Chronic Inflammation and Allergies in Dogs

I’m not a veterinarian, and this isn’t veterinary advice. Always check with your vet before starting any new medication or supplement, especially if your dog has an existing health condition. What I’m sharing here reflects my experience, along with evidence-based recommendations where available. I am a human nurse, and while I fully recognize the importance of licensed veterinarians in pet care, I also want to help empower breeders and owners to support their animals’ health with accessible and/or holistic options.

Chronic inflammation—manifesting in conditions like atopic dermatitis, paw licking, scratching, recurrent ear infections, and gastrointestinal concerns—is a common problem reported in companion dogs. These conditions - like most things- are influenced by both genetic and environmental components. Because there is definitely a genetic component, it is critical to avoid breeding dogs who are severely or chronically affected.

However, allergies are not inherited in a simple Mendelian way. These are complex polygenic conditions, meaning multiple genes are involved. Environmental factors also play a role. Like all breeding decisions, one must consider the entire dog, and make an effort to maximize the chances of healthy puppies.

Here are some things to think about whether you are a breeder or the owner of an itchy dog.

The role of bacteria in helping bodies - both human and canine- function properly is an exciting area of new research. Connections are being discovered between the bacteria in our intestines and everything from depression to IBS, to asthma. A healthy gut plays a critical role in immune regulation, and differences in the composition of gut bacteria in dogs have been linked to the risk of atopic dermatitis, which is a common, progressive form of skin inflammation that often worsens as a dog ages and is common in many breeds, including two of my favorites- labs and goldens.

Breeders play an important role in supporting the developing gut microbiome of puppies. There is growing evidence that a dams gut bacteria influences her puppies in utero, and that the method of birth ( vaginal vs c-section) matters.

A review dedicated to gut microbiota dynamics in puppies confirms that major shifts in microbial composition occur before, during, and shortly after weaning, with the most rapid changes within the first few weeks. Although microbial communities continue to evolve up to 1 year of age, the foundation of stable adult-like microbiome is laid early.

Breeders can help by ensuring that puppies are delivered naturally (without surgery) whenever possible, that they receive colostrum from their mothers in the first critical hours after birth, that they are not unnecessarily exposed to antibiotics which destroy healthy bacteria, and that they are introduced to foods during weaning that will support a healthy gut biome.

Here are some ways I suggest supporting gut health in a dog of any age:

• Feed a varied diet that includes fresh foods. Allergies to foods are easy to blame for itching but often not the real culprit. In many cases, we don’t really know if dogs are allergic to chicken (or some other ingredient), or the additives and highly processed components in dry kibble.

  • Try rotating quality kibbles to avoid developing sensitivities to one particular formula

  • Replace part of each meal or all of one meal a day with real food. The best things are lightly cooked meats, fish, non-starchy vegetables and low sugar fruits like berries

• Add small amounts of cultured foods like plain whole milk yogurt or raw unfiltered apple cider vinegar to meals

• The use of probiotics in dogs to improve allergies needs more research, but there are promising recent results. A good human or dog probiotic capsule or powder once a day is a great addition.

Omega-3 polyunsaturated fatty acids—primarily EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid)—have been shown to reduce inflammatory responses in dogs with allergic skin disease. Most kibbles do not provide an adequate amount of these important fats and they are not part of standard requirements for AAFCO (Association of American Feed Control Officials), the primary regulator of dog food in the US.

Studies support the use of omega-3 supplementation in dogs with atopic dermatitis and other inflammatory conditions. In particular, EPA has been associated with reduced pruritus, improved coat quality, and decreased medication reliance in affected dogs.

Dosing should be based on the combined EPA+DHA content per kilogram of body weight. Most veterinary sources recommend a range of 50–100 mg/kg of combined EPA and DHA daily, though higher doses may be used under veterinary supervision.

When choosing a product, look for:

• Triglyceride-form fish oil, which has higher bioavailability than ethyl ester forms.

• Third-party testing for contaminants such as heavy metals or oxidation.

• Minimal additives, flavorings, or carrier oils.

Fish oil can be given as liquid or capsules, with meals to improve absorption. In dogs with chronic inflammatory symptoms—including allergies, arthritis, or autoimmune conditions omega-3 supplementation is widely recommended. It is also a good choice for overall health and prevention of allergies in all dogs, especially breeding dogs.

Sardines in water with no salt added are a great way to get extra Omega 3’s into your dogs diet- and most dogs LOVE them. My dogs get these about 3x weekly.

The “hygiene hypothesis” suggests that a western way of life, including the extended use of anti-infective drugs, a high standard of hygiene and the resulting reduced exposure to microorganisms, could be one of the possible explanations for the increasing prevalence of allergic diseases in humans and animals.

