I agree with the others. Definitely make an appointment to take him to the vet. It's just peace of mind and you will feel so much better after you know that he is 100% healthy or what is wrong with him.
Diamond had coccidia when she was a puppy and that can cause diarreha. They usually give you an antibiotic for it and it works within 5 days to a week.
Good Luck and let us know what happens.
__________________ Proud mommy of Diamond |