Dog Allergies Treatment

My two shiba inus, my friends dog, and my moms dog, who have all been together for over a week have all just started itching. All of them have been treated for fleas and have had flea baths, no signs of fleas, is there anything else that it may be? The vet guessed Allergies, but is it common for all 4 of them to have it?

I’m trying to narrow down why my dog might be itching,biting and licking himself so much. I don’t believe it to be fleas and I’m thinking he might be alergic to the new food I bought him. What is the best food for dogs anyway? (Especially if they have allergies)

He has an allergy to fleas but we use flea medication and he has a flea collar, but he bites and licks himself and he has bald spots. It’s more than just regular shedding. The vet said he had an allergy to fleas and he was given cortisone shots and steroids. He takes medicine but even still what could be causing it? We’ve tried oatmeal baths. We also heard about corn oil in the food and tea tree oil on his coat but haven’t tried anything like that yet. Would that help?

not due to fleas
vets says it is skin allergies to grass
what is a good shampoo or lotion for dogs can you use baby shampoo on pets?

Movie Summaries

I just took my dog to the vet again because he develops staph infections from a contact allergy. This has been happening off and on for about two years. My vet and I are fresh out of ideas as to what he could be allergic to.
He is up to date on flea prevention and the vet found no fleas. It’s heavy winter here, and there isn’t a spec of grass to be seen anywhere. We do not use carpet fresh, febreeze, or any such products. He is not crated during the day and so he isn’t laying on dirty bedding all day. He has a dog bed, but never uses it. We do have carpeting (plush and berber), but it’s new within the last two months, and this has been going on much longer than that.
Any other ideas or suggestions as to what could be causing these allergies? The vet says she hasn’t seen a case this bad or frequent before. She says it is most definately a contact allergy, NOT a food allergy.