Many dogs in various parts of the country suffer from allergies. Allergies can be mild or severe, seasonal or non-seasonal. Allergies are often categorized into 3 main types, flea allergies, environmental allergies, and food allergies.
Signs of Dog Allergies

One of the most common signs that your dog has allergies is itching. Dogs scratch the ears, sides, or other parts of the body when they are itchy. Itching can also be seen as shaking the head, chewing at the paws, or rubbing against furniture or carpet. Some common places dogs itch are their paws, the belly or groin areas, and the ears.
Other signs of allergies could include:
- hair loss
- red skin
- rashes
- ear infections
- scooting the rear on the ground
- sneezing.
Flea Allergies
Flea allergies cause a condition known as flea allergy dermatitis, which is the most common skin condition found in dogs. A flea allergy is caused by a reaction to the flea’s saliva.
Saliva comes in contact with the dog when a flea bites. An allergic dog will react to the saliva and become itchy. Your dog is essentially having an allergic reaction to the flea saliva. Fleas are also a nuisance!

A dog with flea allergy dermatitis will become so itchy, they damage the protective barrier of the skin.
Dogs with Allergy Dermatitis can exhibit the following:
- scabs
- sores
- red skin
- skin infections from itching so much
It is common for a dog with flea allergy dermatitis to be found without fleas. This is because when a dog licks or chews at where the flea bites, they often ingest the flea or cause the flea to jump off and you don’t see it.
For more information on how to tell if your dog has fleas check our our article How to tell if Your Dog has Fleas.
What to do for Flea Allergies
- Flea prevention – The good news is that flea allergies are nearly 100% preventable. You must simply keep your dog on regular monthly flea prevention. Flea prevention can be a monthly oral chewable or tablet, or it can come as a topical application. It is best to visit with your veterinarian about what type of flea prevention is the best for your dog.

- Clean and treat the inside environment – You will of course want to make sure your house is flea-free if your dog has had fleas. This requires thorough vacuuming, cleaning, and pest control.
- Treat the outside environment – If fleas are a bad problem in your area, it may even be beneficial to treat your yard for fleas to help keep the numbers down.
- Give your dog a bath – If you see fleas on your dog, or if you notice they are extremely itchy, you can give your dog a bath to help get rid of the fleas and flea dirt. If there is a significant number of fleas or flea dirt, use plain Dawn dish soap as a shampoo. Make sure to limit the use of Dawn as it can aggressively dry out the skin. If there is a milder number of fleas, you can simply use a hypoallergenic or aloe and oatmeal shampoo to bathe your dog.
- Treat the infection – If your dog has a secondary skin infection because of flea allergies, make sure to bring your dog to see your veterinarian to get topical and/or oral medications to not only prevent the fleas, but to get rid of existing fleas, stop the itching, soothe the skin, and treat the infection. How to get Rid of Fleas on my Dog gives great detail on how to get rid of your dogs flea infection.
If you are looking for some great flea treatment collars we have some suggestions here. If you prefer a more natural approach try looking at some Home Remedies for Flea Treatment.
Environmental Allergies

