If you don't think he's getting better; don't hesitate to take him back to the Vet. Make sure he is at least drinking water because at his young age; diarrhea and dehydration could take him down very quickly.
Is this Purina EN? My Westie is on this for tummy issues right now and it is not helping him at all. I felt like the Iams Low Residue helped him a lot more. I'm about the call the vet back myself.
__________________  Mommy to Lucy, Ringo, and Matthew |