Several factors in both early rearing environments and adult homes have been linked to reduced allergies in dogs including exposure to sunlight, time walking in the woods or on a beach, and being raised on a dirt floor. https://pmc.ncbi.nlm.nih.gov/articles/PMC10657834/

More research is needed before we can draw definitive conclusions. However, it is reasonable to assume that a lifestyle in which outdoor exercise and exposure to lots of different environmental bacteria, particularly early in life, are likely to work against the development of allergies.

Most dogs thrive when they have time outdoors to do normal canine things like digging, swimming, running and sniffing all over to look for yucky stuff and critters. If your dog is indoors all the time they may be missing out on some things needed to maintain their immune system and prevent allergies.

Things listed here are available over the counter for either canine and human use and are generally safe. Always be careful not to accidentally use products with multiple ingredients or human products on dogs without careful evaluation of the whole ingredient list for toxicity in dogs.

PEA

Palmitoylethanolamide (PEA) is a naturally occurring fatty acid amide that plays a role in modulating inflammation and pain. In dogs, PEA has been studied for its potential to reduce chronic itching, skin inflammation, and other allergic symptoms by downregulating mast cell activation and supporting immune homeostasis. It acts on the endocannabinoid system. PEA is available as an oral supplement and has shown good safety in veterinary use.

Gallo, S., et al. (2020). Palmitoylethanolamide in veterinary medicine: Current state and future perspectives. Veterinary Sciences, 7(1),

Quercetin

Quercetin is a plant-based flavonoid widely found in fruits, vegetables, seeds, and grains. It exhibits powerful anti-inflammatory, antioxidant, and antihistamine-like properties. One of the easiest and most natural ways to introduce quercetin into your dog’s diet is through food.

Many fruits and vegetables contain quercetin and this is the easiest and safest way to provide it to your dog. Apples (especially the skin), blueberries, and other bright berries are great sources. Parsley is another good source.

Supplements are also an option. Quercetin is generally considered safe for dogs when given at appropriate dosages, though some may experience mild digestive upset; it should be used cautiously in dogs with kidney disease or in pregnant/lactating animals, and vets should be consulted before starting supplementation.

Antihistamines

Antihistamines like Benadryl (diphenhydramine), Zyrtec (cetirizine), and Claritin (loratadine) are commonly used in dogs to manage allergic symptoms such as itching, sneezing, and hives. These medications work by blocking histamine receptors to reduce the allergic response. While they are not effective for every dog, they are generally safe when used at appropriate doses under veterinary guidance. Diphenhydramine can cause sedation, while cetirizine and loratadine are typically less sedating.

These medications are widely available, inexpensive, and definitely worth a try especially for short term use before resorting to powerful drugs that impact immunity in other ways like steroids and other veterinary medications. Consult your veterinarian for dosing recommendations.

Always consult your veterinarian before starting any medication. The above options are commonly recommended by vets but should be used responsibly and with medical oversight.

Hypochlorous Acid

Hypochlorous acid is a weak acid naturally produced by white blood cells. In topical form, it has broad antimicrobial and anti-inflammatory effects, making it useful for soothing itchy or irritated skin, cleaning wounds, and preventing secondary infections. It is non-toxic, safe if licked, and well-tolerated even around eyes and ears. It is available in several formulations and I have been amazed at how quickly it clears up minor skin irritations. I highly recommend trying this for ears or itchy paws.

Apple Cider Vinegar (Diluted 1:1 with water)

Though its effects in clinical trials for canine atopic dermatitis are limited, vinegar’s acidic pH helps inhibit fungal and bacterial growth, particularly Malassezia yeast. It can be used for minor ear infections or as a preventative flush. Use with extreme caution in severe infections because it is NOT SAFE if the eardrum is perforated or if the inflammation is severe it can cause pain. The best choice is a raw unfiltered form due to its potential to encourage healthy bacterial balance.

Clotrimazole

Clotrimazole is an antifungal medication commonly used in dogs to treat yeast and fungal infections of the skin and ears. It is available in creams, ointments and ear solutions. Care should taken to avoid contact with the eyes and to prevent ingestion. Clotrimazole is often combined with other ingredients (e.g., steroids or antibiotics) in products used for treating ear infections and localized fungal dermatitis. It is available over the counter for human use.

Hydrocortisone

Hydrocortisone is a mild topical corticosteroid commonly used to reduce inflammation, itching, and redness associated with allergic dermatitis, insect bites, hot spots, and other localized skin irritations. Hydrocortisone is safe for short-term use on small areas of intact skin. It should not be applied to deep wounds, eyes, or large surface areas over extended periods, as excessive use can thin the skin or suppress adrenal function. It is available over the counter for human use.

Allergy and chronic inflammation in dogs are driven by multiple interacting factors—genetics, diet, microbiome development, and environmental exposures. While perfect prevention is not realistic, breeding practices that focus on maternal health, nutritional diversity, and early gut biome support, together with owner-level management strategies can build resilience. Owners should be empowered to use diet and lifestyle interventions along with safe, evidence based supplementation and commonly available, accessible treatments as the first line of defense against symptoms.

Be well.