I hope you'll never have to deal with coccidia in puppies, because this tiny bug can make puppies sick. This is another protozoan that can colonize the dog's intestines and prompt diarrhea. Only the veterinarian can diagnose the illness, though, and prescribe the correct medication. But you can help prevent reinfection just by keeping the dog yard picked up. Learn more about this parasite in my most recent article about coccidia in puppies.