A Vet, a Physician, and an Unwanted Dog
On a hot, South Texas summer afternoon in 2007, Roy Madigan, D.V.M. and Director of the Animal Hospital of Smithson Valley, got a call from the local humane society. “Can we bring a dog right over? Something’s terribly wrong.” A 1-1/2 to 2-year-old Pointer mix, Max had been a shelter resident while he hoped for an adoptive owner. When he arrived at the clinic, his heart rate was over 220 (a normal heart rate is 60 to 140). He had severe arrhythmia. He was collapsed on the ground and panting heavily. The hospital team immediately started an IV with medication and oxygen to bring his heart rate down. His blood work was normal, X-rays were normal, but his EKG looked like a scrambled TV. Roy was at the clinic until late that night trying to reverse the arrhythmia. He left after replenishing Max’s drugs and praying. When he returned in the morning, Max had died.
“I was so frustrated,” said Roy. “I didn’t know why he had those symptoms. I was frustrated that we couldn’t get him healthy and frustrated that he died.” After conducting a necropsy, it was clear that he had serious heart disease, but it wasn’t at all clear why. The hospital sent off tissue samples to Texas A&M University, the leading veterinary school in Texas, with a big question mark. It was more than three weeks before vets at Texas A&M called Roy to say that they were having a meeting on the samples, because they didn’t know what caused the problems either. Roy vaguely remembered something about Chagas disease and heart problems from a day in his parasitology class in vet school. He’d slept through part of the class because the topic was malaria and Chagas disease and “we don’t have those diseases” in the U.S. After doing additional tests and special stains of the tissue, the A&M team found the Trypanosoma cruzi parasite in the heart tissue, which meant Chagas disease.
“They were floored and we were floored,” said Roy. “How many other dogs out there have it? Do I see this every day and I just don’t know it? What’s going on here?”
The Same Story with a Different Ending
Unbeknownst to Roy, in Venezuela Alberto E. Paniz Mondolfi, M.D. was treating a human patient with Chagas disease and leishmaniasis, another parasitic disease. He prescribed a commonly used drug to bring the patient’s arrhythmia under control. At the same time, laboratory clinicians were investigating a second drug that is frequently used to treat fungal infections. Dr. Mondolfi decided to also prescribe the second drug. The patient’s arrhythmias were reversed, he started feeling better, he was able to leave the hospital, and within six months, the Chagas infection was gone. Normally, the patient would have died. In March 2009, Dr. Mondolfi published a paper in Venezuela about the case, which went largely unnoticed.
Four months later, an 180-pound Irish Wolfhound came into Roy’s hospital with a swollen leg. After extensive testing, the dog was diagnosed with Chagas. Roy began researching treatments for Chagas, and while scouring the Internet, found Dr. Mondolfi’s paper. He reached out over email, and the two doctors formulated a treatment plan for the Irish Wolfhound based on Dr. Mondolfi’s experience with the human Chagas patient. The dog got better and was cured.
Tremendously excited, Dr. Mondolfi urged Roy to begin testing the formulation more extensively. Roy and his team began testing dogs from several vet clinics around San Antonio. About every three months, he would pack blood samples and send to Dr. Mondolfi’s lab in Venezuela, which specializes in testing for the T. cruzi organism and antibodies. But with the political situation in Venezuela, each batch of samples faced an uncertain fate. One batch was captured by rebel insurgents, who drove off into the jungle. Customs agents demanded bribes and refused to allow samples through. Twice, the country’s power grid failed shortly after samples arrived at the lab, and staff scrambled to find a generator that could power a tiny refrigerator long enough to preserve samples until power was restored. The final batch arrived during a rebel assault on the building where the lab was housed. As rebels hurled Molotov cocktails into the building, Dr. Mondofi’s team completed the final test run before the building burned down.
Dogs, Monkeys, and a Walrus
In spite of the challenges, the data was promising. Roy launched a long-term study of Chagas disease in military working dogs at Lackland Air Force Base in San Antonio. The data got better. They connected with a primate facility where some of the Macaque monkeys were dying suddenly. It was Chagas disease. After adjusting drug dosages, Roy’s team was able to cure many of the monkeys.
In 2014, Roy got a call from SeaWorld. While doing routine blood work on a walrus, the SeaWorld technician identified something strange and sent the sample to Texas A&M. After running inconclusive tests, Texas A&M told SeaWorld about Roy and his work with Chagas. They sent another sample to Roy and it tested positive for Chagas. The disease had never been seen in a walrus before, and SeaWorld wanted to treat it. How much drug do you give a 1,000-pound walrus when you’re usually treating dogs? They tested different dosages and successfully treated the walrus for 12 months, after which he tested free fro the disease.
Next Stop, A Cure for Humans
The formula for veterinary use was patented in 2016. In 2017, Roy conducted a rigorous study at Stanford University, using the university’s innovative approach to growing live, beating human cardiac cells in vitro. Chagas disease was introduced into healthy human heart cells and treated with the formula and benznidazole, a drug that has been used to treat Chagas patients in other countries. The results were astounding. The treatment successfully cleared the parasite more than 95% of the time within a few treatments. The benznidazole succeeded less than 60% of the time.
At home in Texas, more local animals are being identified with Chagas disease—dogs, sea otters, a bear, monkeys, and a horse. Wherever triatomines (kissing bugs) live, so does the potential for Chagas disease. It’s time for a treatment.
What is Chagas and What Should I Look For?
Chagas disease is caused by the parasite Trypanosoma cruzi, and it infects more than 13 million dogs in the U.S. T. cruzi is spread by triatomine bugs, also known as kissing bugs. They are endemic in the southern U.S., Latin, and South America. Symptoms include:
- Depression or lethargy
- Lack of appetite
- Weakness or difficulty walking
- Increased heart rate
- Swollen lymph nodes, liver, or spleen
Have Dogs Tested for Chagas
If you are concerned that your dogs are exposed to kissing bugs, contact your veterinarian and have your dog tested. An Indirect Immunofluorescence Assay (IFA) test—is used to analyze your pet’s blood for antibodies against the parasite.
About Vida Pharmacal
Vida Pharmacal develops, markets, and distributes pharmaceuticals designed to treat rare and Neglected Tropical Diseases (NTDs) for human and veterinary patients. Founded in 2017, the company has developed the world’s first treatment for Chagas disease in humans and canines. Vida Pharmacal is headquartered in Spring Branch, Texas. For more information, email us at firstname.lastname@example.org.