Common symptoms of food allergies in dogs and how to take care of them

Snapshot: Are you a dog owner? Are you noticing any allergic symptoms or changes in your pet’s behaviour? Just like humans, even dogs can suffer from food allergies and food intolerances. Since both these conditions manifest similar symptoms, dog owners find it difficult to understand the actual cause of the reaction. 

Food allergy is one of the most commonly found allergies that affect dogs. In case of a food allergy, the dog’s immune system reacts and forms antibodies to foreign substances. Food allergy reaction involves the production of antibodies. That’s why symptoms of food allergies manifest after prolonged exposure. Food allergies in pets can occur at any age. If you are a pet owner and willing to know more about food allergies, continue reading below. 

How is dog food allergy different from dog food intolerance? 

A food allergy is primarily caused due to a food protein that triggers an adverse reaction to the dog’s immune system. Due to the absorption of entire protein particles, the mast cells release her amines, excessive amounts of which can cause diarrhea or other allergic symptoms. 

In a dog food intolerance, there’s no involvement of the dog’s immune system. However, signs of dog food intolerance are somewhat similar to the ones of food allergies. That’s why it becomes difficult for dog owners and veterinarians to know whether the allergic reaction is due to food intolerance or food allergy.

What causes food allergies in dogs? 

Food allergies are different from food intolerance. Food intolerance is the result of poor digestion, such as lactose intolerance. People and dogs with lactose intolerance are either missing or have low levels of the milk digesting enzyme lactase.

Food allergy is caused when any kind of protein invades your dog’s immune system. The protein that upsets your dog’s immune system is present in the food that it takes every day. Proteins are an important constituent present in most dog foods. Besides meat, there are proteins present in vegetables and grains. Any of these foods can cause a food allergy in your pet. 

The gastrointestinal system comprising the stomach, mouth, and intestines protect your dog from potential allergens. The gastrointestinal parts constitute about 70% of the dog’s immune system. When your dog consumes food, the food first enters the stomach and gets digested. The larger food particles are broken down into smaller ones for better digestion. 

The enzymes and stomach acid work together for this purpose. The partially digested food then enters the small intestine where it is further digested until the proteins get fully disintegrated into their smallest parts, amino acids. Amino acids can be absorbed into the dog’s body with the help of special cells called enterocytes. 

Enterocytes serve in two ways. They welcome amino acids that they like while bouncing off the ones they don’t like. When an entire protein block passes through the intestine instead of being broken down into amino acids, enterocytes don’t allow the protein block to get absorbed. Thus the dog’s immune system reacts, showing symptoms of food allergies. 

How does the immune system work? 

IgA cells are a special type of immune cells that are present in the intestine. Some of these cells float freely inside the walls of the intestine while others stick to the walls of the intestine to prevent whole protein particles from getting absorbed into the bloodstream. Just like in volleyball, here too the protein particles are bounced back for more digestion. The better the digestion process in the stomach and intestine better would be the absorption. 

What happens when the immune system fails? 

If your dog is suffering from poor nutrition, the enterocyte cells might not function properly. In such cases, a damaged enterocyte can often allow the entire protein block to get absorbed in the cells. This disturbs the gastrointestinal defense system in the dog’s body and the body is forced to react consequently. Thus an allergic response is formed. 

Now, every time your dog consumes the same food, the response of its immunity system becomes greater. Continuing to eat the same allergic meal daily only worsens the condition. Soon, hypersensitivity is formed. Every time the dog eats the food, the mast cells release her timing. If the amount of histamine becomes too much, the dog might suffer from diarrhea or chronic skin infections within a few days. 

Which foods are likely to cause allergies in dogs? 

Below enlisted are some common foods that are likely to cause food allergies in dogs: 

  • Egg
  • Chicken
  • Dairy products
  • Beef
  • Wheat
  • Barley
  • Corn
  • Oats
  • Rice

Facts about dog food allergen you must know 

As a responsible dog owner, there are a few important things you must be mindful of. 

  • Starches are safer

Starches, also known as pure carbohydrates are a considerably low source of protein. This implies that dogs aren’t usually allergic to them. Though there are certain exceptions: potato starch is comparatively safer but whole potatoes, a source of protein can be allergic to dogs. The same is the case for higher protein sources like wheat and corn. But overall, allergies from grains are less common than meat allergies 

  • With fats, purity matters

Pure fats like fish oil are protein-free sources and are hence less likely to trigger an immune reaction in dogs. However, during processing, few traces of protein might sneak into oils and fats. Even these minor traces of proteins can cause severe issues. 

