Animal Science

Freckles, my English Setter, has had skin problems for most of her young life. As a puppy she learned to lie quietly on her back while her belly was cleaned and treated.

The vet guessed that allergies, either to food or the environment, were to blame for Freckles' itchy, rashy skin. We had first ruled out some other skin conditions:

1. Pyoderma is what we initially thought caused the pustules on Freckles' belly. Using a combination of hydrogen peroxide and Zymox lotion helped clear up some of the pustules on her skin, but despite treatment, the skin remained reddish-orange and inflamed.
2. Mange or scabies is another skin condition that causes a similar response. The vet performed a skin scrape to check for mange; none was found and as a precaution we treated her with ivermectin for one month.
3. Yeast dermatitis, demodectic infection, and primary seborrhea can also cause a similar response.

Treatment for pyoderma and mange didn't improve the skin. Daily medication with Temeril-P and later with prednisone helped keep some of the itchiness at bay but she was still clearly uncomfortable. Benadryl was given on her worst days but just seemed to make her sleepy. Freckles licked off quite a bit of her hair as spring turned into a hot summer that was quite uncomfortable to human allergy sufferers.

It was time to take action. The vet suggested allergy testing.

Options for Canine Allergy Testing

I remember being allergy tested by dozens of pinpricks up and down my arms. When the vet first mentioned allergy testing for a dog I could not imagine a dog being very tolerant of that procedure! Skin testing is an option for dogs - they are usually sedated and clipped for the procedure. Luckily, there is another way.

Prior to 1990 allergy testing for dogs was conducted using the RAST/ELISA blood test. It was unreliable and had a high incidence of false-positives. Pets were uncomfortable during testing because no antihistamines or corticosteroids could be in the animal's system.

Luckily, allergy testing today can be conducted with a different type of test. Veterinary Allergy Reference Library (VARL) runs a serum allergy test that can identify allergens with better accuracy. A 3-5 mL sample of blood serum is needed. Two separate tests can be run - one for environmental allergies and another for food allergies. About 40 allergens are tested based on the pet's geographic location.

One of the vet techs at the office drew a sample of Freckles' blood and it was sent off to the VARL lab. The worst-case scenario was that Freckles could be allergic to everything. Having an allergy to everything can be treated with immune-suppressants. Just like humans can be allergic to pet dander, pets can be allergic to human dander. That didn't sound like a good option, either!

Part 2 of this blog series explains the results of Freckles' allergy test and the plan to help her feel better. This playful young dog is only about 1 ½ years old and I hope to get her back to normal within a few months!

Resources: Pets.WebMD.com; VARL

Related Reading on CR4: Dogs Can Get Acne - and Other Skin Conditions; Ivomec: Alternative to Pricey Heartworm Preventatives; Don't Feed That to Your Pet! (Toxic to Dogs - Part 1)