Why is my puppy vomiting and having loose stools after a food change?
Poor Theo! Given that he was throwing up the Blue Buffalo (BB) food, but now isn't vomiting on the Simply Nurish, I would suspect that the BB isn't agreeing with his stomach. As for his poop, changes in diet can lead to looser stools. Even though you did half and half to help him switch, typically it's better to do 1/4 new food and 3/4 old food to start. To help Theo with his diarrhea, I can give you a home remedy to try. Withhold food for 12-24 hours, then feed a bland diet of boiled white meat chicken (no bones) and white rice in small amounts several times a day for a couple of days. Then slowly add back in his normal diet.
I would also recommend getting Theo's vaccines done ASAP if he's seven months of age. I see that you are in Utah, and a rabies vaccines for all dogs is required by law, so it is important that he get that vaccines plus the DHPPi combination shot (distemper, parvovirus, hepatitis, parainfluenza) once he is feeling better. I would wait until the diarrhea has cleared up before getting him those vaccines. I hope this helps :-)
Updated on September 23rd, 2025