hey. My father has major allergy issues to everything except foods. He says it is partly due to his occupation. He is a carpet installer and from ripping up other people's carpets that have gone through some many torturous events... (urination, dust invasion etc.) his allergies seem to worsen. We have three dogs and he always has trouble being around them for more than two seconds! literally- however whne we visites the pet shop in our local mall he took a few dogs out to play with and were fine with them... We thought is could be the dog's diet but each dog has a unique diet in our family and each causes him to become very irritable, water eyed, sneezing, coughing etc... what can we do? what could it be?

thanks!