We've been trying to get to the root of my dog's allergies for about a year now. It's a real bummer! We thought it was food related so we switched his food several times. Chico does really well on DVP duck and potato and kirkland lamb and rice (just like Havoc's dog). I don't think Chico's is food related though. He gets really bad after he's been running through grass. Anyways, I was gonna say that you can give up to 1mg. of Benadryl per lb. of body weight. Dogs can take alot more than humans. If Chico is having a bad itchy attack, I give him 100mg. Also you should try some Microtek spray. That stuff really seems to relieve the itching. I notice that the skin around Chico's face gets really pinkish red after he's been running around alot.