Ask the SkinVetMy 4-year old golden retriever Max scratches his armpits and chews on his feet all the time. It has gotten to the point that he wakes us up at night. He seems miserable and we can't sleep! We have been giving him Benadryl that was prescribed by our veterinarian, but it doesn't help. What can we do to make him more comfortable? -Marsha C., Glendale, CA
The two most common causes of chewing or licking the paws or scratching the armpits or chest are canine atopic dermatitis (also known as atopy), and food allergy. Together, we refer to these as allergic dermatitis or allergies. Depending on whether or not the itchiness (pruritus) changes with the seasons or not, your veterinarian or veterinary dermatologist may recommend a diet trial, which consists of changing to a food containing either completely new ingredients for Max, or one containing a “hydrolyzed” protein that is too small to cause an allergy. You should follow the recommendation of your veterinarian or veterinary dermatologist regarding the specific medically-formulated diet they recommend. Most veterinarians or veterinary dermatologists will recommend feeding the diet strictly for 8 weeks or more during a test (“trial”) period during which Max should eat only the recommended food or specific treats that might be recommended. Unfortunately, food allergy only explains the itchiness (pruritus) of a small percentage of dogs (and cats), perhaps 5-10%.
The most common causes of allergies (atopic dermatitis) are airborne grass, tree, or weed pollens, mold spores, or dust mites. Depending on how severe Max’s problem is (and it sounds pretty severe!), your veterinarian or veterinary dermatologist may recommend essential fatty acid supplements (marine fish oils), antihistamines (Benadryl is one of several we use in dogs), cortisone (glucocorticoids, steroids), Atopica® (cyclosporine), or allergy immunotherapy.
Antihistamines are more likely to be effective before the itching becomes severe, but in most cases they do not work well enough to keep our pets like Max comfortable. Cortisone (prednisone, prednisolone, Vetalog®, Depo-Medrol® and others) is ideally used only short term because of potential side effects, but may be the best option for certain pets and situations. Atopica® (cyclosporine) is a relatively new treatment (since 2003) for canine atopic dermatitis and is as effective as cortisone in clinical trials. It has fewer long-term side effects. I have found Atopica® (cyclosporine) to be very helpful to many of my patients since I began clinical trials with it nearly ten years ago. Allergy immunotherapy (allergy shots, hyposensitization) is given to sort of vaccinate pets against the things to which they are allergic (allergens). Your veterinarian or veterinary dermatologist may recommend allergy testing to try and find out to what Max is allergic. Allergy immunotherapy helps about 60-80% of dogs within a year. It does not produce quick relief of itching by itself, so it is often combined with other treatments. Medicated shampoos, rinses and wipes may also be helpful, especially if there are secondary bacterial or yeast infections on the skin.
Clearly you and your veterinarian have some decisions to make about how to manage Max, if in fact he has an allergy problem. I hope this information will help with your decision!
Wishing comfortable skin for Max,
The SkinVet, Jon D. Plant, DVM, DACVD
Board-certified veterinary dermatologist
SkinVet® Clinic, PLLC Lake Oswego, OR
Dr. Plant's answers in "Ask the SkinVet" are made without the benefit of a physical examination. Treatment should not be based on these answers only after an examination by a qualified veterinary professional. For more information, see the web site of the American College of Veterinary Dermatology.