The Heska® Food Reaction Test FAQs

1. What is a Food Reaction Test?

A Food Reaction Test (FRT) is:

  • An indicator of the patient’s immune reactivity to food proteins
  • An assessment of the food the pet is currently receiving
  • A practical tool for the selection of alternative protein sources for an elimination diet

2. What about food allergy testing?

A food allergy is a medical condition in which exposure to a particular food component triggers a harmful immune response. The immune response occurs because the immune system reacts against proteins or protein fragments in the food. The proteins that trigger the immune reactions are called allergens.

There is no reliable food allergy test. There are several reasons for this; the etiology of the food allergy, the nature of adverse food reactions and food intolerances and other causes.

The clinical symptoms on all of them are similar involving hypersensitivity, dermatological condition, vomiting, diarrhoea, heavy digestion, etc.

A small proportion (5-15%) of allergic dogs show specific IgE against food components assessed using the Fc-epsilon receptor technology to detect IgE. This is why IgE testing alone is important, but of
limited value.

FRT takes another perspective. FRT is not a food allergy test, it detects immune reaction to individual food components. FRT allows the ranking of food components that are recommended to be excluded in a dietary change or elimination trial.

3. Is the Food Reaction Test actually reliable?

The Food Reaction Test is accurate for what it is designed for; the identification of immune reactions to food components. It is meant to identify the food components to which the body reacts as a starting point for a dietary change or elimination trial.

Due to the fact that there are no reliable tests for food allergy the common clinical practice is to perform an elimination trial. The key point is what proteins should then be used. Today the approach remains very subjective.
The process is long and challenging to perform correctly.

The components used for elimination are a matter of preference which may work in some cases and not in others. FRT can be of use to identify the food components which have more chances to provide better results. In addition, according to experts, the re-challenge to a successful elimination diet does not often confirm the elimination diet results.

4. What does the test measure?

FRT measures a combination of IgE and four IgG subtypes to foods. It will score the total reactivity levels for animal and carbohydrate proteins separately.

The food components with the lowest scores are the recommended components to be used.

5. FRT is an immune reaction assessing test, what does it mean? In which aspect is FRT new?

FRT is the first immune reaction assessing test available. FRT detects grouped immune reactions against food components. In patients presenting a digestive or gastrointestinal condition, FRT is used to determine if the food the pet is eating is suitable. If not, which components may be appropriate alternatives and which must be avoided.

During the digestion process, proteins will be digested to single, di or tri amino acids by the gastrointestinal system, penetrate the intestine mucosa and then transported by the blood. The integrity and performance of the GI system prevents that entire or partially digested proteins go through the intestinal mucosa and reach the intestine lamina propria.

If partially digested proteins arrive to the lamina propria, they are recognised as non-self-molecules triggering an immune reaction. FRT assesses the magnitude of the reactions against different food components.

6. How to interpret the “+” signs behinds numbers in test results? Is there a normal range of IgE?

All pets respond differently to allergens. Some react strongly with very high immunoglobulin levels and have light or no clinical signs. Others react lightly producing low immunoglobulin levels, but with severe clinical signs. The
intensity of the immune responses is genetically controlled and they are individual. Each individual is different. No standard or expected values exist, this is the reason why every pet can only be compared to itself.

7. How reliable is FRT in assessing clinically significant immune reactions?

Plant proteins carry cross-reactive carbohydrate determinants (CCDs). CCDs are structures that trigger specific immune reactions in pets. Anti CCD reactions are not pathological or clinically relevant but if immunoglobulins against CCDs are not blocked, a false positive reaction in in vitro tests are observed.

Anti-CCD reactions are of all types; IgE, Ig1 through IgG4. The expected frequency is that about 75% of allergic pets, have detectable levels of anti-CCD antibodies.

FRT is the only food test in the market that include an anti-CCD blocking system providing thus accurate test results. Heska is the leader in this new and complex area.

8. What makes the Food Reaction Test a valuable test?

  • It is technically sound. FRT integrates the latest technical advancements.
  • It assesses the immune reactivity to food proteins.
  • Evaluates the underlying effect of food the pet is currently receiving.
  • Allows for the selection of alternative food component diets.

For veterinarians:

  • Confirmation of suspicion of a gastrointestinal related condition
  • Valuation of the diet the pet is currently receiving
  • A laboratory result to support a diet change in front of the pet owner
  • Indication of what food components have to be recommended for a diet change or elimination diet in a
    particular case

For pet owners:

  • An objective assessment to support a diet change as recommended by the veterinarian