Animals

Food Allergy in Dogs - Symptoms and Treatment

Dogs with food intolerance suffer from symptoms similar to gastroenteritis, such as diarrhea and vomiting.

  • Author: By CAROLINA PINEDO
  • Publication date: May 16, 2013

Diarrhea, vomiting, gas and discomfort are the usual signs of a dog suffering from intolerance to certain foods. This article gives answer to five questions about canine food intolerance, between them, what is it, what are its symptoms, what to do when it appears and how to differentiate it from a food allergy in dogs.

Lactose and protein in food are components that cause digestive intolerance in dogs. The diagnosis of this disease is complicated, because you have to determine the specific foods to which the dog has intolerance.

Food allergy is a different pathology to intolerance, although it has similar treatments. Therefore, diagnosis is key to determine exactly what disease it is.

Here are five common questions about food intolerances in dogs.

1. What is a dog food intolerance?

Food intolerance in dogs is "a process located in the intestinal tract, while food allergy is triggered by a reaction of the immune system," explains veterinarian Maria Victoria Acha.

An allergy is a pathology that can have more serious consequences for the health of the dog, including death.

Food intolerance, on the other hand, can be compared to a heavy digestive process, with symptoms such as gas, discomfort in the abdominal area and diarrhea, due to an incorrect assimilation of nutrients provided by food. It is associated with the following cases:

A toxic reaction to bacteria or additives that contain food.

A reaction of the dog's organism to certain drugs.

A metabolic deficiency of can, as in the case of lactose, which makes it impossible for milk to assimilate.

2. How to differentiate intolerance from a food allergy?

Food intolerance in dogs implies a problem to assimilate some meals

Veterinarians differentiate an intolerance of a food allergy in the dog through the symptoms. Some of them are common in both pathologies, such as diarrhea, but in the case of allergies to food, specific signs appear that do not occur in intolerances. Some of the most repeated are respiratory disorders in the dog and skin, hives or itching. A food allergy implies, against intolerance, a reaction of the immune system of can.

However, when the dog does not tolerate a food, reacts regularly with digestive problems, such as vomiting, gas and diarrhea.

3. How is the dog's food intolerance diagnosed?

Finding out the foods to which the dog has intolerance is essential in the diagnosis of food intolerances. Veterinarians use several techniques for this.

"One of them is a blood test to detect immunoglobulins or certain antibodies, "explains Ignacio Arija, veterinarian and animal nutrition expert at the Complutense University of Madrid. However, this test through the dog's blood is not entirely reliable and must be complemented with other tests, nuances

In other studies the reaction of the dog's skin (dermoreaction) to contact with certain substances. These analyzes, however, are complex and sometimes impractical.

Therefore, the most common is to use the food elimination test, which is to offer the dog a hypoallergenic diet for eight weeks. This diagnostic technique is similar to that used with a dog suffering from food allergy.

To eliminate foods that produce intolerance in dogs are used hypoallergenic feed, which are manufactured with hydrolyzed proteins or divided into smaller amounts than usual, to avoid adverse reactions in the animal's digestive system. The homemade diet For dogs with food intolerance is another option.

Once the two months of diet have elapsed, the rest of the food is introduced gradually, and one by one, the rest of the food to elaborate a road map with the foods that cause the pathology and carry out the diagnosis.

4. How is food intolerance of can treated?

Food intolerance in dogs is treated with a hypoallergenic diet

Dogs suffering from intolerance require a lifelong hypoallergenic diet, based on hydrolyzed feed, to avoid situations of food intolerance.

Veterinarians usually recommend a homemade diet prepared under his supervision. The food intolerance of the dog can remit with time, so the veterinarian can repeat the tests to determine if the dog begins to admit them without problems.

5. Can you prevent dog food intolerance?

A dog is born with the predisposition to suffer food intolerances. In fact, there are certain breeds, such as the French bull dog and the boxer, that suffer more frequently.

However, it is unknown if a dog suffers from food intolerance until the first symptoms appear and the disease is diagnosed.

In any case, for all mammalian puppies, the breastmilk It is essential for the transmission of antibodies, as they strengthen the immune system and prevent adverse reactions to food.

The high-end feed or excellent quality They facilitate the digestibility or optimal use of nutrients and avoid the remains in the intestine of the dog, which cause gas and heavy digestions.

How to detect food allergy in dogs?

Although a priori it may seem that the symptoms of food allergy in dogs are going to be fundamentally digestive, the truth is that the most characteristic sign is the itching and consequent scratching to relieve it. Food allergy can appear in dogs of all ages and without the seasonal pattern that will appear in allergies triggered, for example, by pollen.

