How to Tell If Your Pet Has a Food Allergy

Food allergies in pets can be one of the hardest conditions to diagnose and treat. But you've got to spot it before you can treat it!
How to Tell If Your Pet Has a Food Allergy

Last update: 09 December, 2020

Diagnosing food allergies in pets can be really complex for vets. In fact, if you suspect that your pet has a food allergy, the vet will likely have to really put their brain to work to get to the bottom of the issue.

But why are they so difficult to detect? What symptoms do they cause? In this article, we’ll tell you everything you need to know about this immune process.

Types of allergies

So that you can better understand the diagnostic process, we’re going to start by dividing all allergies into three different types. They are:

  • Food allergies. This is when the allergen that causes an allergic reaction is found in food.
  • Environmental allergies. This is when the allergen is found in the environment.
  • Contact allergies. This is the easiest to diagnose. This is when the allergy is caused by contact with a specific object, like a collar or a food bowl.
  • Flea or tick allergies. As the name suggests, this is when a bite from a parasite triggers an allergic reaction.

These different categories might seem a little obvious, but you’ll see shortly why it’s important to be aware of them, particularly since it’s possible to suffer from more than one of them at the same time!

Foods that often cause an allergic reaction

Not all foods have the same potential to give your pet an allergic reaction. Whilst it’s true that technically pretty much any substance could contain a potential allergen, certain foods tend to be more guilty than others.

When it comes to meat, beef and chicken are the most likely to cause an allergic reaction. And when it comes to cereals, we’re normally looking at corn and wheat.

Types of food arranged in heart-shaped bowls.

How do I know if my pet has a food allergy?

There’s no easy answer to this question. Remember the previous list of allergies? Well, unfortunately, apart from contact allergies (which tend to cause a more localized reaction), all the others cause very similar symptoms.

Furthermore, to make things more complicated, allergies can develop at any time and at any age. Many pet owners ignore the possibility of a food allergy because their pet has always eaten the same food their entire lives.

Sadly, always eating the same food is no guarantee that your pet won’t develop an allergy from one day to the next. As surprising as it may seem, these spontaneous allergies aren’t just limited to pets; they can occur in people too!

The situation is the same with environmental allergies since they can also develop unexpectedly. For all these reasons, if your pet suddenly starts scratching a lot, it won’t be as easy as we might like to identify the cause.

Diagnostic approach

To identify an allergy, firstly, you’ll need to look at some clinical signs which tend to be quite non-specific. The most common ones are:

  • Itching and scratching
  • Red skin
  • Skin rashes
  • Conjunctivitis
  • Vomiting and diarrhea (sometimes)
  • Autoinduced alopecia (particularly in cats)

These symptoms may lead your vet to suspect an allergy, but in order to identify the cause, they’ll need to continue investigating and use more complex methods.

Currently, there are some diagnostic tests on the market which analyze the levels of immunoglobulin in the blood. These are present in the blood and are a way of measuring the presence of an allergen. Although they have a lot of potential, these methods are currently not as reliable as we might like, particularly with cats.

Therefore, the best diagnostic tool will be the old-fashioned process of elimination.

Process of elimination

This method of diagnosis consists of removing the main suspects from your pet’s diet. For example, if your pet has been eating pet food based on chicken or rice for many months, then you’ll need to find something else to eliminate this as the cause of the problem.

There is also the option of making your own pet food at home or even following a specially formulated hypoallergenic diet. The latter can have very positive results but tends to be much more expensive.

Once ready, it’s time to feed your pet a new diet exclusively for at least two months. It’s important to reiterate that they must only eat this new diet. If you also feed your pet treats, this could interfere with your results.

It’s a good idea to maintain this new diet for a reasonable period of time so that you can be sure to observe the results. If your pet responds positively and their symptoms improve, then it’s time to reintroduce your pet’s previous pet food to see if it causes an allergic reaction. If so, then you’ve found the culprit!

A dog looking sad next to a bowl of pet food because they have a food allergy.

We hope that this article has been interesting for you and that you can now understand how complex it is to successfully diagnose a food allergy in pets. But the first step, as with any condition, is detecting it as early as possible!

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