Not to start an argument but this may not be the case for all dogs. Biting a certain areas may not mean one thing..bathing once a month is ok for some, oil on the food is reccommended by many vets.. Food, supplements, bathing, allergies..all depends on the dog. This site has been very helpful with an abundance of information, but to say one thing is absolute is not ideal in my opinion. I would talk to your vet and other vets as well to see what the general consensus is.dry skin is mostly caused by food allergies. putting canola oil or vegetable oil on kibble DOESNT DO ANYTHING or dry skin and itching. what are you feeding your dog? he could be allergic to something in his food and also if you bathe your dog more than once a month you could be drying out his skin. you shouldnt use additives to your dogs kibble UNLESS your vet gives the okay to do so. if he bites at his butt area and his feet area it is most likely a food allergy. try changing brands or go to a raw diet made by Natures Variety it clears up skin problems and dogs with tear stains and its pretty cheap.