Common food allergens in cats

Current domestic and foreign veterinary clinical statistics show that the top three most common food allergens in cats are beef, dairy products, and fish, which together account for more than 80% of confirmed food allergy cases.； The next most common allergens include chicken, corn, wheat, soybeans, and eggs. About 5% of allergy cases are induced by artificial antioxidants, food flavors, preservatives and other additives. Moreover, there are no absolute age or breed restrictions for cats with food allergies. Even if they have eaten ingredients for several years, they may suddenly trigger an allergic reaction.

Last year, I helped a fan troubleshoot his 3-year-old stuffed animal. The cat had been eating a certain popular chicken full-price food for two and a half years. Suddenly, he started scratching his face day and night. He had repeated rashes on his chin and had soft stools intermittently. The owner initially treated it as a fungal infection, but after more than a month of spraying and medicated baths, no improvement was seen. He even went through a full set of virus tests but could not find the problem. Finally, he did a food test and found out that he was allergic to chicken. The owner stared at the results and asked me repeatedly, "I've been fine after taking it for two years, so why am I suddenly allergic now?" ”, this situation is actually not uncommon. The cat’s immune system is not a dead program. A serious illness, stress, or even changes in immune status caused by age may cause its immune response threshold to deviate. Food proteins that were originally judged as “safe” are suddenly regarded as foreign invaders to be encircled and suppressed.

Oh, yes, let’s first clarify a concept that many people confuse: food allergies and food intolerances are completely different things. Many people think that cats are allergic to milk when they feed their cats milk and see diarrhea. In fact, 90% of cases are lactose intolerance - that is, the body lacks the enzyme to break down lactose and cannot digest it. It has nothing to do with the immune system. True food allergy is an immune-mediated reaction. In addition to gastrointestinal symptoms such as soft stools and vomiting, it will also manifest on the skin: non-seasonal inexplicable itching, recurring ear mites, conjunctivitis, local hair loss, and even severe asthma and facial edema, which can be mild or severe.

Speaking of which, there is another misunderstanding caused by marketing. Many people think that grains are the number one allergen for cats, but this is not true. According to clinical statistics, cereal allergy cases account for less than 10%, which is far lower than the allergy rates of beef and fish. Many grain-free foods add a lot of beef and deep-sea fish to improve palatability, which makes it easier for them to step into allergy minefields. I have seen many owners hurriedly switch to grain-free foods for allergic cats, only to have their symptoms become more severe. This is because they stepped on this cognitive pit.

There are indeed two different voices in the industry regarding how to check for allergens. I can’t say who is right or wrong. It all depends on what is suitable for your family’s situation. One group insists on the "food avoidance + provocation test" as the gold standard: stop all the food, snacks, and supplements that the cat currently eats, and replace it with a single protein source that it has never eaten before (for example, if it has never eaten venison or rabbit meat before, choose this). Feed it continuously for 8-12 weeks. After all allergic symptoms completely disappear, add back the previous ingredients one by one. As long as the symptoms recur after adding a certain item, you can confirm that it is the allergen. This method has the highest accuracy and does not require testing fees. It is a test of the owner's patience. During this period, no extra snacks are allowed. Many people can't bear it and give up halfway, which is quite normal. The other group recommends doing a serum-specific IgE test first. Although there is a 15%-20% false positive probability, it can quickly narrow the scope of the investigation to 2-3 ingredients without having to wait for two months. It is especially suitable for cats with severe allergic symptoms and skin ulcers from scratching. You can't let the little guy endure the itching, right?

Some allergens are really hidden deep and can easily be missed. I met a 10-pound fat tangerine before. All the staple protein was checked and there was no problem. However, ear mites appeared as soon as he ate egg yolks. At first, the owner thought it was because the ears were not cleaned properly, so he tried three bottles of ear drops to no avail. Finally, he accidentally stopped taking egg yolks for a week, and the ear mites went away on his own. After trying it twice, he got ear mites as soon as he ate it, so he was diagnosed with egg yolk allergy. There are also cats who are allergic to salmon oil, food attractants, and even preservatives such as BHA/BHT added to cat food. In this case, don’t insist on changing the protein source of the food. Directly switch to low-temperature baked food without additives or simply make your own. This can usually be alleviated.

In fact, there is no need to panic if a food allergy is diagnosed. It is not a serious disease that cannot be cured. Just avoid the corresponding allergen. Nowadays, there are many hypoallergenic foods and hydrolyzed protein foods to choose from. It is also very convenient for those who are willing to make homemade cat meals. I know several cats with allergies. After avoiding allergens, they became smooth and smooth, and they are still active and healthy into their teens. There is really no need to be overly anxious about this.