Diagnosing Dermatitis in Dogs

Dermatitis in dogs is an uncomfortable condition that can cause a number of skin disorders. The causes of dermatitis are numerous, making diagnosing the reason for a dog’s discomfort difficult at times.

Dermatitis Explained

Dermatitis is a term used to describe inflammation of a dog’s skin. The causes can be acute or chronic, and can be caused by:

  • Parasites
  • Allergies
  • Drugs
  • Toxins
  • Bacteria
  • Fungus
  • Yeast
  • Illness

A dog with dermatitis will lick, bite and scratch the area of irritation excessively. The area affected can look red, scaly or bumpy. Sometimes a dog will have hair loss in the area affected, which can also have thickened skin and lesions.

Diagnosing Dermatitis in Dogs

Since the causes of dermatitis are so vast, there are several different diagnostic tests that can be performed to find the root source of the condition. The first thing a veterinarian will do is a physical examination of a dog to see the extent of dermatitis and the parts of the body affected.

Skin Scrape

A common diagnostic test often performed is a skin scrape. This test is done with a surgical blade that gently scrapes the surface of a dog’s skin in search of mites or their eggs. The scrape will also allow a vet to collect samples of dry skin that will be studied under a microscope. Sometimes skin samples are also collected by sticking adhesive tape to a dog’s skin and studying any dry skin lifted off. A study of the skin will be performed to examine any lesions and infections, which can help determine if a skin infection was caused by yeast or bacteria.

Blood Tests

Blood samples may be collected to do a complete blood count and a biochemical profile. These tests will help a veterinarian have an idea of how blood cells are functioning and if there are any problems with a dog’s organs.

Other blood samples may be collected to test for allergies. Dogs can be allergic to things he comes in contact with, items in the air or even food. A test that can be performed on the skin to test for allergies is called intradermal allergy testing, which involves injecting a dog’s skin with a suspected allergen when a veterinarian thinks a dog has atopic dermatitis.

Allergy Food Trial

If it's thought that a dog has a food allergy, an allergy trial may be recommended. This process involves feeding a dog hypoallergenic dog food for a period of time. Then specific foods are reintroduced into the dog’s diet to see if his body reacts negatively to the ingredient. Once the ingredient that causes an allergic reaction in a dog is found, it can be eliminated from his diet so it does not cause further problems. It may take several weeks to find the culprit ingredient and for the dog’s dermatitis to clear up.

Once a veterinarian diagnoses the cause of a dog’s dermatitis, treatment can begin. It may take some time and patience to get to this point, but once treatment begins, a dog’s quality of life will greatly improve.