Chagas Disease Services

Chagas disease is caused by Trypanosoma cruzi, a protozoal parasite primarily transmitted by insects known as “Kissing Bugs.” Kissing Bugs and T. cruzi have been in the southern USA for many years but the number of infected dogs is growing rapidly. Since 2019 Pan American Vet Labs has identified more than 1000 dogs in Texas, Oklahoma and New Mexico which tested positive for Chagas disease.

Dogs become infected through contact with feces of “Kissing Bugs” which can happen when the bugs take a blood meal from the dog, or when dogs eat infected bugs. Dogs can also be infected via in utero transfer from infected female dogs to their pups prior to birth. Once infected +/- 25% of dogs will develop clinical disease, the remaining 75% remain clinically normal. However, these dogs give a positive blood test and can spread the infection to bugs that take a blood meal or via in utero transmission from female to unborn pups.

When dogs acquire this infection, the parasites circulate in the blood for a few weeks then invade various tissues. The heart is most commonly infected, but the intestinal wall and the esophagus can also be infected. In those dogs that develop clinical disease a strong allergic immune response is found, while those that remain clinically normal do not develop an allergic reaction to the parasite. This allergic reaction causes severe damage to the infected tissues.

Conventional treatment involves administering chemical medicines to kill the parasite and has a poor success rate. PAVL is investigating a novel Immunotherapeutic approach designed to change the allergic immunity found in clinical disease to non-allergic immunity. When this is successful the patient becomes clinically normal but likely remains infected, like the 75% that never get sick.