It turns out that dogs and cats have mast cells that release histamine and other highly reactive compounds just like humans EXCEPT that humans have more mast cells in their respiratory system and cats and dogs have more in their SKIN.
So that if dogs are over sensitive to fleas, pollen, dust mites, or certain food types they are likely to have skin inflammation, itchy paws, and overactive secretions of the anal glands, ears, and over the lower back.
For cats, allergies most often start as little scabs and areas of skin inflammation around the face and neck and then progress over the back
This page is about how we can manage skin allergies with special diets.
Here are some basic concepts that should clear up all the confusion surrounding hypo-allergenic diets*
* It's hard to generalize; each pet with allergies seems to be somewhat unique; you may have to try several hypo-allergenic diets before you achieve success. There are hard to measure factors like "stress" and "anxiety" in addition to actual allergic compounds involved in this disease. There's probably a genetic component too. The point here is that you can't just go to a web site or pet store for the one special diet that will make your pet comfortable.
* The most common types of skin allergies that we see every day in veterinary practices across the country are:
a - allergies to plant pollens, dander, dust mites and other allergens floating around in the air at ground level
b - allergies to fleas, ants, mites, and other insects
c - allergies to certain grasses and plants, saw dust, damp cement, wool carpets, and other "contact" allergens
d - allergies to certain food proteins. That's the subject of this page.
But take note: allergic pets don't tend to have either allergy a, b, c, or d : They tend to have some COMBINATION of a, b, c or d. For example, your dog might be allergic to wheat and soy, so finding a diet and treats without wheat and soy may make your dog a lot more comfortable.
BUT your dog might also be super sensitive to fleas and also react each Fall to rag-weed pollen.
Managing allergic pets is a multi-front battle and finding the right diet is often only a part of that battle.
If you have an allergic pet, there's about a 20% chance that THE RIGHT diet could make your pet "cured" and about another 20% chance that THE RIGHT diet will at least greatly improve the problem.
That means that about 2 out of 5 allergic pets are helped by going to the trouble of trying some special diets. It's well worth the trouble.
But it also means that for 3 our of 5 allergic pets, changing diets WON'T make a huge difference.
* There are many different BRANDS of pet foods, but most of them contain the same proteins even though they are different in color, taste, and texture. So just switching brands of pet food is NOT a good food allergy trial.
Pet food QUALITY or PRICE might be important for other reasons, but your pet can be just as allergic to the high quality beef in the expensive diet as it is to the animal by-product meal in the cheap diet. So switching to a more expensive diet is NOT a good food allergy trial.
It takes irritated skin 2-8 weeks to stop itching and heal once it becomes sensitized and inflamed from food allergies. So you need to be patient when doing food trials. Most people notice an improvement in their pet's skin after about 3-4 weeks if the diet is successful, but sometimes it pays off to try a little longer.
If your pet has excessive shedding, skin infections, skin odor, frequent ear infections, frequent anal gland problems, and is itchy, itchy, itchy, and miserable: your vet will recommend a food trial to help determine whether or not your pet has food allergies. It's well worth the effort and more accurate (when done right) and much less expensive than other testing options.
Here's what we're trying to accomplish when we do food trials:
1. Getting you, the owner, to stop giving any table scraps, raw hide chews, dental treats, pet treats, or anything else that MIGHT contain proteins that your pet is allergic to.
2. Choosing a diet made from "exotic" protein(s) that your pet is very UNLIKELY to be allergic to and sticking with it for 3-6 weeks.
3. Choosing a diet without a lot of artificial preservatives, coloring agents, artificial flavors and so forth that might cause allergies.
There are quite a few prescription hypo-allergenic diets available ... you may have to try several before achieving success... They are made from exotic protein sources not found in regular pet foods, and they are made without additives that might cause allergies.
These special diets will cost you about $20-40 more than your pet's regular monthly diet, but think of this as a very inexpensive lab test. If they make your pet much better, you don't have to continue feeding the expensive prescription diet (although a lot of people do)... we can then start adding different ingredients such as soy, beef, wheat etc to see what foods are causing the problem and then find a less expensive diet without those ingredients.
Canine Diets I recommend as a trial or test to see if your pet has food allergies:
Royal Canin Rabbit & Potato or Duck & Potato:
The number one veterinary recommended adverse food reaction diet in the world. Limited Ingredients: Each diet is formulated with a unique protein source and a single carbohydrate source (potato).
High digestibility to ensure optimal nutrition absorption.
Enriched with long-chain omega-3 fatty acids from fish oils to help reduce inflammation in the skin and digestive tract.
Available in a low calorie formula too.
Purina HA Canine Diet: Purina Veterinary Diet HA:
This is a very high tech vegetarian diet where the proteins molecules have been broken up into small molecular weight amino acids that don't trigger the immune system. (almost all allergies are associated with large sized protein molecules)
Hills z/d ULTRA Allergen-Free Canine Diet:
Prescription Diet® z/d® ULTRA Allergen-Free ULTRA Allergen-Free Canine contains no intact proteins to virtually eliminate the potential for an allergic reaction.
Hills d/d Potato & Salmon or Potato and Duck Diet:Includes enhanced levels of Omega-3 fatty acids and antioxidants, which have been shown to be useful for pets with a variety of inflammatory skin conditions that are often associated with excessive itching, scratching and licking.
If your dog responds really well to any of the above diets and stops itching, flaking, and shedding, you can continue feeding those diets ... Or ... you can do "challenge testing" where you introduce beef, dairy, soy, wheat, and corn and so forth one at a time for a week or so each to see what ingredients your pet is sensitive too... OR ... you could try any of the following less expensive, non prescription diets designed for pets with skin problems that may very well work:
Eukanuba's "Naturally Wild" diets which include
New Zealand Venison & Potato, Wild Salmon & Rice, or Turkey & Multigrain: These are super premium foods that are excellent for general health as well as for many allergic dogs.
Other Brands of "hypo allergenic" skin diets containing Lamb & Rice, or Fish & Potato: There a numerous regular dog food companies now offering hypo-allergenic diets that may or may not work.
Try the test diets listed above first, though, because they almost always work IF your pet has major food allergies.
Hills and Royal Canin also make hypoallergenic diets for cats. Cats seem to more prone to getting gastro-intestinal symptoms when they have food allergies.