The foods most related to allergic reactions are meats, milk, eggs, fish, cereals or soy. The allergy is a hypersensitivity reaction before a substance, in this case proteins, which, in principle, should not be dangerous for the organism. If the immune system considers it, it is when the allergy occurs. The dog must be exposed to the allergen one or more times to trigger the reaction. Therefore, it is more common in dogs that have been on the same diet for some time.

Symptoms of food allergy in dogs

How does food allergy manifest in dogs? As we have said, food allergy dermatitis in dogs is going to be the main symptom. This disorder causes intense redness and itching. We will be able to appreciate, also, small packages of red and wounds due to scratching. It is very normal for this skin disorder to affect the lower area of ​​the body and ears, causing the otitis for food allergy in dogs. The feet and the back of the legs are usually affected.

Finally, food allergy diarrhea in dogs is rare. A rapid digestive transit may appear in the food intolerances. Therefore, if we suspect that our dog has an allergic disorder, it is important that the veterinarian confirms the diagnosis, since, in addition to being confused with intolerance, dermatological problems could also be due to other types of allergies or diseases.

Symptoms of intolerance to feed in dogs

As we have just seen, intolerance and allergy are two totally different conditions, so they also develop different symptoms. Thus, a dog with intolerance to feed will develop diarrhea and / or vomiting, accompanied by abdominal pain. Instead, a dog with a feed allergy will show the mentioned signs of dermatitis. Of course, in both cases the dog is not intolerant or allergic to all feed, but to one or more of its components.

Food allergy tests in dogs

To confirm a diagnosis of food allergy, the veterinarian will resort to a test of hypoallergenic diet. This consists of offering the animal what is known as a elimination diet, that is, with foods that you have never eaten before, regardless of the rest, which are eliminated. For sale we will find different feeds or wet food made with few ingredients of less usual consumption. They contain no artificial colors, preservatives or flavorings. There are also products formulated with hydrolyzed proteins. This means that proteins have broken into smaller fragments to which the body does not react. This way the allergy cannot be triggered. If the dog's symptoms improve with this change in their diet, the diagnosis of food allergy will be confirmed.

Of course, we can also carry out this elimination diet with natural foods. In fact, this way it is easier to find the exact food or foods that trigger the allergic reaction. Of course, we recommend using this diet under the advice of the veterinarian.

Finally, we can also request the realization of a allergy skin test to the main food allergens.

How to cure food allergy in dogs?

The first thing we should be clear about is that food allergy is not going to cure, but if we prevent the dog from eating the food to which he is allergic, he will lead a normal life. In this way, if what you want to know is how to remove your dog's allergy, you already have the answer. Therefore, the treatment involves giving that food to which the dog does not react. For this, it is essential that we prepare a detailed list of all the foods you have consumed throughout your life, since the objective is to provide you with a completely new menu.

The new diet Selected should be given for about 8-10 weeks. If we appreciate improvement, and always following the instructions of the veterinarian, we can add food one by one with the aim of locating the one that triggered the reaction. We will identify it because the dog will manifest the symptomatology again. If a diet works it will be maintained indefinitely.

Therefore, do not expect food allergy pills in dogs, since the treatment exclusively includes intervention in feeding. Instead, drugs could be prescribed if scratching has caused serious dermatological lesions. The goal would be to control itching, reduce inflammation or treat infections, if applicable. In the next section we will stop at antihistamines.

Antihistamine for dogs

Allergic reactions are caused by a release of histamine, so antihistamines, which are prescribed for treatment, may be included. when there is itching or dermatitis, in this case because of our dog's food allergy.

In the market there are several types of antihistamines for dogs that can be administered and that act differently in the body. It is the job of the veterinarian to choose the most appropriate and schedule the dose. In no case should we medicate the dog with drugs for human use. Antihistamines are used only when there are symptoms. Corticosteroids can also be used but, again, it will be the specialist who determines their use.

Homemade diet for dogs with food allergy

In food allergies it is possible to resort to home remedies, since the diet we can prepare at home, with fresh food chosen and controlled by ourselves and without any additive, it is an excellent choice for these animals. Of course, for the menu to be balanced it is essential that we prepare it with the help of a veterinarian with good knowledge of nutrition, since, otherwise, we could solve the allergy but cause deficiencies. As we have said, it must consist of ingredients that the dog has not previously consumed or that we have verified that they do not produce any allergic reaction in it.

To know how to start a homemade dog diet, do not miss this article: "BARF dog diet". This type of feeding usually works very well in dogs with food allergy, so it is an excellent option when it comes to home remedies for food allergy in dogs.

Food for dogs with food allergy

Now, if, for whatever reason, the dog does not follow a homemade diet, we have already commented that there is a variety of feed for dogs with food allergy, as well as other more natural foods made, too, to treat these types of conditions. In general, these products are made with foods that produce a lower percentage of allergies in dogs, found thanks to studies. Also, remember that they do not usually include artificial colors or flavors. For all this, we always recommend looking for those feeds or foods that are as natural as possible and that are made with natural ingredients and fit for human consumption.

