Welcome to our weekly 'Ask a Vet from the SF SPCA' feature on 7x7.com. Dr. Jeannine Berger, DVM, DACVB is a board certified veterinary behaviorist who counsels guardians whose pets’ issues are beyond the scope of training. Think of her as a pet shrink at your service. Ask your own questions in the comments. 

Q: My dog has been itching like mad, but he is on flea meds and we've checked him for fleas. Nothing. Do you have any idea what might be going on?

A: As with people, it seems we see more allergy cases every year. Allergic disease is seen year round, but most commonly in spring and summer. Canine allergies are mostly characterized by skin problems, so we notice the dogs itching and scratching a lot. Allergic contact dermatitis is produced by physical contact with something that causes the skin to erupt; things like grass, irritating plants, or a sheepskin rug, for example. Symptoms are usually limited to parts of the body in contact with the substance, like the belly of a dog. Flea bite allergy speaks for itself and is undoubtedly the most common cause of allergic dermatitis in dogs and cats. Food allergy is an allergic reaction to one or more protein ingredients in the dog’s food. A diagnosis of atopy suggests an inherited tendency to be hypersensitive to a wide variety of substances, mostly things that are inhaled.  You will want to confer with your vet to determine what  might be the culprit.  There are a variety of treatments though none work perfectly in every case. Identification and elimination of the offending allergen is imperative, if possible, as it is with most food allergies or flea bite dermatitis. Veterinary dermatologists sometimes give a series of allergy shots to desensitize an atopic dog. And finally we have the whole medicine cabinet of drugs and treatments, including nutritional supplements, topical medications, anti-histamines, antibiotics, and anti-inflammatory drugs.