Chagas Disease In Dogs

A diagnosis of Chagas disease in your dog can be heartbreaking — it's incurable and potentially fatal. Also, because Chagas is zoonotic, thus transmissible to humans, dogs and cats who get the disease are often euthanized to prevent its transmission. The insect carriers of Chagas disease are dubbed the "kissing bug" for their habit of biting around victims' faces and mouths. Also known as chinch bugs, cone-nose bugs, or Chagas bugs, kissing bugs' scientific name is Triatoma sanguisuga, and they're members of the assassin bug or Reduviidae family and the only natural vectors of the disease. Rather than preying on insects like other assassin bugs do, kissing bugs have a predilection for feeding on the blood of mammals, birds, and even snakes, at night. Their bites are harmless, but if the insect is infected with the protozoan parasite, Trypanosoma cruzi, it can transmit Chagas disease to dogs and their people.

Three dogs are running out in the sunshine lawn.
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Where do you find kissing bugs and in which regions are dogs at risk of Chagas disease?

Dogs who live in South and Central America are particularly at risk for Chagas disease, but it's also reported in the United States in Texas, Louisiana, Georgia, South Carolina, North Carolina, Oklahoma, New Mexico, Virginia, California, Florida, and Maryland. Not exclusive to the southern states, it also occurs in Hawaii, Pennsylvania, California, and Colorado. Kissing bugs mostly frequent woodland areas, chicken coops, dog houses, and are also found under porches and woodpiles, and other areas where rodents live. They rarely invade homes unless it's a secluded property in a wooded area, but like all insects, they can slip through tiny cracks and crevices in any structure.

What is Chagas disease and what causes it.

Kissing bugs that are infected with the tiny, parasitic T. cruzi organism transmit Chagas disease through their bite or when a dog ingests the bug. It can also be passed from mother dog to offspring in transplacental transmission. Once the parasite is inside the dog's body it spreads by becoming intracellular, invading the bloodstream and attacking all the organs, including the brain and the heart, which are the most vulnerable to the disease with the most adverse effects.

What are the symptoms of Chagas disease in dogs?

Chagas disease can be acute, usually in dogs under two years of age, or chronic in older dogs, and some dogs are asymptomatic showing no sign of illness at all. In dogs who show no clinical signs, the undetected disease gives the parasites free rein, causing severe inflammation and degeneration of the heart over months or even years. An infected dog can suddenly die of heart failure.

Most cases of Chagas disease are outside the U.S., or reported by people returning from South and Central America.

The acute phase of Chagas disease persists for weeks or months. Symptoms may be mild or the dog may not show any clinical signs of illness. Acute symptoms include:

  • Swelling in the area of the bite.
  • Eyelids may swell.
  • Swollen glands
  • A rash may be present in the area of the bite.
  • Loss of appetite
  • Nausea
  • Diarrhea
  • Vomiting
  • Swollen glands
  • Swollen lymph nodes
  • Difficulty walking
  • Depression
  • Increased heart rate
  • Seizures
  • Enlargement of the liver or spleen

Chronic symptoms of Chagas disease are:

  • Weakness
  • Fainting
  • Increased heart rate
  • Fatigue
White Maltese dog at veterinarian's office.
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Diagnosis of Chagas disease and treatment.

If you think your dog is experiencing symptoms of Chagas disease, get her to your veterinarian for testing as soon as possible. Other dogs in the household, or litter, will need to be tested as well. The veterinarian will perform a thorough physical examination and review your dog's medical history. Lab tests will include a complete blood profile, urinalysis, serology, and an electrolyte panel which is used to indicate parasitic infection. An X-ray and echocardiogram will be used to identify pulmonary disease.

Some drugs have shown promise in treating Chagas disease in dogs in the acute stage, including Benznidazole which helps slow the development and progression of the disease. But, sadly, nothing has been able to suppress the disease in dogs.

How to identify a kissing bug and prevent your dog from getting Chagas disease.

Six skinny legs, a long, straight proboscis, thin antennae, and bulging eyes on the sides of their heads pretty much sums up the most outstanding physical characteristics of the mainly black or dark brown kissing bug, not so different from thousands of other bugs. Check them out on the internet and you'll find hundreds of excellent, close-up photos to help in your identification process. If kissing bugs do get inside your house, you'll likely encounter one at night, and hopefully not in your bed. Outside, kissing bugs lurk in wooded areas and many other places your dog likes to hang around so while prevention is key, it's not always easy.

Controlling the insects' access to your dog is the first line of defense since no vaccine for the disease exists as of 2018. Consider reducing lighting at night which attracts the insects. If your dog sleeps in a kennel, use protective, small-mesh screening making the kennel impervious to insect intruders. Eliminate breeding grounds for kissing bugs by removing wood piles and other dense brush in your backyard and entire property.