Itchy Dogs

November 16, 2008 by Dog Service Network
Filed under Health

“Over 75 percent of my cases are dogs that scratch excessively,” says Dr. Kinga Gortel, veterinarian and former dermatology resident at the University of Illinois Veterinary Medicine Teaching Hospital at Urbana. “These dogs may have an itchy rash, they may have hair loss from scratching, or they may just scratch incessantly. We see more itchy dogs than itchy animals of any other species, including cats and horses.”

There are many conditions that cause dogs to scratch. “The three biggest ones are parasites, allergies, and skin infections,” explains Dr. Gortel.

The most common parasite that will make a dog scratch is the flea. Even with the current excellent flea preventatives on the market, a lot of dogs suffer from fleas because owners don’t use the products. Correctly applied treatment, such as a once-a-month topical application, is a simple and effective way to protect dogs from fleas. Even indoor dogs should be treated because they can pick up fleas in the backyard or in parks. Mites are also parasites that cause dogs to scratch. Parasites can cause an itch so intense that large areas of hair are lost from scratching.

Allergies are another frequent cause of scratching in dogs. Fleas are again the most common culprit in many parts of the country. Most dogs with fleas will scratch to some extent, but a dog with flea allergy is miserable after only one flea bite. The next most common allergies are environmental-due to seasonal pollens, molds, and insects-and non-seasonal allergens, such as house dust and house dust mites. Environmental allergies are similar to those people have. However, people usually sneeze and get a running nose
and eyes, and dogs usually itch. Food allergies, caused by one or more ingredients in the dog’s diet, are less common but can be more severe.

“The symptoms of environmental allergies can be treated with anti-inflammatories and shampoos. However, we recommend allergy testing and hyposensitization because they are the only real way to address the underlying disease,” explains Dr. Gortel. “Most allergens can’t be avoided because they are airborne and are everywhere.”

Intradermal skin testing is the most accurate method of identifying a dog’s sensitivity to allergens. Minute amounts of different allergens are injected into the skin, each in a different site, and the skin is watched for a reaction after 15 and 30 minutes. “Skin testing is not difficult, but experience is needed to read the reactions correctly,” says Dr. Gortel. “The animal has to be off certain medications, such as steroids and anti-histamines, to have an accurate test.” Blood tests can also be used to identify allergens.

Once the allergen is identified, it can be avoided, if possible, or the dog can be hyposensitized. Hyposensitization is accomplished by giving the dog frequent exposures to increasing amounts of the allergen by skin injection. The immune system then “relearns” that these things are harmless.

Bacterial and yeast skin infections are the third major cause of scratching in dogs. Such infections usually occur when the skin’s immune system is compromised by stress, illness, or allergies. The offending bacteria or yeast is often an organism that is normally found on the skin but has grown beyond its usual low numbers. Bacterial infections may look like small bumps on the skin. Yeast skin infections may be smelly and greasy as well as itchy. These infections are easily cleared but the primary stress or illness must be treated.

“Often scratching is due to combinations of these three causes, and it is important to address and treat each one separately,” says Dr. Gortel. “Dogs don’t have to be tormented by constant itching.”

For more information on pet care, contact your local veterinarian.

Theresa A. Fuess, Ph.D., Information Specialist
Reprinted with permission by the University of Illinois College of Veterinary Medicine, http://www.cvm.uiuc.edu/petcolumns/showarticle.cfm?id=139