Diagnosing Pet Allergies

Pet allergies can occur in susceptible cats and dogs. Pets may be allergic to pollen, mold, smoke, chemicals, dust, synthetic materials, food or parasite bites. Diagnosing pet allergies can be performed in different ways, depending on the suspected allergen.

Symptoms of Allergies

An allergic pet will display symptoms that are similar to a cold:

  • Sneezing
  • Coughing
  • Difficulty in breathing
  • Weakness
  • Lethargy

The most common symptom of allergies is skin itchiness, red skin and even bald spots, where the pet has chewed or scratched for too long.

Overexposure to the allergens causing the symptoms can confirm the existence of allergies. However, in some cases it is difficult to pinpoint the exact allergen, so tests are needed.

Blood Testing

The most frequent blood tests are the radioallergosorbent test (RAST) and the enzyme linked immunosorbent assay test (ELISA).

These require a blood sample and are similar in methodology. The blood is tested to detect the presence of a certain IgE antibody that occurs in allergic pets when the blood is in contact with the suspected allergen. There are specific IgE antibodies for each type of allergen. Blood testing cannot give conclusive results for food allergies.

Intradermal Testing

Intradermal or skin testing is the most efficient method of diagnosing inhalant allergies. The test will provoke a small allergic reaction on the pet’s skin, after an injection with the supposed allergen. Some pets can have more severe reactions, such as anaphylactic shock. Note that this is rare, as the injected amounts of allergen are minimal.

Several allergens will be injected under the pet’s skin, and whichever one causes a negative reaction is the allergen. In sensitive pets, more than one allergen can cause redness on the skin. Skin testing is not an accurate analysis to identify food or contact allergies.

Food Trials

If blood or skin testing have shown no conclusive results, the pet must be allergic to a certain ingredient in his food. Food trials are conducted to detect the allergen.

The pet will receive a simple diet containing one source of protein and one source of fibers. This diet should be kept for 3 to 12 weeks. The pet’s diet will be modified gradually, by introducing a new ingredient each week or once in 2 weeks. The trials will be continued until an allergen is identified.

Diagnose Contact Allergies

Contact allergies can be diagnosed through elimination. If you suspect that your pet may be allergic to plastic, remove any plastic receptacles, such as food and water bowls, from the pet’s environment.

Remove one suspected allergen per week and you will notice an improvement of the pet’s condition after the real allergen is removed.

Diagnosing the allergen is the most important step in treating the allergies. Depending on the allergen, your vet will recommend medication (antihistamines or corticosteroids) or immunization therapy. The allergen must be removed from the pet’s environment, if possible. A special diet can be prescribed for allergic dogs to reduce the reactions.