U.S. Homeland Security (DHS) dogs have been infected with a parasite. A new study finds that a surprising number of dogs working for the DHS are infected with the parasite Trypanosoma cruzi, which causes Chagas disease, an illness that can occur in both humans and dogs. The study analyzed blood samples from 1,660 federal working dogs that aid in tasks including border patrol, search and rescue, and detecting drugs and explosives, and found that about 7% of those tested, had antibodies against T. cruzi, which indicate an ongoing infection.