Chagas Disease in Dogs

Chagas disease or American trypanosomiasis is a tropical parasitic disease that is beginning to be reported in Texas, where it has spread from Mexico. Chagas disease is quite rare in both dogs and people in the U.S., but is of increasing concern because of emigration from endemic areas of Central and South America. The disease can occur in many species but we’re seeing it mostly in humans and dogs. 


The primary method of transmission (vector) is by a blood sucking insect called the “kissing bug.”  Kissing bugs are so named because they bite victims near the mouth. There are a number of types of kissing bugs and various species are found throughout the United States. Fortunately, although all kissing bugs are able to transmit Chagas disease, only a few have been identified as being likelyTwo dogs sitting on haystack to do so.

How is Chagas disease transmitted to dogs and humans?
According to the CDC, Kissing bugs transmit the infection in their feces. The organism enters through a bite wound when the insect feeds or through the mucus membranes. It may also be transmitted from a mother to her offspring either by way of the umbilical cord (before birth) or milk (after birth).

What are the symptoms of Chagas disease?
Incubation requires five to 42 days. There are three phasesof the disease in animals as described by Texas A&M Veterinary Medical Diagnostic Laboratory:

  • The acute phase, occurs primarily in younger animals and involves the heart (myocarditis and cardiac arrhythmias) and may result in collapse and sudden death. Other sings in the acute phase may include fever, anorexia, lethargy, swollen lymph nodes, an enlarged liver or an enlarged spleen.
  • The latent phase, may have no symptoms and can last for years following infection.
  • During the chronic phase, the disease primarily affects the heart and may result in heart failure. Sudden death is possible.

How is Chagas disease diagnosed?
Early in the disease, the organism can be seen under a microscope in the blood stream. Specific blood tests are needed to identify it later in the infection.

How is Chagas disease treated?
There is no treatment for Chagas, that’s why prevention is so important.

Is Chagas disease transmissible to humans?
Though still relatively uncommon in the U.S., Chagas disease will undoubtedly become more frequently diagnosed. Although direct transmission from dogs to humans has not been reported, infection in dogs indicates the local presence of infected vectors, which may present an increased risk of vector-borne transmission to humans.

Prevention of Chagas
There is currently no vaccine available against Chagas disease for dogs. According to the Companion Animal Parasite Council, the best way to prevent infection is to avoid the vectors that cause it:

  • Insecticides may be considered to reduce local populations of the kissing bug.
  • All blood donations should be carefully evaluated for infection.
  • Breeding females should be checked for antibodies.

If you have any questions or concerns, you should always visit or call your veterinarian -- they are your best resource to ensure the health and well-being of your pets.

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Reviewed on: 
Tuesday, May 27, 2014

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