Bob's issues sound exactly like Sadie's issues - eye tears, loss of hair, infection in neck folds. I took her to a dermatologist. She was tested for allergies. Her biggie is dust mites - could she find a harder one to control?
I doubt it - the little stinker.
The dermatologist said there really wasn't a good test for food allergies except for the elimination diet. He, however, didn't feel her allergies were related to food.
As a side note, I had posted a pic of her eye on the site and folks thought it looked like a form of mange. It wasn't, however.
She gets medicated baths every two weeks now (after the issues settled down), gets her paws wiped as needed, is taking antigen shots, and was given meds to clear the infections of her face and neck.
Just before her eye issue, I had switched her to Costco's salmon and sweet potato food. She loves it! Because I felt it was that food that caused her eyes to water, I switched back to Orijen red. She, however, wasn't happy. Therefore I fed her a combo of both. Now, I'm weaning her off of Costco again and am trying other foods. If anyone in SoCal wants a half bag of the Costco food, PM me - and DON'T tell Sadie.
I would say see an allergist or dermatologist if you can. They cost more than the std. vet, but in the long run, you'll spend less, as they are used to dealing with skin/allergy issues. I went the other route with Rusty - decided to be much more proactive with Sadie.
The hair loss around the eye was directly related to the excess moisture in her eyes, which was related to the food she was eating. I can't figure out what is in the Costco food that causes her the issues, though.
I wish you the best.