Just Ask the Expert: How should I treat a dog that is allergic to only house dust mites?

Dr. Spiegel welcomes dermatology questions from veterinarians and veterinary technicians.

Click here to submit your question, or send an e-mail to vm@advanstar.com with the subject line "Dermatology questions."

Sometimes I find that a dog with atopic dermatitis is allergic only to mite mix and house dust—granted, house dust is mainly mites. It causes problems for me in making up the vaccine. Too much allergen in the vaccine makes the dog itch after the injection, and too little does not work or does not last long enough. How do you handle dogs that are markedly allergic to these two allergens only or almost only?

A. In my experience, it is rare to get only one or two positive reactions with an intradermal test in veterinary patients. However, it does occur. When I get test results with only a couple of positive reactions, I often suggest that a serologic test be done for comparison (or vice versa). The other option is to wait six months and repeat the allergy testing.

Ian Spiegel

If the results still show only a couple of positive reactions, you can still initiate allergen-specific immunotherapy. I usually do not exceed 1.5 ml of any one particular allergen regardless of the concentration. Thus, for a 10-ml volume, I would add the two allergens for a total of 3 ml and then add 7 ml of saline solution.

If the problem is truly just house dust mites, I might discuss with the client other possible means of dealing with the problem. I usually recommend clients use an acaricide, such as Acarosan (Bissell), to clean up the environment and add house-dust-mite-impermeable bedding covers to the dog beds and even to their beds. I also often recommend that owners consider purchasing high-efficiency particulate air filters. And, depending on the individual case, I might even consider prescribing an alternative such as cyclosporine.

Ian Spiegel, VMD, MHS, DACVD

Veterinary Specialty and Emergency Center

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