  • Look out for gelatin

If you feed supplemental oils to your dog, be careful as they sometimes come in gelatin capsules that can potentially trigger allergies in dogs. 

  • Peanut allergies are rare in dogs

If allergies are caused due to peanuts, though they are extremely unlikely, such allergies aren’t usually as severe as they occur in humans. If you are feeding peanuts to your dog, you have no reason to worry. 

  • No two foods are the same

If your dog is allergic to one food, it doesn’t necessarily mean it would be the same for other foods. Dogs allergic to chicken won’t necessarily be allergic to Turkey. 

  • Watch for additives

Preservatives, chemicals, flavorants, or colourants won’t trigger a food allergy but might cause an adverse reaction or intolerance symptoms. So be mindful about these. 

  • Food labels don’t always tell the whole story 

Sometimes, canned foods and other commercial dog foods get tested for proteins though the list doesn’t mention anything about that. 

What are the common symptoms found in dogs? 

The most common symptoms of food allergies in dogs have been mentioned below. 

  • Allergic dermatitis

It’sondition when your dog experiences excessive itchiness. Itchy skin is the most common type of symptom found in dogs. Skin itchiness can occur in any part of your pet’s body. Usually, the areas around the ears, rear end, paws, and stomach show signs of itchy skin. 

  • Skin issues

If your dog’s immune system has malfunctioned and absorbed an entire protein block, you might notice itchy bumps on your dog’s skin within 6 to 24 hours. If skin problems aren’t visible, you have to watch for them or feel them. 

Sometimes skin irritation takes longer to appear. 

If your dog is suffering from hives or itchy skin, there can be two side effects: 

Either your dog will bite, scratch, or lick the itchy areas which can consequently cause broken skin. If that portion remains untreated, there’s a possibility of catching an infection. So make sure things don’t get too far. 

Your dog can also experience excessive hair loss due to rigorous scratching.  

  • Stomach problems

Food allergies might show signs in the form of gastrointestinal issues like vomiting, gas, diarrhea. 

  • Swollen face 

If you notice swelling in your dog’s lips, ear flaps, or eyelids, probably it’s due to a food allergy. 

  • Chronic paw or ear infection 

Repeated infections in your dog’s paws or ears might also be indicative of food allergies. However, in most cases, this usually happens due to food sensitivity. 

If you notice your dog suffering from any of them, contact your veterinary doctor immediately and get a thorough check-up done. 

How is the condition diagnosed in dogs?

If your veterinarian doctor thinks the symptoms are indicative of a food allergy, he might recommend the below-mentioned tests:

  • Allergy testing

Just like it takes time to find out the reason for food allergies in humans, the same goes for dogs. Finding out what caused the allergy can be done in various ways. Usually, doctors follow the elimination diet procedure. 

  • Elimination diet

Your veterinarian doctor might prescribe a special diet for your dog during the trial to find out the cause of food allergy. 

Firstly, what you need to find out is whether the symptoms are indicative of a food allergy or food sensitivity. Food sensitivity is extremely different from food allergy. If it’s actually due to a food allergy, your vet would suggest a different diet that has a different protein and carbohydrate source than what you used to feed your dog. Usually, the best anti-allergic foods for dogs that veterinarians usually suggest are potatoes, kangaroos, and oatmeal. These foods prevent the immune system from continuing to respond in various ways.

  • Hypoallergenic diet 

Veterinarians might also recommend you to feed a hypoallergenic diet. A hypoallergenic diet consists of food made up of hydrolysed proteins. This means that protein particles in these foods are already broken down into smaller particles. These particles get further broken down when they pass through the stomach and intestines and hence are easily absorbed by the IGA cells. 

Rice foods and lamb are considered to be the best hypoallergenic foods available for dogs. Usually, most commercial dog foods are made up of corn or wheat, or chicken and dogs are habituated to having these common foods. That’s why opting to feed them rice or lamb is a good option as dogs are unlikely to have consumed such foods before. 

Though lamb and rice are considered to be hypoallergenic and rare food for dogs, some dogs are even allergic to lamb and rice as well. This is normal because an allergy can develop from any kind of diet that fails to be broken down into the smallest particles. If your dog is allergic to ride and lamb diet too, try feeding it other food items like sweet potato, oatmeal, fish, etc. 