And if the veterinarian has finally diagnosed your dog intolerance, and not allergy, do not miss this other article: "I think for dogs with food intolerance."

This article is purely informative, at ExpertAnimal.com we have no power to prescribe veterinary treatments or make any kind of diagnosis. We invite you to take your pet to the veterinarian in case he presents any type of condition or discomfort.

If you want to read more articles similar to Food Allergy in Dogs - Symptoms and Treatment, we recommend you go to our Other health problems section.

Warning signs

There are certain messages that dogs emit when they are affected by allergic reactions derived from the consumption of some foods. So you should pay attention to your body language and review it carefully.

These are some of the food allergy symptoms in dogs that occur more frequently.

Have inflamed skin

It looks flushed, swollen. You may also have a rash on your belly and legs. Another warning sign is that small bumps or pimples are appearing on the skin. These usually itch a lot, so it will scratch constantly causing more aggressions on your skin.

Is food allergy the same as intolerance?

There is a distinction that must be made between what is food allergy and what is food intolerance.

If you give your dog, for example, chicken and after a while he vomits and has diarrhea and you give him chicken again and the same thing happens, then this is that your dog has intolerance. If, on the other hand, you give him chicken and it feels good, without vomiting or diarrhea but his legs, chest and / or ears itch, this can be called food allergy.

Difference between a dog with food allergy or food intolerance: If the dog vomits what he has eaten or has diarrhea it may be intolerance. If the dog feels good about what he has eaten but has itchy legs, ears and / or chest it may be food allergy.


Food allergies show the characteristic symptoms of skin and itching problems associated with dog allergies.

Food intolerances can cause diarrhea or vomiting, and not create a typical allergic response.

Food intolerances in animals they are very similar to those of people who get diarrhea or stomach ache for eating spicy or fried foods, for example. Fortunately, both food intolerances and allergies can be eliminated with a diet free of offensive agents.

Several studies have shown that Some of the ingredients in the diet are more likely to cause food allergies than others. The most common causes of food allergies caused in dogs are the Dairy products, chicken, lamb, fish, chicken eggs, corn, wheat and soy. Therefore the most common cause is precisely the most common ingredients in dog food. This correlation is not a coincidence. While some proteins may be slightly more antigenic than others, many are similar in shape and the incidence of allergic reactions is probably associated with the amount administered.

What symptoms may appear in case of food allergy?

The main symptom is itchy or itchy skin that mainly affects the face, hooves, ears, front legs, armpits and the area around the anus. Symptoms may also include. Chronic or recurrent ear infections, hair loss and baldness in the fur, excessive scratching, hot spots and those skin infections that respond to the use of antibiotics, but that reappear after discontinuation of administration.

There is evidence that dogs with food allergies they can sometimes have a higher frequency of bowel movements. Several studies have shown that non-allergic dogs have about 1.5 bowel movements per day while in some dogs with food allergies they may have 3 or more per day.

It is difficult to distinguish an animal that suffers from food allergy from an animal that suffers from atopy or another type of allergy based simply on physical signals.

However, there are some signs that increase the suspicion that food allergy may be present. One of them, are ear problems recurring, as we mentioned above, in particular caused by fungal infections.

Another sign is the Moderate or severe skin problems, especially if the dog is young.

Redness and itching in the hooves and legs is a possible symptom of food allergy.


A third sign is if you suffer from allergies all year, or if the symptoms begin in the winter.

As well, if your skin itches frequently and does not respond to any treatment with any type of steroid It can be a sign of food allergy.

Due to the fact that many other problems can cause similar symptoms and that many times animals suffer more problems than just food allergies, it is very important that all other problems are properly identified and treated before undergoing allergy diagnosis. the food.

Atopy, flea bite allergies, hypersensitivity of intestinal parasites, sarcoptic mange, yeast or bacterial infections can cause symptoms similar to food allergies.

Food trials and elimination diets: A food trial involves feeding an animal with new sources of protein and carbohydrate food (that the dog has never eaten before) for at least 12 weeks.

A large variety of such diets have been in the market for a long time. The veterinarian can be a good reference in this aspect to give your dog a kind of quality diet.

You can also find specialized diets that contain proteins and carbohydrates that break down into molecular parts so small that it would no longer lead to an allergic response. These diets are called hydrolyzed protein diets. Homemade diets for these cases are often used, since the ingredients can be carefully controlled.

Regardless of the diet used, it should be the only thing the animal eats during the 12 weeks. This means that no flavored medications, no raw meat, no toys with food or flavorsAbsolutely nothing but special food and water.

If you want to give your dog some dog biscuits, prizes or snacks, it has to be based on the diet food you are giving him.

You must also have a control over the dog's access to other food or garbage, trying to record any incident related to this for veterinarian control.

