By Virginia Clemans, DVM
Does your dog itch? Scratch? Chew? Rub? Shake? Scoot? Is it driving you and your dog mad? Just like in people, itching in dogs can be caused by a lot of different things. The most common cause is something called atopic dermatitis, also called “inhalant allergy.” When dogs are allergic to dust, pollens, mold, mildew, insects, or animal or human dander, instead of suffering from hay fever, they get itchy skin. When they scratch, the bacteria normally present on the skin becomes driven into the deeper skin layers and causes an infection. Sometimes dogs even develop an allergy to the bacteria itself and this causes even more itching! Those little red bumps you may see on the skin are probably pustules (little pimples) caused by the bacteria.
Fungal infections like ringworm can affect the skin and nail beds, causing itching and chewing of the feet. Yeast infections of the skin and ears also can be very itchy, and cause a very characteristic odor.
Some other causes of itching include “contact allergy” – an allergic reaction to the detergent used to wash bedding, for example, or allergies to materials like wool. But this type of allergy is fairly rare in dogs. Dogs can become allergic to fleas, however, and even one flea bite can become very itchy. There are some skin mites that can cause itching as well. A food allergy (allergy to proteins contained in food) can be the cause of itching in some dogs. Dogs can have several different types of allergies all at once (bacterial, food, inhalant, etc.), making the causes more difficult to determine.
Certain diseases can cause skin problems or make existing skin problems worse. Just like people, dogs can have thyroid problems. In dogs, a condition called hypothyroidism (not enough thyroid hormone produced) can make the skin more likely to have allergy and infection problems. Thyroid disease can cause the skin to become oily or flaky, and the hair coat to be dull, thin, and brittle.
Blood tests, skin scrapings, and fungal cultures all help determine the exact cause of a skin problem. Once we know what the cause is, an appropriate treatment can be prescribed and the dog can be on the way to comfortable, healthy skin. Various combinations of treatments may need to be tried before the right combination is found.
Medications such as antibiotics, antihistamines, anti-inflammatories, and fatty acid supplements may need to be given by mouth until the problem is under control. Some medications may need to be continued long-term.
Bathing is very important to maintain healthy skin. Regular baths with a medicated shampoo can reduce the number of bacteria on the skin. Baths remove dead hair and skin cells that aggravate skin conditions.
If a food allergy is suspected, a diet change may be in order as well. Try switching your dog’s food to one that contains a type of protein that your dog hasn’t been exposed to yet. Beef, lamb and chicken are found in most dog foods, so this means switching to a dog food containing a “novel” protein, such as fish, venison or rabbit. Talk to your veterinarian about which food to switch to and where to obtain this type of food.
The skin cycle lasts approximately 21 days – it takes that long for old skin to be replaced by new skin. So, any treatment that you attempt may not show results until a three-week period has passed. This is especially true for diet changes and fatty acid supplements. Be patient! Find the cause, follow the treatment exactly, and get your dog’s skin back on the track to health. Beauty is only skin deep, but healthy skin makes you and your dog feel better!
BEST FRIENDS Animal Society • 435-644-2001 • www.bestfriends.org
Dr. Virginia Clemans was Best Friends’ chief veterinarian from 2001 to 2004. She now resides in Salt Lake City, where she is chief of staff for the Utah County Fix, a low-cost, high-volume spay/neuter and vaccine clinic sponsored by No More Homeless Pets in Utah, Maddie’s Fund and Best Friends Animal Society.
