Dear Kara: Food allergies (Sponsored by Hill's Pet Nutrition)

What are the clinical signs of food allergies or food intolerance in dogs and cats?

A variety of clinical signs can manifest from food allergy or food intolerance. In dogs and cats, they can include itchiness, skin lesions, skin and ear infections, and gastrointestinal problems. In cats, clinical signs can also include miliary dermatitis, self-inflicted hair loss and skin scratches, ulcers of the lip, and eosinophilic plaques.

I don't understand the importance of foods with hydrolyzed protein. How do these foods compare to therapeutic foods that use an uncommon protein source?

Hydrolyzation is an innovative process that simplifies the nutritional management of pets with food allergies. Hydrolyzation breaks down protein molecules so that they are too small to be recognized by the pets immune system avoiding an allergic reaction. Adverse food reactions account for 10% to 20% of allergic responses in dogs and cats and can be managed by feeding a hydrolyzed protein food.

Uncommon protein sources, as you call them, are also known as novel proteins. The theory is that a food is formulated to contain a single novel source of protein. If a pet has never been exposed to this unique protein source, its immune system may not have developed a sensitivity to that protein source. Both nutritional management approaches are valid, but healthcare teams typically recommend hydrolyzed foods in cases of adverse food reactions.

Food for Thought

If we suspect a patient has food allergies, should we always start with Hill's® Prescription Diet® z/d® Low Allergen pet food or should we consider Hill's® Prescription Diet® z/d® ULTRA Allergen-Free in some cases? Should we immediately change to z/d or do it gradually?

This question depends on the case. If you have a dog that has been on numerous food trials or novel protein sources, the veterinarian is likely to recommend z/d ULTRA Allergen-Free. To help ensure a successful transition to the new food, recommend that the client gradually increase the percent of the new food in the pets food bowl and decrease the percent of the old food over the course of seven to 10 days.

Can puppies get enough nutrition from only Hill's® Prescription Diet® z/d® Canine pet food? One of our clients struggles with keeping food separate from her new puppy and her older, food-allergic dog. Can she put them both on z/d?

Prescription Diet z/d Canine is not recommended for puppies. Puppies have specific needs for their growing bodies, and Science Diet® Puppy pet foods are formulated to meet the needs of high-energy puppies up to 12 months of age. Remember that z/d is a therapeutic food recommended by a veterinarian for a specific condition. Therefore, its extremely important that the food-allergic dog eat only the z/d as recommended.

It's not impossible to feed the two dogs separately; however, it requires effort from both you and the client. To achieve compliance, you must educate the owner about why the older dog needs the therapeutic food and why the puppy needs the Science Diet Puppy food. This means that you—a compassionate and knowledgeable healthcare team member—must set aside time for client education, start an open dialogue that includes written and verbal instructions, follow up with the client, and provide constant encouragement.

How would you educate a client who buys a non-therapeutic venison and rice food rather than the Hill's® Prescription Diet® d/d® Canine pet food her dog needs? I keep repeating that a non-therapeutic food is not recommended. The other day the client asked about the difference between non-therapeutic and therapeutic foods—and I didn't have an answer.

First, having the dog on a therapeutic food allows you to follow up on the dog's condition. Second, a therapeutic food, such as Prescription Diet d/d, ensures the food contains one protein source and one carbohydrate source to help avoid common food allergens. Some commercial wellness formulations claim one protein and one carbohydrate source but actually have multiple sources. Third, d/d Canine has been clinically shown to help reduce itching and scratching.

Finally, d/d contains enhanced levels of omega-3 and omega-6 fatty acids, including eicosapentaenoic acid (EPA), to help nourish the skin, manage inflammation, and support the skin's barrier.

Is it possible for an allergic dog to develop allergies to d/d® pet food over time? We see a dog that has done well on d/d for years but hot spots suddenly appeared. Is it time to switch foods?

Many conditions can mimic adverse food reactions (and vice versa), including reactions to ectoparasites (fleas, mites, lice), atopic dermatitis, and bacterial or yeast (Malassezia) skin infections. Complete evaluation by the veterinarian is key. However, the potential for the pet to become allergic to the novel protein source does exist. Some healthcare team members may try a different novel protein source, but the recommendation is to nutritionally manage the pet with a hydrolyzed food, since this eliminates the potential for an allergic reaction.

We used to recommend a dried salmon treat for cats and dogs with food allergies. Now that we offer hypoallergenic treats that go with the therapeutic foods, should we switch patients from dried salmon to hypoallergenic treats? The switch makes us feel awkward because we made the salmon recommendation first.

I understand the apprehension when changing your previous recommendation; however, this illustrates that your healthcare team is up-to-date on cutting-edge information in the veterinary profession. Owners have a strong desire to treat their pets, and Hill's® Prescription Diet® Hypoallergenic Treats for both dogs and cats allow owners a tasty, healthy, and rewarding way to treat their pets with food allergies or inflammatory skin conditions in a formulation similar to Prescription Diet® z/d® pet food. The treats virtually eliminate the potential for adverse food reactions with clinically proven hydrolyzed protein technology. Prescription Diet Hypoallergenic Treats are a suitable replacement for dried salmon or other dried protein sources that have been used in conjunction with an elimination trial. Therefore, Prescription Diet Hypoallergenic Treats are an ideal choice for patients diagnosed with a food allergy or inflammatory skin condition. Plus, the treats are low in calories—approximately 2 kcal per treat for cats and approximately 17 kcal per treat for dogs—and they have a great taste that dogs and cats love.

Kara M. Burns, MS, MEd, LVT Veterinary Technician Specialist Hill's Pet Nutrition

Kara Burns, MS, Med, LVT

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