That is so sad. I hope the puppy recovers!

Just make sure you change your clothes/shoes when you come home and wash your hands/face up good before handling your own dogs.

As for getting him to eat, I'm not as familiar with getting a reluctant dog to eat, but you might want to try:
Cooked skinless chicken or turkey
Boiled plain rice
Microwaving the food so he can smell it good

Good luck in your efforts to help this puppy!