Dog Allergies: All You Need To Know From Symptoms to Treatment
September 20, 2023 | 3 min read
Updated September 20, 2023
By Dr. Jacqueline Dobranski, DVM
Primrose Moss, VetMB MRCVS
Dogs with allergies suffer many signs, such as itching and ear infections. Keep reading to learn all about causes, symptoms, and how to treat dog allergies.
Can dogs have allergies?
Allergies are common in dogs across the United States and beyond. The three most common types of allergies in dogs are environmental allergy (atopy), food allergy, and flea allergy. Look no further for the most complete guide to allergies in dogs.
- Environmental allergy triggers in dogs include pollen, mold, and dust mites.
- Environmental, food, flea and contact allergies mainly affect the skin.
- Diagnosis is based on clinical signs and excluding other potential causes.
- Some breeds are more likely to develop allergies.
- You can help by limiting exposure to allergens.
- Supplements and medications can greatly relieve symptoms.
Causes of dog allergies
Canine atopic dermatitis (atopy), commonly known as seasonal or environmental allergy, is a common inherited skin disorder. Seasonal allergies to tree (ash, cedar, oak), grass, and weed (ragweed) pollen typically flare in spring and fall.
Some dogs with atopy are allergic to dust mites. These microscopic organisms settle in mattresses, upholstered furniture, carpeting, drapery, stuffed animals and pillows. Dogs with allergy to dust mites usually show year-round symptoms. House dust, containing dead skin cells and mold spores, can also trigger allergies.
Mold and mildew are another frequent trigger. Mold spores exist both indoors and outside. They thrive in moist areas, and can collect in bathrooms, kitchens, basements, garages, barns, and improperly stored dog food. Piles of dead leaves, logs, and compost can facilitate mold growth. Mold spores may also cause year-round allergy symptoms.
Atopic dogs have a weak skin barrier to these allergens, allowing them to pass through and trigger the immune system to overreact. Immune cells in skin release histamine and other inflammatory molecules, causing severe inflammation and itching.
Some dogs are allergic to specific proteins in the food or treats they eat. This could be beef, chicken, eggs, dairy, wheat gluten, soy, or other ingredients. Dogs with food allergies have similar skin problems to those with atopy. It doesn’t make a difference if the diet is homemade or a commercial dog food. If the food contains the triggering ingredient, the dog will experience symptoms.
A flea allergic dog may not appear to have fleas, because it only takes one flea to trigger intense itching. The allergy is actually to the flea’s saliva.
A highly effective flea treatment and preventative can be used to diagnose or rule out flea allergy. These treatments may be a combination of topical and oral products. Further, the home and dog bedding should be deep-cleaned to remove flea saliva and eggs from the environment.
Contact allergies are less common, but worth a mention here. Some dogs develop a rash around the muzzle when they eat or drink out of a plastic dish. This is easily remedied by switching to ceramic or stainless steel bowls. A severe rash may require medication to clear up quickly. Other sparsely-haired areas such as the belly and groin are most susceptible to contact allergies from lying down on a triggering substance. Symptoms usually occur within hours to a few days.
Acute allergic reactions
Acute, or immediate-type allergic reactions create severe symptoms upon exposure to the offending allergen. Examples include vaccine reactions, bee stings, insect bites, and spider bites. Reactions include facial swelling, hives (bumps), trouble breathing, and collapsing. In severe cases the dog may go into shock and require emergency veterinary treatment.
Signs of allergies
What are the signs of allergies in dogs? Dogs with environmental or food allergies may show any of these signs; for other types of allergy, symptoms may be more specific. Environmental allergies often cause itching as pollen counts rise, but this can be year-round depending on the allergen.
Behavioral symptoms include:
- Licking and chewing paws
- Rubbing the face and ears on carpet or furniture
- Scratching and chewing the body frequently
- Scooting the rear end along the carpet
- Scratching and digging at ears
- Sneezing and coughing
- Vomiting and loose stool from swallowing hair and dirt when licking/chewing, or as a result of a food allergy
In addition, allergies can alter the appearance, feel and smell of a dog's skin and cause other symptoms.
Physical signs include:
- Interdigital skin (between the toes) becomes red, swollen, and oozy
- Hot spots, or localized skin infections
- Skin around eyes, mouth, armpits, thigh folds, chest, belly, and paws appears red and irritated
- Bumpy rash, often indicating a secondary bacterial or yeast infection.
- Over time, skin thickens and darkens in color
- Ear infections
- Odor due to increased oil production and/or skin, ear, and anal gland infections
- Red, watery eyes and clear nasal discharge
Flea allergy often causes a more intense skin reaction at the base of the tail, while contact allergies are usually more localized to locations like the belly and less haired areas of skin. Acute allergic reactions can cause a range of symptoms (see above), which can affect any area - hives (raised bumps) are usually seen on the face, body, back and upper legs but can occur anywhere.
What can I give my dog for allergies?
