Thank you for your input! I'll make sure to call my vet later.
I agree, first have him checked out by a vet to find out the dosage. Poopdeck has had a few reactions to ...I don't know what ..and the vet said as long as it was "Diphenhydramine hydrchloride" then it was ok. However you still have to check with your vet to find out dosage.