Veterinarians usually recommend taking this type of special diet for 3 weeks, but new studies show that in dogs with food allergies that this diet has been applied, 26% responded from day 21 and the vast majority, without However, he responded within 12 weeks.

If the dog shows a marked reduction or elimination of symptoms, then the animal is re-administered original food. This is called "provocation test"and it is essential to confirm the diagnosis. If the symptoms return after returning to the original diet, the food allergy diagnosis is confirmed. If there has been no change in the symptoms, but there is still suspicion of an allergy to food, another type of new food can be included in your diet.

This is the best method to know if your dog has a food allergy and what are the causes of food allergy.

Can blood tests give us evidence of any food allergy?

About blood teststhere is no evidence that the analytics are accurate for the diagnosis of food allergies. There are dermatologist veterinarians who insist that there is nothing conclusive in these tests of any kind in the diagnosis of food allergies.

While specialized blood tests can be used to help diagnose atopy, satisfactory results are not obtained in the diagnosis of food allergies.

Redness of the legs

This symptom is characterized not only by redness per se, but by show signs of inflammation, areas without hair, and when touched, the temperature increase in the epidermis can be perceived. If your dog licks its paws a lot it is also a symptom of food allergy.

What treatment can be followed in case of food allergy?

The veterinarian is the one who must diagnose any food allergy in the dog and indicate the treatment based on the judgment of their food with the corresponding diet and the subsequent provocation test.


Obviously, it is the veterinarian who must give the appropriate treatment based on the previous trial of the food that the dog consumes and then the causes are eliminated from the diet.

A short-term relief may be by administering fatty acids, antihistamines and steroids, but eliminating harmful products from the dog's diet is the best solution.

If you choose to feed your dog with a homemade diet, then you can periodically test the pet with the introduction of new ingredients and determine what ingredients may be causing the food allergy. New foods are introduced to those already in their control diet and if new allergic symptoms are found, identify and remove the causative foods.

Homemade diets are essential that they are balanced, with the right amount of all their nutrients. Homemade diets for such long-term use should be developed by a veterinary nutritionist.

Keep in mind that some pets with food allergies may develop food allergies if they are administered for a long time or very often. If it is seen that different signs of food allergies return it is important that the veterinarian who supervises it is consulted.

You know, if your dog has an episode about food allergy or intolerance of a particular food, visit your veterinarian, he can help you.

Stomach and digestive tract signs

These are the immediate food allergy symptoms, a sudden intoxication, rather than being a reaction to a specific food that always has a reaction. Among them are:

  • Bad breath, different from the common product of salivary secretion.
  • Threw up.
  • Diarrhea.
  • Many flatulence.
  • Nausea, that is, arches.
  • Excess salivation.
  • He is drinking a lot of water.
  • He complains when he makes his needs> Why does my dog ​​have a food allergy, if I've always given him the same?

There are various factors that affect the fact that your dog has an adverse reaction to the food that you have always given him. On the one hand, smaller or very large-sized breeds tend to have a certain sensitivity to specific proteins or to carbohydrates and starches.

Part of the common diet or the contents of meals in croquettes, are precisely rice and chicken, two of the foods that contain starches and fats that affect dogs. This does not mean that all dogs have the same type of reaction, since not all organisms work in exactly the same way.

But how is a reaction possible if it is the same brand of food that you have always used? Well, as in all industrialized processes, it is possible that the trace of other foods has been cast, or that there is a new ingredient in recipes, especially when the brand launches an improved product. Surely your dog has a greater sensitivity to the change of food and therefore, has these symptoms.

How to help my dog ​​out of the allergenic crisis

Once this symptomatology is presented, it is vital to go to the vet for a detoxification treatment and evaluation. He will give you the guidelines to improve your dog's food process, however, also follow these guidelines that will be helpful in the process:

  • Do not drastically change your diet. Go eliminating part of the processed food and combine it with homemade recipes that include vegetables and lean meats.
  • Avoid giving your dog fatty foods, as well as carbohydrates or giving off high levels of starches, such as potatoes, corn, wheat, rice and pasta.
  • Always keep fresh water in your dog's cup.
  • Do not forget to give the antiallergic prescribed by the veterinarian.
  • Prevents the sun from midday and rather take the morning, so your skin will be less irritated.
  • Bathe it only with soaps specially designed for dogs in extra soft formula, to lessen the effects of the reaction on the skin.
  • Offer your dog more food with fish.
  • Do not give him excess food. Just like humans, dogs must maintain a weight according to their size.
  • See if he thinks you give your dog has coloring. Avoid those that contain it.

Maintaining the health of your dog is vital so that he can continue to accompany you for a long time, maintaining a physical and mental balance. Remember that when presenting any type of symptomatology described, you should go to your veterinarian as soon as possible to receive precise indications that make you improve.