Nutritional management of allergic skin disease: a roundtable discussion (Sponsored by Royal Canin)
Apr 14, 2010
CUSTOM VETERINARY MEDIA
Karen E. Felsted, CPA, MS, DVM, CVPM
In 1996 Dr. Felsted graduated from the veterinary college at Texas A & M University and practiced both small animal and emergency medicine for three years. For the last ten years she has provided financial and operational consulting services to veterinarians, most recently with Brakke Consulting and Gatto McFerson CPAs.
Dr. Felsted joined the National Commission on Veterinary Economic Issues as Chief Executive Officer in June 2008. She has written an extensive number of articles for a wide range of veterinary publications and speaks regularly at national and international veterinary meetings. She is a founding director and current member of VetPartners, a past member of the Veterinary Economics Editorial Advisory Board, and the current treasurer for the CATalyst Council.
Dr. Karen Felsted: I am Dr. Karen Felsted. I will be the moderator. Today, we are going to discuss diagnosing and treating adverse food reactions. Lef s start by talking about how frequently you all see these kinds of cases.
Dr. Garfield: In food allergic patients, the symptoms are always non-seasonal. About a third of our patients in the Dallas area start out with year-round or perennial symptoms. My guess is that about 20 percent of those with perennial symptoms are food allergic. This would equate to about 6 percent or maybe as high as 10 percent of all the allergic patients we see.
Dr. Strauss: I would agree with that for dogs. I think it is a pretty significant difference with cats. I would say food allergies or adverse food reaction in cats represents about 40 percent of pruritic feline patients. I think there is a big difference between the dog and the cat.
Dr. Fadok: I would be willing to wager 10-15 percent of the dogs we see have food allergy or an adverse food reaction. I suspect there is a subset of those dogs that are atopic as well, maybe as much as 50 percent based on some data from Linda Messinger's practice at Veterinary Referral Center of Colorado (VRCC). I would also estimate that 10 percent of our atopic dogs have food allergies too. This can make sorting out the contributions of food compared to environmental allergens quite difficult!
Dr. Felsted: So how do you all go about diagnosing adverse food reactions? What clinical signs make you suspect a food allergy?
Dr. Garfield: Symptoms of food allergy and atopic dermatitis are indistinguishable, although food allergic individuals tend to be more severe than atopic patients. Symptoms are always perennial and tend to be less responsive to symptomatic treatment. When we are trying to control secondary infections and calm itch with antihistamines and even with steroids, food allergic patients tend to not respond as completely or as quickly to those medications.
Dr. Liska: I would agree.
Dr. Strauss: I would just point out that there is very significant overlap in the clinical presentation of food allergic individuals and atopic individuals. There is not any reliable distinguishing clinical sign to differentiate those. You really have to work through the diagnosis to come to the conclusion of a food allergy.
Dr. Felsted: Any difference between dogs and cats?
Dr. Strauss: In canine patients, pruritus, of course, is the main thing that we see. I see erythema in the ears, axillae, feet (interdigitally, palmar and plantar surfaces), around the eyes, ventral abdomen and under the tail. These patients have significant pruritis. With cats the most common presentation is miliary dermatitis.
Dr. Fadok: I see 3 distinct patterns in dogs: itchy ears only, caudal half of the body and an atopic dermatitis-like pattern (foot and axilla chewers, face rubbers, etc). The cats I see tend to exhibit severe head and neck pruritus, generalized itching, or eosinophilic plaques and hair pulling.
Dr. Strauss: I would be interested to hear what the rest of the group thinks about concurrent GI signs. The incidence of concurrent enteric disease with our food allergic patients, I think, is pretty high. Probably about one-third of them have some GI signs in my experience. Would you guys agree with that?