Your Guide to Chagas Disease in Dogs

What is Chagas disease in dogs?

Also known as kissing bug disease or American trypanosomiasis, Chagas disease is a serious disease affecting the blood, muscles and hearts of people and dogs. This parasitic condition is spread by triatomine insect vectors known as 'kissing bugs'. Although Chagas disease is seen primarily in Latin America it is becoming increasingly common across the Southern United States. 

How do dogs get Chagas disease?

Chagas disease is caused by a blood parasite called Trypanosoma cruzi. This parasite is spread in several ways:

• Ingestion of the feces left behind by infected kissing bugs after they feed.
• Infected feces rubbed into eyes.
• Ingestion of the infected bugs.
• Ingestion of animals infected by the parasite (hosts) such as rodents, raccoons or squirrels.

Once the parasite enters your pet's body it invades various cells, including those in the heart, liver, spleen, kidneys, skeletal muscle, lining the blood vessels and central nervous system, and begins to multiply. As the number of Trypanosoma cruzi increase the cells explode and release more parasites into the dog's bloodstream.

Any dog that lives in Southern states where kissing bugs are present faces some risk of catching the disease. However, dogs that spend large amounts of time outdoors, or those that spend time in outdoor kennels face an increased risk of Chagas.

What are the most common Chagas disease symptoms in dogs?

There are three distinct phases of Chagas disease in dogs and different symptoms may be exhibited depending on the stage of the disease.

Acute

Although dogs experiencing this phase of Chagas disease generally show no symptoms, you can sometimes see signs of the immune system fighting the parasite, such as:

• Pale gums
• Lack of appetite
• Diarrhea 

Latent

Lasting about four months, this stage too is generally asymptomatic. That said, in some rare cases sudden death may occur.

Chronic

It is in the chronic phase of the disease that symptoms typically begin to appear due to the increasing number of parasites present within the pet's heart. If your dog has reached the chronic phase of Chagas disease symptoms may include:

• Coughing
• Shortness of breath
• Lethargy or lack of energy
• Fever

Your veterinarian may also note a number of clinical signs, including:

• Irregular heartbeat
• Enlarged liver, spleen or lymph nodes
• Pale gums
• Distended abdomen

Many dogs are diagnosed with heart disease once they reach the chronic phase of Chagas.

How is Chagas disease in dogs diagnosed?

Since symptoms are common to many other conditions, diagnosing Chagas in dogs can be challenging.

Most dogs are diagnosed once the chronic stage has been reached. At this point, symptoms have typically become evident and there are sufficient parasites in the bloodstream to be detected through laboratory tests. That said, false positives can occur.

Sadly, sudden death can occur due to the strain on the dog's heart, at which time heart tissue samples can be taken to provide a conclusive cause of death.

How is Chagas disease treated in dogs?

At this time there is no definitive treatment for Chagas disease in dogs. In the early stages, antiparasitic and antifungal drugs such as Benznidazole, Ravuconazole, and Albaconazole may be effective, but not always. As the disease progresses these medications tend to have little effect.

Veterinarians generally concentrate on managing the symptoms of heart failure and helping dogs with Chagas disease achieve a good quality of life for as long as possible.

Note: The advice provided in this post is intended for informational purposes and does not constitute medical advice regarding pets. For an accurate diagnosis of your pet's condition, please make an appointment with your vet.