One of the most common complaints canine patients present to me with are skin problems, usually pruritus (itching).
Atopic dermatitis (AD) is an itchy skin disease caused by an allergic reaction to either an environmental or dietary allergen. This reaction presents as intense itching, rubbing, licking, and chewing at a patch or patches on a dog’s skin.
The itchy, raw skin reaction is the same whether the allergen is pollen, flea bite, or a food allergy, so some testing is required to determine the underlying cause of the reaction.
How does food impact dog’s itching?
Environmental allergies are reportedly more common than dietary ones, with adverse food reactions (AFRs) also causing similar clinical signs to an allergy without the immune system being involved.
This is why your veterinarian will recommend specific tests and/or elimination diets to confirm the exact cause of the AFR. One method often used is to feed a hydrolyzed elimination diet (ED) for a minimum of 6-8 weeks before re-introducing the previously fed diet or a specific ingredient within.
The goal of this is to ascertain if the clinical signs resolve and then recur when your pup’s diet is reintroduced. During the elimination diet period, it’s essential that your dog is only fed the special diet, and no treats are permitted.
Some studies have suggested that supplementing your pooch’s diet with polyunsaturated fatty acids (PUFAs) such as omegas 3 and 6 fatty acids can reduce itching and may even help reduce the amount of medications required to control clinical signs (Logas & Kunkle, 1994 and Watson et al., 2021).
Vitamin E and C supplementation may also help to reduce the severity of clinical signs in dogs with AD. A recent study also indicated that feeding a diet high in antioxidants, polyphenols, and the PUFAs eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) reduced the itchiness dog’s experienced due to food reactions.
Foods to Avoid
There are no specific foods to avoid in all pooches with itchy skin caused by food antigens. If your pup has been diagnosed with a sensitivity to a specific ingredient, then obviously, that should be avoided in their diet.
You’ll often see reports that the most common food allergens are beef or chicken, but that’s because they’re likely the most commonly used protein sources in commercial canine diets and not that our pooch dogs are inherently allergic to these proteins.
Another commonly reported “evil” ingredient is gluten, but the celiac disease has only been diagnosed in Irish Red Setters to date, so gluten doesn’t need to be avoided for the vast majority of our furry friends.
Common Ingredients used in Hypoallergenic Diets
There has been increasing popularity and availability of commercial hypoallergenic diets in recent years. A hypoallergenic diet is one that’s specially designed and formulated to minimize the risk of adverse reactions due to a dietary source.
These diets are often targeted at dogs with food sensitivities and have a few things in common. Some of these diets have extrapolated directly from human medicine with little evidence on their application in our canine companions’ lives. Some diets have eliminated ingredients that are common human allergens, such as soy and gluten. These are listed below:
Novel Protein Source
Many hypoallergenic diets contain a single protein source that isn’t commonly used in commercial diets from the dog store.
These include games such as venison and buffalo or even insect proteins. One concern with the advent of the popularity of these diets means that many more dogs are being exposed to these diets as a matter of routine which will reduce their suitability for those that develop food sensitivities or skin reactions due to environmental allergens.
Commonly seen in prescription diets hydrolyzed proteins have been completely hydrolyzed into their constituent “building blocks” of amino acids and peptides to a point where the body doesn’t recognize them as a specific protein source that could be an allergen.
What else can I do to relieve my dog’s itching?
Having an itchy pooch is incredibly distressing, so you’re constantly searching for any way to soothe their discomfort. While diet changes can be helpful, there are a few ancillary methods of easing your dog’s itchiness.
Colloidal Oatmeal Baths
Completely safe for your pooch (they’ll likely have a taste), bathing them in oatmeal can help soothe swelling and redness that contributes to itching.
Use aloe vera that is completely alcohol-free (to prevent drying out skin) to relieve redness and reduce heat to gently ease itchiness for a short period.
Veterinarians often prescribe medicated shampoos and ointments to help relieve itching while supporting the skin’s natural barrier against environmental allergens.
For severe cases or those that don’t respond to home remedies, your veterinarian may prescribe oral medications such as corticosteroids or anti-histamines.
There are newer medications with arguably less side-effects and improved efficacy available also, such as oclacitinib which aims to stop the inflammatory chemicals produced that cause pruritus.
What Does the Science Say?
Studies have shown that your dog’s diet can impact skin health and support their natural defenses against environmental allergens and irritants as well as food sensitivities that lead to skin reactions.
Some studies have even found that providing a modified diet such as an elimination or limited-ingredient diet can even reduce the amount of medication some pooches require to control their skin irritations (Watson et al., 2021). Novel protein diets may also be suitable, these are diets that contain a protein source that your dog is unlikely to have been previously exposed and thus shouldn’t have a sensitivity. Examples include buffalo, venison and even insect proteins (Böhm et al., 2018).
When to see a vet?
If your dog has a mild itch due to a sting, bite, or even a dietary indiscretion, you may not need to attend your local DVM clinic as the irritation may be manageable at home using home remedies such as aloe vera, a small amount of hydrocortisone cream (click here for our comprehensive article on the topic) or bathing in soothing shampoos (check out our review of soothing shampoos, here).
You should see your vet if the irritation persists or if there is any foul smell that could indicate an infection that needs anti-microbial therapy. Intense itching or broken skin may also need stronger medications, so if you have any concerns, contact your veterinarian in the first instance.
Food sensitivities in our canine companions are likely not as common as often thought. However, we now know that modifying a pooch’s diet can actually relieve some skin irritations even if diet wasn’t the inciting cause of the reaction. Nobody wants their dog on medication if it can be avoided, and that includes your veterinarian. This is partly why your DVM may recommend an elimination diet to determine if and what your dog is sensitive to with regard to food, and it’s imperative that the diet be strictly adhered to in order to ensure accurate results.
Offering your dog a single source or novel protein diet can help reduce itching and may even lessen the reliance on medication for pooches with skin conditions. Skin-supportive diets are also enriched with omega 3 and 6 fatty acids while supplemented with vitamins E, C, and B complex. Speak with your veterinarian for advice tailored to your best furiend’s needs.
Logas, D., Kunkle, G.A. (1994). Double-blinded crossover study with marine oil supplementation containing high-dose icosapentaenoic acid for the treatment of canine pruritic skin disease. Vet. Dermatol. 5: 99-104
Watson, A., Rostaher, A., Fischer, N.M. & Favrot, C. (2001). A novel therapeutic diet can significantly reduce the medication score and pruritus of dogs with atopic dermatitis dueing a nine-month controlled study. Vet. Dermatol.
Böhm, T.M.S.A., Klinger, C.J., Gedon, N., Udraite, L., Hiltenkamp, K. & Mueller, R.S. (2018). Effect of an insect protein-based diet on clinical signs of dogs with cutaneous adverse food reactions. Tierarztliche Praxis. Ausgabe K, Kleintiere/heimtiere 46(5):297-302