As responsible pet owners, we want to provide our dogs and cats with everything they need to enjoy a comfortable and happy life. Therefore, when they’re experiencing health problems, it can be a real source of stress. One potential cause for poorly pets is food allergies. Just like humans, our pets can experience adverse reactions to foods, which can cause some unpleasant signs. In this article, we’ll help you identify if your pet could be having an adverse reaction to their food, and how you might be able to help.
What are food allergies?
Dietary allergies occur when a pet’s immune system is inappropriately activated in response to the presence of harmless foods. It’s nearly always a protein within the food that the immune system incorrectly identifies as a threat and responds as if the body is under attack.
This can only happen when the immune system has been exposed to the protein at least once before and has learned to recognise it as a potential invader. That means that food allergies take time to develop, so can’t be ruled out just because your pet hasn’t had a diet change recently.
What are the signs of a food allergy?
Food allergies can cause a diverse range of signs in dogs and cats, but are usually suspected due to gastrointestinal or dermatological signs, particularly if both occur together. These signs include:
- Itching (especially if it isn’t seasonal)
- Foot chewing
- Recurrent ear and skin infections
- Poor coat quality
- Itchy anal area or face
- Loose stools
- Vomiting
- Gas
- Weight loss
It’s vital that you work with your pet’s vet to identify the cause of his or her illness. None of these signs are unique to food allergies, and there are other causes that may need to be ruled out, some of which could be serious.
How are food allergies diagnosed by the vet?
Unfortunately, there are no laboratory tests that can be performed to identify food allergies in dogs and cats. This includes blood, hair and saliva samples, which are not reliable when it comes to identifying food allergies. They will likely ask you to perform what’s known as an elimination diet trial.
They may also want to do a range of other tests to rule out other conditions that cause similar signs.
Elimination diet trials
The only way to determine whether a food allergy or intolerance is causing your pet’s problems, is to perform an elimination diet trial. This involves feeding a diet that is unlikely to contain the proteins your pet is allergic to. If it’s a food allergy, the signs should resolve, and the vet may then recommend re-introducing the original food to confirm that the pet’s signs return, and that the improvement wasn’t just a coincidence.
Special foods need to be used for elimination diet trials, so you should follow your vet’s recommendations very carefully. Often, the food recommended will contain hydrolysed proteins, such as Purina Pro Plan Veterinary Diets HA Hypoallergenic. In hydrolysed protein diets, the proteins have been broken down (hydrolysed) into smaller pieces, so that the immune system no longer recognises them as a threat. They are very different to other “hypoallergic” diets that are available, so you should ensure that you buy the specific food suggested by your vet.
An alternative is to use a diet containing novel proteins – those are proteins that your pet has never been exposed to. Remember that the immune system needs to have seen a protein before to recognise it (incorrectly) as an invader. This is a valid option but requires an extensive and accurate dietary history of everything your pet has ever eaten, to ensure that the protein is truly novel. This, coupled with other challenges such as cross reactivity between different types of protein means that hydrolysed proteins may be a more reliable choice.
It's important that you follow your vet’s instructions carefully during the trial, especially:
- Use the specific food recommended
- Feed it for the length of time advised
- It must be fed exclusively. That means no other foods or treats, unnecessary medications, supplements, toothpastes, bits of food dropped on the floor, or licking dirty plates. Because we don’t know what’s causing the allergy, assume that they are allergic to everything other than the special food. It's also important to check with your vet before stopping any medications.
Performing an elimination diet trial in a busy household can be tough, but there’s no better option. Successfully identifying a dietary allergy or intolerance in your pet is a reward that’s well worth the inconvenience!
My vet has diagnosed a food allergy, what next?
If the diet used for the elimination trial is complete and balanced for long term use where appropriate, such as Pro Plan Veterinary Diets HA Hypoallergenic, it can be continued indefinitely following advice from your vet.
If you want to find what the problem protein is, it is possible to add individual protein sources (e.g. chicken or beef), to your pet’s food to see if they react. It isn’t necessary to add anything to your pet’s complete diet, so don’t feel that you need to take that risk, if you don’t want to. However, this trial-and-error approach is the only way that the problem food can be specifically identified.
Purina Pro Plan Veterinary Diets HA Hypoallergenic diets for dogs and cats are complete dietetic pet foods suitable for puppies from 14 weeks old and adult dogs and cats, for the reduction of ingredient and nutrient intolerances with hydrolysed protein and selected carbohydrate sources.
In addition to containing hydrolysed protein, HA uses purified carbohydrates to help avoid allergic responses. It’s a highly digestible diet containing a blend of ingredients including omega-3 fatty acids, to support skin and gut health.
All indications for PURINA® Veterinary Diets mentioned are for the dietary support of the dog (or cat) with the listed condition and do not preclude appropriate medical management. The veterinary diets should be used under veterinary supervision.
