Quoting Kimberly Taddei:" He can be allergic to them. My DD is allergic to some kinds of dogs. We had a lab she was fine, we brought ... [snip!] ... we brought a beagle home and had the same reaction as you are describing. I would say regime them or get him allergy tested."
It is so odd, he is fine with the daycare's pug nose dogs but he has a slight reaction to my BIL's cats also, not hives but his eyes get itchy and watery and red, like he is with these chuahaha's (again spell???) this time though the hives look so bad but they don't seem to bother him like his eyes do. I don't want to make him suffer in any way so I am still trying to get a hold of the previous owner.