Most people first notice that their dog is allergic to something via digestive upset or a dermatological reaction. These dog skin allergies can be as obvious as clumps of hair falling out, or as moderate as slightly increasing scratching.

A skin ailment on your dog is a clue to take him or her to the vet. Because some of these problems are related to problems that you cannot solve without medical expertise and treatment, your dog will need to be examined by a vet. A diagnosis of allergies is usually made after ruling out other problems, and then you can start home treatments (along with any your vet prescribes).

Just because the effects show on the skin or coat does not mean that your dog was exposed to it that way. Some allergens are topical, such as rubbing on a bush that the dog is allergic to, but others are related to diet or environment. A dog that is allergic to his or her food may have dry, patchy skin or other dermatological symptoms.

Removing potential allergens from your dog's diet and environment is usually the first step in both treating him or her and figuring out what he's allergic to. If the problem resolves itself when common allergens are removed from the dog's life, then you can start reintroducing them one or two at a time, in order to figure out which ones elicit a reaction. Changing to a low-allergen dog food is especially important during the removal phase, because many regular foods contain wheat or other grains that are common allergens in both dogs and people.

In terms of the environment, removing fleas is important, because many dogs are allergic to flea bites. If the dog is not already being treated with a flea preventative, he or she should be started on one. And the home should be treated for fleas if this problem is suspected, because most dog treatments only prevent fleas from reproducing on them, not biting them a few times. Infestations are effectively prohibited this way, but those few bites can be enough to cause allergic reactions.

Though most allergens that come from the air manifest as respiratory problems, it is worth cleaning out the home if your dog displays non-specific allergic symptoms. This means removing as much dust and air pollution as possible by vacuuming, dusting with a dust-trapping cloth or duster, and using an air purifier if you have one or are willing to get one. This will lessen any reactions to dust, mites, pollen, and other airborne allergens.

Some dogs are allergic to things that it isn't possible to remove sufficiently from their environments. Allergy medications can be prescribed by your veterinarian if this is the case for your dog. But avoiding the allergen is the best treatment, so going through your dog's routine, everything he or she eats and is exposed to, and eliminating whatever potential sources of allergens there might be is the best option.

Reactions to dog skin allergies include itching, pain, and other discomfort. In order to alleviate this discomfort while you are treating the dog, your vet might prescribe some kind of cream, bath, or medication. Remember to follow your vet's instructions, in order to make your pet as comfortable as possible while you are treating the underlying issue.