Flea hypersensitivity and environmental/inhalant allergies
Because flea hypersensitivity and environmental/inhalant allergies far outnumber true food allergies in dogs, I address both along with the strict elimination diet. Also, if there is any history of yeast overgrowth, I always suggest eliminating all grains immediately, from diet and treats.
Flea hypersensitivity is an extremely common problem and is probably the most common allergy. The dog is allergic to certain proteins in flea saliva. Affected dogs can go crazy from one bite.
I feed a fresh raw diet, but I understand that this isn’t practical for everyone. However, there are good canned foods these days and even good kibbles, and many grain-free choices.
What is an elimination diet and why use it?
A strict elimination diet means a menu of foods the dog has never eaten; allergies develop over repeated exposure.
The elimination diet is the only way to definitely ID a canine food allergy, because the scratch (intradermal) test, the gold standard of allergy IDing, is appropriate for inhalant/environmental allergies, but not food allergies, on which they give too many false positives and negatives.
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If the dog has inflamed paws and other signs of atopy, I try very hard to avoid steroids (with their long-term dangers) and I start the following:
Supplement vitamin E when supplementing fish oil
I give a dog with atopic dermatitis a gram (1000 mg.) of fish oil a day per ten pounds of dog weight. (Some recommend a gram per ten or twenty pounds of dog weight.) I give the dog a (200 IU or 400 IU capsule of Vitamin E (preferably in the form of “mixed tocopherols”) based on his size.
Fish oil supplies long-chain Omega 3s. Dogs don’t have the ability that humans have to convert the ALA from flax or canola into the long-chain EFAs called DHA and EPA. Even in humans, this conversion is limited.
These Omega 3 EFAs are anti-inflammation agents.
Dogs use Vitamin E while processing oil supplements, and oil supplements should always be accompanied by E supplements. The E actually in the fish oil is insufficient. The Vitamin E is used by the system to prevent rancidity in the delicate unsaturated oil.
I suggest asking the vet for two-week trial prescriptions of antihistamines. According to a Tufts study, antihistamines work far better with fish oil than on their own. Dogs react very individually to antihistamines, which is why I am saying trials of different ones. Many dogs receive no benefit, but I believe it’s worth trying. My best successes have been with Chlorpheniramine and Hydroxyzine. Dramamine does not have a particularly good history, unfortunately.
Keep a journal
I’d keep a journal of wind and weather conditions (and seasonal changes in itchiness) when the dog is itchiest. This will provide info about the likelihood of pollen, grasses, etc., allergens.
Keep a close watch on his ears. Ear infections are painful, and MUCH easier to nip in the bud than clear up when there is debris or pus. They are a common secondary effect of allergies.
Keep pollen and grasses out of the dog’s bed by baby-wiping or rinsing his undercarriage and paws when he comes in from a lawn or other grassy area. It’s not that they grasses and pollen cause contact dermatitis, but that you don’t want to drag them into his bed and your carpet for him to be breathing constantly.
I will use the smallest dose of Pred for the shortest time possible when necessary to break an itch cycle and restore the quality of life.
And remember that the scratch tests are the gold standard of allergen IDing. They are followed by desensitizing injections based on the individual dog’s test results. Blood tests are less accurate.
All these suggestions are only my opinions, and I am not a vet.
Unfortunately, nutrition and allergies are two areas not usually well-covered in vet schools, which is why I started studying them a few years ago.