How long should a cat be kept on a food elimination diet trial?
There is conflicting thought on this. Some pet experts say 12 weeks is necessary, but others say results can be definitive in six or eight weeks. Since it’s so challenging to keep pets on a food elimination diet trial, they say, forcing owners to conduct it for longer than necessary will only make them give up on the test before it’s concluded.
As challenging as it is, though, an elimination diet trial is really the only reliable method to identify the allergen.
A veterinary dermatologist will put the cat on either a novel protein or hydrolyzed diet. Expect your veterinarian to ask you in detail about your cat’s past and current diets, flavored medication and type of treats. Your veterinarian needs to be sure the new diet has no proteins to which the patient had ever been exposed and will be readily eaten by the patient.
The reason the proteins need to be something that your cat has never had before is because a food allergy always has a build up that takes awhile to develop. For example, lamb used to be considered a good allergy food since it was so uncommonly eaten. Now, however, it’s eaten regularly and the more exposure an animal has to it, the better the chance of her developing reactions to the antibodies. Today, rabbit, kangaroo and, occasionally, fish are the first diets of choice for most patients with suspected food allergies. There are many commercial novel protein diets on the market.
Hydrolyzed diets are also available, with hydrolyzed chicken- and soy-based foods being the most common. The idea is that proteins are broken down to individual amino acids (the foundations of proteins) and are small enough to avoid detection by the cat’s immune system and less likely to elicit an immune response as a result. Commercial brands are available. If you are going to feed a hydrolyzed diet, it is still best to avoid sources of protein, which your cat has eaten previously, because she might still have a reaction.