Hey Richard.
What is Chagas disease? I know those nasty bugs (down in C. America) can carry a super nasty parasite that attacks the heart! There is no cure and a transplant doesn't fix it as they're still in your system.
They bite around your mouth at night because they're attracted to the CO2, then they poop around where they eat. The bite doesn't transfer this parasite but people usually brush or scratch their face unknowingly and this transports the feces in to the bite spot and introduces the parasites.
Hopefully this is something other than Chagas!
I hope your dog's o.k.
Todd
Killed my first coral in 1991, have tried to do better since. Always tricky.