While your dog is under a special diet, make sure it doesn’t consume any other kind of commercial food like sweets, rawhides, treats, cookies, or people food. Since it’s difficult to find out what exactly is causing the allergy, you shouldn’t feed it anything other than the diet and trigger its body’s allergic reaction. If you notice your dog not reacting to the special diet, you can slowly introduce other dog foods to its diet. Don’t feed varieties of items on the same day. This will help you figure out what or which food caused the problem. 

Don’t try to do this alone. Consult a professional veterinary doctor and take expert suggestions. That’s the only way to find the cause of the allergy and cure it in a nutritionally fulfilling way. 

How can you cure it?

The most common question among dog owners is whether there’s any preventive method they can adopt to stop food allergies from occurring. This remains one of the toughest questions in dog nutrition to date. While there’s no definite answer to the above question, veterinarians have suggested a few ways that would prevent dog’s immune systems to get triggered, thus helping them fight off numerous allergies. Some of the effective methods have been mentioned below: 

  • Promote a healthy mucosal barrier

You can do this by ensuring that your dog gets enough nutrition and health care. 

  • Watch out for gastroenteritis

If you don’t take care of your dog’s gastrointestinal system from an early age, your dog would grow up developing food allergies now and then. That is because your dog’s gastrointestinal system would get triggered even at minor incidents. Preventing gastroenteritis is easy theoretically- all you have to do is not allow your dog to feed on anything other than dog foods and treats.

 But practically, it’s difficult to be followed. Dogs eat lots of other things apart from proper dog meals. Some might not be harmful like bark, dirt, grass, wild berries while some can be a little harmful like horse dung or cow dung. Others like dead animals or rotten garbage can completely upset the dog’s stomach or digestion process causing food allergies. It’s very hard to monitor what’s going inside your dog’s mouth. 

If you are doubtful about your dog has consumed anything that might upset its tummy, it’s best to give it a low protein diet consisting of boiled potatoes and white rice until you are sure that the tummy has recovered. You may also consult a veterinarian doctor in this case. If your dog has been suffering from diarrhea for more than 72 hours, without any sign of recovery or getting better, it’s best to consult the doctor.

Dog owners are advised to not assume things and treat their pets themselves. Don’t give excess medications because diarrhea helps to get rid of bad things present in the intestines. If you are giving medicines to stop diarrhea, it would mean preventing the intestine from getting cleaned completely. If the unwanted things continue to remain inside the gut for long, it may cause serious illness.  

  • Promote effective protein digestion

Usually, dogs aren’t supposed to have difficulties while investing in proteins. If you are feeding it a homemade food or raw diet, you are advised to grind or blend the food( protein source) in a food processor for better digestion. There are a few commercial foods available where the protein is already ground. All you have to do is prepare the meal and feed your dog. 

  • Choose a dog food with exclusive protein sources

A diet consisting of a maximum of two protein sources would leave you with more diet options later on if your dog develops a food allergy. If you are feeding limited protein sources, it also helps you understand the cause of food allergy better. For instance, if you feed chicken, duck, turkey, salmon, and tuna regularly, you would have a tough time looking for a different protein source other than these five. This can be challenging for food owners.

You would also have a tough time trying to understand which exact protein source is the cause of food allergy out of the five. On the other hand, if you feed chicken as the staple source of protein, you can switch over to a different source that doesn’t contain chicken, in case it develops a food allergy. 

Preventing the occurrence of food allergies in dogs that have grown up with gastroenteritis might be next to impossible. Some breeds are especially noted for food allergies. As a result, specific dogs carry the tendency to develop food allergies genetically. In that case, it’s better to avoid breeding such dogs. If the food allergy isn’t too severe, it can be controlled or cured by changing the diet that they usually eat. 

When you take your dog to the vet, it may suggest a skin cream or medication help ease symptoms for the time being. The long-term plan for dealing with food allergies can be different. Though rare, a life-threatening allergic condition can occur. Your pet might even suffer from difficult breathing. If that happens, immediately call an emergency animal hospital and address the issue to expert veterinarians. 

For dogs suffering from food allergies, feeding a different, fresh diet, especially the one prescribed by a professional vet is an excellent choice. Often switching to a different diet has been found effective. Not only does that cure the allergy, but also improves the dog’s skin and coat. It even enhances the dog’s health, energy, and weight. So, if you notice food allergy symptoms in your pet, make sure to bring it to the vet’s notice immediately and get it cured as soon as possible. 


Hi, I'm a big dog lover. Goldendoodle and other similar poodle cross breeds have become my favorite. I've had two of them in my lifetime and thought to share my experience with the rest of the world.

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