A common allergy for dogs is an environmental allergy. This is an allergy to something in the environment and the condition is often called atopic dermatitis. What happens is that pollens, dust mites, or other harmless substances in the environment cause itching and inflammation when the pet is allergic to them. Yeast and bacteria can then invade the skin or ears to cause a secondary skin infection, adding to your dog’s itchiness.
It is often hard to narrow down exactly what your dog is allergic to without specific allergy testing. Ask your veterinarian if they can perform this testing or if it requires a referral to your local veterinary dermatologist.
What to do for Environmental Allergies
- Start by trying to narrow down what your dog might be allergic to. Are they itchier when they have been in the grass? If so, wipe down their paws with unscented baby wipes or a damp washcloth when they come in from being outside.
- Flea prevention – As discussed above, make sure your dog is on a regular flea prevention to ensure the itching isn’t related to fleas or a flea allergy.
- Fish oil – Fish oils have omega-3 fatty acids that can be anti-inflammatory and help keep the skin and hair coat healthy. Make sure to use a product meant for dogs or ask your veterinarian about dosing a human fish oil if you have a large dog.
- Bathe your dog – Regular bathing is important to help avoid allergens and ridding allergens already on your dog’s skin. Unless your veterinarian recommends a specific shampoo, use a gentle, unscented shampoo such as an aloe or oatmeal shampoo.
- Over the counter antihistamines – Antihistamines such as Benadryl or Zyrtec can be used for mild allergies. While they don’t treat the allergy itself, they help decrease symptoms such as itching and licking. Ask your veterinarian about the appropriate dose for your dog.
- Prescription medications and treatments – If the above suggestions don’t relieve your dog’s itchiness, a trip to the veterinarian may be required for something stronger to stop the itch. There are various prescription medications and even a shot that can help stop the itch. If there is a secondary skin infection, your veterinarian will prescribe topical and/or oral medications to treat this infection.
- Allergy testing and immunotherapy – Don’t forget to ask your veterinarian about allergy testing. By testing, you can find what exactly your dog is allergic to. This gives you the information to avoid allergens or to start immunotherapy. Immunotherapy is a targeted allergy treatment to desensitize your dog to the specific allergens.
Dog Food Allergies
If your dog has food allergies, you might notice they tend to itch and have hair loss around their mouth, eyes, ears, belly, and paws.

You might suspect a food allergy if your dog’s itching is not seasonal, still itching despite allergy medications, or has gastrointestinal signs such as vomiting, diarrhea, or gas. There are no specific tests for food allergies but if your veterinarian suspects a food allergy, they might recommend a diet trial.
Food allergies can develop even if your dog has been eating the same food for years. It takes time for food allergies to become a problem.
A common misconception about food allergies is that it is an allergy to grain in the diet. In fact, most food allergies are due to an allergy to the proteins in the food. This would be something like chicken, fish, beef, pork, or other main protein ingredients.
What to do for Food Allergies
Here are some steps to take to help you treat your dogs food allergies
Diet trial
A diet trial is the best way to find out if your dog is allergic to their food. You will need to start by making a list of the protein ingredients in everything your dog has eaten. This includes treats, kibble, canned food, and table scraps (if your dog gets any). This can be very difficult especially if you don’t know your dog’s full history. Do the best you can. For example, let’s say your dog has only ever had chicken and beef in their food and treats.
Select a Dog Food
Next, find a dog food that doesn’t have any of these protein sources. So, if your dog has only had chicken and beef, try a fish or lamb-based diet.
Feed the novel (new) protein diet for 8-10 weeks. You must be very strict about this, don’t give any other treats or table scraps and make sure all members of the family are on board.
Watch Your Dogs Reaction
Watch closely for changes in itching habits. If your dog gets better on the new food then you can test this by feeding the original food to see if the itching comes back, or simply keep your dog on the new food.
If your dog doesn’t get better, or gets worse, try a different protein source.
In many cases, a dog has had most of the common protein sources and you must find an exotic protein source. This is getting harder and harder as the variety of ingredients in dog food expands. An example would be the Royal Canin Selected Protein line – they offer more exotic protein choices.
In other cases, you might want to consider a hydrolyzed protein diet. These diets take the proteins and break them down during the manufacturing process to make them less reactive. These diets usually require a prescription from your veterinarian.
Aviod Home Cooled or Raw Diets
Avoid home-cooked or raw diets – Unless you are working closely with your veterinarian or a veterinary nutritionist, avoid making your dog’s food at home. When you feed home-cooked or raw diets, many important nutrients are forgotten, and this can lead to other health issues. In addition, if you don’t store and prepare the food properly, you can make yourself or your dog very sick.
Don’t forget the regular, monthly flea prevention.
Treat the infection – If your dog has a secondary skin infection because of food allergies, make sure to see your veterinarian to get the appropriate treatment.