[From Tufts November 2011 Issue]
My 4-year-old Lab-golden mix, Sam, has suffered since puppyhood with severe itching. He would lie around whining and crying all the time while scratching and biting himself. He was living in pure misery. My vet’s first attempt at help was Benadryl. When this did no good at all, we went to prednisone, still no help.
Finally, we got cyclosporine for him, and this has helped considerably. Sam does not cry all the time like he used to but still has a lot of itching. He mostly bites and licks at his feet now. I am very concerned, though, about the use of the cyclosporine because it lowers the immune system. Please advise me on this and give me any suggestions you can on any other treatments I might try. Thanks for any help you can give me.
For animals with very intense itchiness, it is absolutely critical to evaluate for parasites, adverse food reactions, atopic dermatitis (environmental allergies) and surface bacterial and yeast infections. One cause of profound itching is the scabies mite, Sarcoptes scabiei. It can be very challenging to find even with a diligent veterinary search.
In those instances, it is worth doing a parasite-control trial that will eliminate such a parasite over a course of weeks. Sarcoptic mange due to scabies mites can also be contagious to people as well as other animals, so treatment may be considered by your veterinarian for public health reasons, even if the mites cannot be definitively demonstrated on the dog.
Another itchy condition that is not very responsive to prednisone is an adverse food reaction, which can be a true allergy or some form of intolerance to dietary ingredients. The diagnosis is made by feeding an elimination diet trial for a minimum of eight weeks. It consists of protein and carbohydrate sources to which the dog has never been exposed.
These diets would be available from your veterinarian, or a home-made version using novel ingredients might be suggested, but it is very important that no other foods, treats or flavored medications be used during the trial period.
Any surface infections need to be controlled, since they can contribute to itchiness, and if this problem is actually due to environmental allergies, then allergy testing and immunotherapy (allergy shots) might be considered as long-term strategies after parasites and adverse food reactions have been eliminated as possibilities.
Environmental allergies, also known as atopy or atopic dermatitis, are very common in dogs but are typically very responsive to corticosteroids such as prednisone, so this could be an exception to the rule, a combination of problems or a non-atopic condition, such as those mentioned earlier. Fortunately, if your veterinarian is having problems confirming a diagnosis, then a referral to a dermatologist can be arranged that might help get to the bottom of these issues.
Lowell Ackerman, DVM, DACVD