Are you worried your dog might have allergies? Allergies can be complex and unfortunately, quite common. According to a NationWide insurance survey, allergic dermatitis was the most common reasons for pets’ vet visits. Dogs can experience many different types of allergies, such as environmental allergies, food allergies, and acute allergic response. With each allergen, the signs can differ - from itchiness to vomiting. Understanding what an allergy is and the associated signs, may help bring you one step closer to understanding what is affecting your pup.
What is an allergy?
A dog experiences allergies when their immune system over-reacts or is hypersensitive to a certain substance (allergen). Often times, allergens can be from insects, plants or grasses, or foods.
Allergens can be inhaled or absorbed through the skin, respiratory tract, or gastrointestinal tract. The immune system may see this allergen as an intruder. If this happens, it will tag the substance with antibodies. This tag will alert the immune system next time your dog is exposed to that same allergen (also known as an antigen). With the next exposure, the antibody and antigen react with mast cells, leading to the release of histamine and other substances. These substances cause the allergic response with redness, swelling, and itchiness.
Types of allergies
Flea or insect bite allergies
While many dogs will show only minor irritation from insect bites, some dogs’ immune systems may over-react to the bite or sting of insects. Flea allergy dermatitis is one example of an insect allergen in dogs. Some dogs are so sensitive to the saliva of fleas that they can cause excessive hair loss near their tail.
Environmental allergens, such as dust, pollen, grass, and mold, can cause an allergic reaction. Dogs with environmental allergens often show signs around 1 to 3 years of age.
Often, environmental allergens are seasonal, leading to itchiness during certain times of year. However, there are some environmental allergens, like molds and dust mites, that may stick around all year. Some dogs may start with seasonal allergies but progress to non-seasonal allergies, with signs all year round.
Dogs with environmental allergens may chew their paws or scratch their ears and are more prone to skin infections. These can also affect their muzzle, face, legs, underarms, and groin.
Dog with food allergies may develop a hypersensitivity to a particular ingredient in their food. This can be any ingredient, including protein, carbohydrate or even vegetables.
Dogs with food allergies may experience signs all year round or when they are fed the ingredient. Dogs may be itchy around their ears, feet, and their abdomen. Some dogs may even lick around their hind-end. With food allergies, your pup may experience chronic ear or skin infections.
Dogs with food sensitivities can also show digestive issues. You may notice vomiting, diarrhea or persistent loose stool, or gassiness. If they are unable to properly digest their food, due to the intolerance of specific ingredients, they may also lose weight.
Typically dogs with food allergies begin to show signs between 6 months and 3 years of age. However, dogs of any age may show signs if they are exposed to an ingredient that doesn’t sit well with them.
Acute allergic reactions
Acute allergic reactions, or anaphylaxis, can occur in dogs just as it does in people. Vaccines and bee stings are two examples of potential anaphylaxis reactions for dogs. With acute allergic reactions, a dog may experience itching, hives, facial swelling, excessive drooling, vomiting, and diarrhea. In more severe cases, the dog will have difficulty breathing. These reactions can be very severe for some dogs, and can be potentially fatal if left untreated. Luckily, these reactions are rare in dogs.
If your dog experiences the signs of an acute allergic reaction, no matter how severe, consult with your veterinarian.
Symptoms of Allergies
The symptoms of dog allergies vary depending on the cause, but some general signs to look out for include:
Red itchy skin
Dogs with allergies often scratch, lick, or chew at their skin excessively, which can lead to redness, swelling, and irritation. Their ears may also be affected, leading to itchy ears or chronic ear infections. Watch out for other signs of itchiness
Rash or hives
Allergic reactions can cause a rash or hives to appear on the skin, which may be accompanied by swelling and redness. With allergic reactions, you may see swelling of the face, ears, eyelids, or lips.
Sneezing and coughing
Dogs with allergies may experience respiratory symptoms such as sneezing and coughing. They may also show signs of congestion in their nose. However, if your dog is coughing, it’s important to get them checked by your veterinarian, as coughing can indicate other illnesses.
Allergies can cause a dog's eyes to become red, swollen, and watery. This can lead to excess eye discharge. If you notice any signs of discharge or redness, take a closer look. It’s easy to be fooled by their cuteness when they paw their eyes or rub then against you.
Vomiting and diarrhea
Allergic reactions can cause digestive symptoms such as vomiting and diarrhea. With acute allergic reactions, vomiting may occur very suddenly. With food intolerances, vomiting, diarrhea or persistent loose stool may occur more regularly after your pup consumes a certain protein source or ingredient. Paying attention to when your dog has digestive troubles may help you find the cause.
Note: Dogs can have severe anaphylactic reactions, just like people. Signs can include itching, hives, a swollen face or muzzle, excessive drooling, vomiting, and diarrhea. In more severe cases, dogs may have trouble breathing and show a blue color on their tongue and gums. If your dog is experiencing any of these issues, contact your veterinarian immediately.
If you suspect that your dog has allergies, it is important to speak with a veterinarian for proper diagnosis and treatment. To give your dog a voice between non-emergent vet visits, try the DIG Labs Health Check. The DIG Health Check app performs a FREE 10-second health check to analyze a photo of your dog’s stool, skin, and more. Click here to try.
- White, Stephen et al. Allergies in Dogs. https://www.merckvetmanual.com/dog-owners/skin-disorders-of-dogs/allergies-in-dogs. 4 Jan 2023.
- Weir, Malcolm. Allergies in Dogs. https://vcahospitals.com/know-your-pet/allergy-general-in-dogs. 4 Jan 2023.
- Veterinary Practice New. Dermatitis, gastropathy among top pet insurance claims. https://www.veterinarypracticenews.com/dermatitis-gastropathy-among-top-pet-insurance-claims/. 6 Jan 2023.