Even when we make sure to provide our cat with the most nutritious diet, the food Kitty ingests may not always agree with him or her. Substances in the food can trigger an allergic reaction, resulting in gastrointestinal or skin problems which can be difficult to diagnose. Here's what cat owners need to know about food allergies in cats and what to do if you suspect Kitty might have one.
Fact #1 - An allergy is the body's immune reaction to something in the food.The feline body - much like ours - has an excellent immune system. It identifies hostile bacteria, viruses, as well as toxins and fights them. The immune system's weapon of choice is an inflammation of certain tissues: a small and temporary price to pay when the body is under attack.
Unfortunately, an overzealous immune system can get confused and mark an innocent chicken or beef protein as the enemy. The resulting inflammation can cause various types of symptoms (we'll soon discuss those) and is generally referred to as an allergy. The protein that causes the reaction is called the allergen.
Fact #2 - Beef, fish and chicken are common allergens in cat foodIt can be difficult to tell which exact protein in a cat's food is the allergen. That's why veterinarians are more likely to address food sources - an animal or plant - as the potential allergens. A recent study indicated that the most common food allergens in cats are beef, fish and chicken.
Fact #3 - Food intolerance is not an allergyWhen a cat's lack of ability to digest a type of food causes an upset stomach, we call that a food intolerance. It's not an allergic reaction because it does not involve the immune system.
The most common example of a food intolerance in cats (and many humans) is that of milk. Milk contains a type of sugar called lactose. Adult cats can't process lactose very well, so ingesting milk is likely to give them an upset stomach and diarrhea. This is not a food allergy though. The body doesn't identify the lactose as a hostile agent - it just can't digest it.
Fact #4 - Food allergies in cats can cause gastrointestinal symptomsFood allergies in cats often cause chronic vomiting and sometimes diarrhea as well. Of course, not every case of vomiting or diarrhea indicates a food allergy, but once other causes are ruled out, an allergy is often the diagnosis.
Fact #5 - Food allergies in cats can also cause skin problemsIt may surprise you to learn that many times food allergies are manifested in the cat's skin, not the stomach. Veterinarians call these CAFR, an acronym which stands for Cutaneous (skin) Adverse Food Reactions.
Symptoms of CAFR can include itching, a general inflammation of the skin, and small fluid-filled lumps on a cat’s skin. The cat scratches the itchy areas, which often creates lesions and infections. These skin symptoms are often seen around the cat's head, neck and chest.
According to a recent study, in 3-6% of cats with skin problems, a food allergy is to blame. Another study found that prevalence was 6% of cases that presented skin inflammation and 10% skin hypersensitivities among cats referred to a veterinary hospital.
Fact #6 - A food allergy can take time to developA food allergy doesn't happen overnight. No one knows exactly why an allergy develops, but we do know that in some cases symptoms progress slowly over months and sometimes years. Just because your cat has been eating the same cat food for years with no issues does not mean he or she hasn't developed an allergy to it more recently.
Fact #7 - The best way to diagnose a food allergy is through an elimination dietWhile there are some blood and saliva tests that can be done, the only way to confirm a food allergy is by eliminating potential allergens from the cat's diet.
Your veterinarian will probably suggest a diet based on one or two ingredients for a period of several weeks to see if symptoms improve. If they don't, you'll have to try a different limited-ingredient diet to see if that helps. Once you find the culprit, your vet may suggest re-introducing it temporarily to see if symptoms return. If that happens - you know what type of food your cat must avoid from now on.
Fact #8 - Prescription food containing hydrolysed proteins can help diagnose (and treat) food allergiesYour veterinarian may suggest a hydrolysed protein diet as a form of elimination diet. The proteins in these formulas are broken down into smaller molecules which are far less likely to trigger an allergic reaction.
Fact #9 - Limited-ingredient cat foods are not necessarily hypoallergenicWith some cats, all it takes is a microscopic amount of the allergen to trigger a reaction. Eliminating every trace of the offending food can prove to be a challenge with some types of commercial cat food.
Unfortunately, store-bought limited ingredient foods are usually not "pure" enough for an allergic cat. Pet nutritionist Dr. Martha Cline, DVM, explains that the same production lines are often used to create various cat foods. For example, a batch of limited-ingredient chicken-based cat food could be contaminated with traces of beef used to make an earlier batch of cat food in the same production line.
Dr. Cline recommends using veterinary-approved hypoallergenic foods during food trials. Homemade foods are also an option, as long as owners take care to avoid cross-contamination with other types of food. A consult with a board certified veterinary nutritionist is recommended for cat owner home preparing food.
Fact #10 - The symptoms of a food allergy don't disappear overnightJust like it can take time for the symptoms of an allergy to build up, it can also take awhile for them to go away. Most affected cats will show improvement within a few weeks once the allergen is removed, with some taking up to 12 weeks. According to this study, 90% of cats will show signs of improvement within 8 weeks.
Fact #11 - Elimination diets must be followed to the letterA cat can be allergic to more than one type of food, so limited-ingredient hypoallergenic food diets must be followed quite strictly. Owners must watch out for the allergen - or traces of it - in every food or treat they give their cat.
Talk to your vet if you suspect your cat has a food allergyIf your cat suffers from chronic vomiting or skin problems - especially around the head and neck - talk to your vet about food allergies.
Don't try to diagnose food allergies on your own. Vomiting and skin issues can be caused by a multitude of other conditions and diseases. More urgent medical problems must be ruled out before addressing food allergies, so if your cat is showing any of these symptoms, talk to your vet and do not delay professional medical care.
Has your cat been diagnosed with food allergies? Share your story in the comments below or start a thread in the cat health forum to share what you have learned during your battle with this frustrating condition.