Mary Allen
A food allergy in dogs is a very annoying matter. Due to the severe itching, recurring diarrhoea and skin inflammation, the quality of life of the four-legged friend is severely impaired. About 15 per cent of all dogs suffer from a food allergy, many young animals already suffer from food intolerance. All information on this topic can be found in this article.
What is a Dog Food Allergy?
In the case of a feed allergy, an excessive reaction of the immune system is triggered by contact with various ingredients in the feed. Food allergy occurs mostly in young dogs, but can also occur in older dogs. Most often, the allergic reaction is associated with skin inflammation and severe itching.
Even if a feed is tolerated without any problems in the first few months, a dog can develop a feed allergy after a year.
Differences Between Food Allergy and Intolerance
Feed allergies and feed intolerances have been increasing in recent years. The food allergy in dogs is one of the third most frequently diagnosed allergies. Even if the terms feed allergy and feed intolerance are used as synonyms in everyday language, they are two different processes.
The immune system is always involved in food allergies in dogs
In the case of a food allergy, the dog’s body responds to a weak stimulus with a strong immune response. Stimuli can, for example, be different proteins (chicken, beef). The dog’s defence system treats the food as an invading pathogen. It forms antibodies and messenger substances that cause inflammation. The immune system responds to any further contact with a strong allergic reaction. Even the smallest amount of the allergen is enough to cause severe symptoms.
Food intolerance causes similar symptoms
Similar signs of illness appear in the case of feed intolerance. The dog suffers from diarrhoea, flatulence, vomiting and itching. However, the symptoms appear as soon as they come into contact with the food. There is no sensitization of the immune system. The reaction to the component of the dog food that triggers the intolerance depends on the amount contained in the dog food. Small amounts do not elicit a reaction.
Symptoms of a Food Allergy in Dogs
Food allergies in dogs always cause serious digestive problems. The dog suffers from flatulence, vomiting and diarrhoea. Because of the diarrhoea, the dog defecates up to three times a day. The stool is liquid and sometimes covered with a layer of mucus. Often the dogs also have pain in the gastrointestinal area. At the same time, red skin changes, which are associated with severe itching, form in the area of the face, external auditory canal, paws and abdomen.
The dog loses a lot of fluid due to diarrhoea. It dries out and the skin’s elasticity is reduced. The dog rubs against objects, slides on the floor and constantly gnaws its paws. With inflammation of the external auditory canal, the head is constantly shaken. Bacteria and fungi settle in the skin injured by scratching, which further increases the inflammation.
Causes and Triggers of Food Allergies in Dogs
Most food allergies in dogs are caused by protein in dog food.
Proteins that often trigger food allergies are:
- beef
- poultry meat
- soy
- Milk protein in cheese or yoghurt
- eggs
Grains that cause feed allergy:
- wheat
- Spelt
Rice and potatoes rarely trigger immune system reactions.
Allergens in ready-made dog food:
- Glycoproteins: Large molecules made up of protein and carbohydrates
- antioxidants
- Haptens: small proteins
Diagnosis and Treatment
A blood test can only detect an increased level of eosinophils (parts of the white blood cells) and an increased level of immunoglobulin E. Exact differentiation of the substances that cause the allergic reaction is not possible.
In order for the culprit to be identified, an elimination diet of horse meat, other exotic meats, insects, and a carbohydrate source must be followed. After the elimination diet, a provocation test is carried out. The dog receives an additional food component that could trigger the allergy. The diagnosis can therefore take a little longer. If you are unsure, you should always contact your veterinarian.
How is a dog food allergy treated?
The first level of treatment is the elimination diet. In the first eight weeks, the allergens already present in the body are eliminated. The intestinal tract calms down and the skin heals.
Special care shampoos promote the healing of the dog’s inflamed skin. The skin barrier is rebuilt with essential fatty acids in the feed or as a spot-on. If the dog continues to scratch itself frequently, it must be prevented from scratching with a funnel or a body. Cortisone is not a permanent solution as it only suppresses the immune system. The cause of food allergy in dogs is not eliminated by cortisone.
The most effective treatment is to avoid further contact with the allergen. Unfortunately, this is only possible to a limited extent. Dogs with a food allergy are often also allergic to flea saliva, dust mites and pollen.
Feed Diet
A feed diet to treat the allergy only contains proteins in which the protein molecules have been modified. The size of the individual protein molecules is greatly reduced by hydrolysis (cleavage of the molecules by a reaction with water). The molecules contained in the feed are now no longer able to trigger an allergic reaction.
Special feed diets are mainly used in dogs, which respond to many different types of protein with an excessive immune system reaction. The hypoallergenic dog food only contains a single source of protein and one source of carbohydrates.
Which Dog Food is Suitable for a Food Allergy?
If the dog has a food allergy, different foods can be fed once the allergen has been identified. This includes ready-made feed with exotic sources of protein, such as insects, horses or kangaroo, special diet feed from the vet or home-cooked feed.
The Elimination Diet
An elimination diet is the only way to identify the triggering allergen in the food. The dog is not on a diet, the amount of food is not reduced. However, he is given dog food that contains only one source of protein and one source of carbohydrate.
The following sources of protein are suitable for the elimination diet:
- horse
- kangaroo
- insects
In the past, fish, ostrich meat and rabbit meat were also used as nutrition during an elimination diet. In recent years, however, feed allergies to these types of meat have already occurred. Sweet potatoes, Jerusalem artichoke or millet are well suited as carbohydrate sources. Rice is not so good. Cross-reactions with poultry meat are likely to occur in ostrich meat. Buffalo meat is also not suitable for an elimination diet. Although it is not found in conventional dog food, it causes a cross-reaction with beef.
For eight weeks, the dog is fed a diet consisting exclusively of one type of meat and one type of carbohydrate. If the dog has a food allergy, the allergic reactions will disappear over time.
Now the provocation test can take place. In addition to the food, the dog receives another source of protein, for example, poultry meat. If the symptoms reappear, the allergen has been identified. If no allergic symptoms are visible after a few days, the search must be continued. The dog gets the next source of protein with the food.
Which feed can be cooked by yourself?
Of course, the elimination diet does not necessarily have to be fed ready-made food. But what can you cook and feed yourself? If the dog is used to being fed, an elimination diet should not be carried out with ready-made food. The home-cooked feed must be easily digestible and tasty. It should contain all the necessary nutrients so that there is no shortage of vitamins, minerals, and trace elements.
Once the allergen has been identified, care must be taken to ensure that it is no longer included in the dog’s diet. Even traces of the allergen can immediately cause an allergic reaction again. Some vegetables are known to cause cross allergies to meat. These include tomatoes, celery, parsley, basil, and bell peppers. Fruits such as apples, pears, and peaches can also trigger cross-allergies.
Common mistakes in feed diets
The time required for the elimination of allergens is often underestimated. Even if there are no longer any symptoms after three weeks, it is not yet possible to start feeding another protein source. The earliest time to do this is the seventh week of the elimination diet. However, it is better to wait eight weeks.
When it comes to the exclusion diet, the main thing is the consequence of the dog owner. The allergens can be found not only in normal dog food but also in snacks. If a normal snack or treat is fed in between, the dog’s allergy will quickly flare up again.
If feed supplements are added to the feed, care must be taken to ensure that they are not contaminated with a protein. Salmon oil, for example, must only consist of oils. There must also be no traces of protein.