Food incompatibility in dogs

Normal dog food is digested by healthy dogs without any problems. In contrast, dogs with a food allergy often have a reaction after eating a particular food that they cannot tolerate: diarrhoea, vomiting, flatulence, a distended abdomen or skin inflammation and irritation as well as flaky skin. Hair loss, ear and anal gland infections, unpleasant odour from the ears, loss of appetite and apathy can be further consequences.

It is important to note that these can only be indications. The symptoms should be discussed with your vet, as they could also be caused by other diseases.

In addition to a food allergy, an environmental allergy (pollen, contact allergies to the dog’s harness, for example), a flea saliva allergy or also parasites (fleas, mites), skin fungi, infections as well as behavioural problems (e.g. licking paws due to boredom) can also be the cause of itching and skin changes. Diarrhoea can also have many causes: gastrointestinal infections, stress (travelling, moving house, also positive stress), medication or deworming, parasite infestation, organ damage, etc.

Food allergies are relatively common in dogs. However, it is difficult to reliably detect a true feed allergy. The search for the cause is carried out exclusively through a strict exclusion diet, or elimination diet. Blood tests are often offered, but their significance is very questionable, and they do not detect any incompatibilities.

An exclusion diet is started with food ingredients that the dog has never had before. This means both a new type of meat and a new carbohydrate source. Once you have decided which food to give your dog, it must be fed for at least 8 weeks.

The indispensable basis of this diet is the consistent adherence to this strict eating plan. You and people around you must not feed any additional food at all during this time. This includes treats, special treats (such as pig ears, ox pizzle or bovine scalp) and especially treats from the table. This is because anything that the dog has in its mouth during this time can possibly trigger a reaction in the skin or digestive tract – and thus falsify the result. As snacks for in between, you can take the selected dog food (and subtract this amount from the daily ration). During walks, make sure that your four-legged friend does not help himself to anything. If in doubt, always walk your dog on a leash for this period. Only if the diet is carried out consistently can it give the desired result and provide information about the food allergy or food incompatibility and lead to a reduction in symptoms. These will not decrease immediately, but from about the second or third week onwards, or even disappear altogether once the right food has been found for your dog. On average, you need 3 to 4 attempts until this goal is reached.

When implementing such a diet, it is also important to take a close look at the label of the new food in advance. This is because information such as ‘meat and animal by-products (min. 4% xy)’ does not clearly indicate what other types of meat are involved. Therefore, ask the manufacturer more precisely or opt for dog food with an open declaration. You can find more on this topic in the article ‘Declaration of dog food’.

If your four-legged friend is on medication, discuss the ingredients with your vet with regard to the exclusion diet. The same applies to additional food and supplements if you cannot generally omit them. Some medicines or even dewormers given in the form of chewable tablets often contain meat meal or other animal ingredients to improve acceptance.

Once you have found the right food and your dog is symptom-free, it is advised to follow a so-called provocation diet, where a counter-reaction (a ‘provocation’) is induced. To do this, you need to feed your dog previous food components again step by step and wait to see if symptoms reappear. A reaction can occur anywhere from a few hours to several days after ingestion. In this case, take a step back and go back to the original exclusion diet until the symptoms have disappeared.

It is advisable to keep records over the entire period.