Dogs with allergic skin disease have been shown to have a damaged, weakened skin barrier. A strong skin barrier helps to keep out allergens and infections – so what can we do to support dogs’ skin barriers? Effective management of allergic skin disease often combines home care, including bathing and supplementation, with medication if needed.
Essential Fatty Acid (EFA) supplements contain Omega 3 and Omega 6, which have been shown to help support the skin barrier and reduce allergy symptoms in affected dogs. These supplements typically contain fish oils but can also contain plant oils like flaxseed. Many different forms are available including capsules, oils to add to your dog’s food and even specifically formulated diets.
Probiotic supplements may also help. The link between the gut and skin health is incredibly complex but well established – and a study has shown that probiotics containing Lactobacillus and Enterococcus can reduce itching in dogs with atopy. These often come as palatable tablets and soft chews so many dogs will happily take them.
Vitamin E levels can also be low in dogs with atopy and supplementation may help with skin health.
While some owners notice rapid improvements, it’s important to remember that looking after allergic skin is a marathon, not a sprint – supplements work best when given long-term and you may notice gradual improvement with time.
Medications also play an important role in the management of allergic skin disease, both for short-term treatment of flare-ups and long-term control. Steroids have been the mainstay of treatment for many years – they’re powerful, effective and work quickly. However, they also have a range of side effects, especially if used long-term. New medications in the form of regular injections or tablets are now available for management of chronic skin disease and these are often very effective, with far fewer side effects. Topical medications and other products can also help; oatmeal-based shampoos and conditioning products, for example, can play a significant role in soothing inflamed allergic skin.
Finally, low doses of specific allergens can be given by injection to ‘desensitize’ dogs with environmental allergies. Unlike other medications, this ‘immunotherapy’ is based on progressively reducing the immune overreaction that causes allergies. It can improve dogs’ symptoms over time, allowing other medications to be reduced or even stopped.
How to reduce symptoms of dog allergies
- Walk your dog before sunrise or in late afternoon or early evening when pollen counts are lowest.
- Rinse or wipe paws and body with a damp cloth upon entering your home.
- Outfit your dog with booties to minimize allergen contact outdoors.
- Walk and exercise your dog in paved areas such as sports courts.
- Vacuum your home (floors, furniture and drapes) frequently with a HEPA filter vacuum.
- Use HEPA air purifiers and keep windows closed.
- Wash all bedding and soft toys weekly in hot water.
- Use dust mite covers on beds and pillows.
- Generally manage sources of mold and mildew such as damp areas and stored pet foods.
- Bathe your dog with an oatmeal-based dog shampoo to maintain the skin barrier and remove allergens.
What causes allergies to develop?
Any pure breed and mixed-breed dog can develop allergies, but certain breeds are genetically predisposed. These include Golden Retrievers, Labrador Retrievers, German Shepherd dogs, Boxers, French Bulldogs, and West Highland White Terriers, to name a few. Allergies in dogs tend to run in families since this is a genetic condition. When choosing a puppy, it's appropriate to ask about allergies in the parents. Atopy typically starts between the ages of six months and three years. If your ten-year-old dog just started itching, it is less likely to be due to allergies. However, food allergies can develop later in life - and mild atopy can be missed when dogs are young - so it’s important to discuss this with your vet.
Final words on dogs with allergies
Allergic dogs can require a significant investment of time, money, and patience from their owners. By taking steps to reduce allergen exposure, starting supplements and medications before allergy season begins, and by treating secondary infections right away, many of the worst symptoms of dog allergies can be managed or avoided. Dogs do not grow out of allergies. On the contrary, they tend to get worse over time.
Discover PetLab Co.'s full dog health range, featuring joint care, probiotics including America's top-selling Probiotic Chew*, dental products, and supplements to help support with itching and allergies.
If your young dog shows the behavioral and skin symptoms described above, mainly intense itching and inflamed skin, he/she may have allergies. If this coincides with high pollen counts, seasonal allergies are even more likely.
By giving long-term Essential Fatty Acid, Vitamin E and probiotic supplements, you can see improvement in allergy symptoms at home. You can also help by avoiding allergens and removing them from your dog. The list above gives tips on how to do this outside and at home. Oatmeal-based baths can help remove allergens and soothe inflamed skin.
If your dog is itching (scratching, licking, and chewing themselves) frequently or has abnormal-looking skin despite home treatment, it’s time to see your veterinarian. The goals of a vet visit are: to relieve itch, treat infection, diagnose allergy or other problems, and create a long-term plan.
In addition to supplements, baths, and medications, a veterinary dermatologist can perform an intradermal skin test to determine the exact species of pollen, mold, and dust mites that trigger your dog’s allergies. Allergy shots made with these allergens are given over many months to desensitize your dog. This works well enough in many dogs to reduce the need for expensive medications every year.
Dr. Jacqueline Dobranski, DVM
Dr. Jackie Dobranski has enjoyed twenty-five years of caring for pets in the District of Columbia, Virginia, and Maryland. Through volunteering with shelter animals and writing veterinary articles, she enjoys helping pet owners find care and information they need. She loves spending time with her family, rescue dog, and rabbits.