit, Drontal Plus, Rintal, Vercom). Preventative measures include flea control and, if possible, keeping your pet from hunting rodents.


Heartworm disease primarily affects dogs, but also affects cats. Heartworm (Dirofilaria immitsi) infection can significantly damage the heart, lungs, and other organs, and can be fatal if left untreated. Heartworm infection is transmitted through mosquito bites: a mosquito bites an infected dog and ingests heartworm larvae (microfilaria), which are passed to the next dog it bites. Microfilaria penetrates the dog's skin and travel through the body to the heart. It usually takes a few months for the infection to reach the heart; once there, the worms can grow to 14 inches.

Common symptoms of heartworm infection in dogs include:

  • Coughing
  • Diminished strength and vitality
  • Lethargy

Severe infestation can cause sudden death. Heartworms can

  • obstruct the heart chambers and blood vessels,
  • lead to the development of pulmonary hypertension (high blood pressure), and
  • cause heart failure.

Diagnosis is made by testing a small blood sample for the presence of microfilaria (heartworm larvae) or heartworm antibodies (proteins that defend the body against infection).

Treatment depends on the severity of the disease and usually involves administering 2 doses of injectable Immiticide.

Several preventative monthly medications are available (e.g., Sentinel, Interceptor, Heartgard). These medications are generally safe and can be administered year round, depending on the risk for the disease in certain geographical areas.

Cats and Heartworm

Cats are not natural hosts for heartworms and the risk for infection is lower than in dogs; however, cats can develop heartworm disease. According to the American Veterinary Medical Association, heartworms can cause severe reactions and death in cats. Heartworm infection in cats occurs more often in warm climates and in areas where dogs are at a increased risk.

Symptoms of heartworm in cats include the following:

  • Breathing difficulties
  • Coughing
  • Lethargy
  • Vomiting
  • Weight loss

These symptoms are easily confused with other disorders, especially bronchial asthma, making feline heartworm infection difficult to diagnose.

There is no approved product for treating heartworm infection in cats. Infected cats may suffer symptoms and die even after treatment.

Pet owners who are concerned about heartworm infection should discuss prevention with their veterinarian. A monthly preventative medicine is available, depending on the risk for the disease in cats in certain geographical areas.

Publication Review By: the Editorial Staff at HealthCommunities.com

Published: 01 Aug 2001

Last Modified: 26 Feb 2015