Some cats may have allergies to certain foods. This can cause skin itchiness, vomiting, or diarrhea. Today, our Orange Park veterinarians will discuss food allergies in cats, the symptoms, and what you can do to help.
What is a food allergy?
A food allergy is an adverse reaction that occurs when a cat's immune system overreacts to a previously exposed food substance. A cat with a food allergy to a specific ingredient must have consumed that ingredient previously. Food allergies most commonly affect the skin, but they can also cause gastrointestinal upset, resulting in diarrhea and/or vomiting.
You'll be happy to know that food allergies are uncommon in cats, affecting only about 1% of all cats. There is no evidence of a link between age, gender, or breed.
What foods are typically associated with a food allergy?
Beef, fish, chicken, and dairy are commonly associated with food allergies in cats. Before developing an allergy, a cat must have been exposed to a food ingredient. You should be aware that an ingredient a cat has consumed for a long time can still cause an allergy at some point in its life. There has been limited research in this area, and it is possible that other allergens have not yet been identified.
What are the symptoms of a food allergy?
Itching is the most common symptom of a food allergy. The itching can happen anywhere, but the most likely spots are the head and neck.
Other symptoms may include:
Because of the constant itching, skin lesions may also appear. These can include:
- Small crusts (miliary dermatitis)
- Self-induced trauma (sores due to biting, scratching, or licking)
- Self-induced hair loss (due to biting, scratching, or licking)
- Plaques (raised circular nodules)
Less commonly, your cat may also suffer from an upset stomach, which can mean diarrhea, vomiting, or both.
Are there risk factors for food allergies in cats?
Food allergies are influenced by genetic predisposition and are frequently associated with atopy (inhalant or environmental allergies). Atopy can develop in cats at any age after three months, and male and female cats are equally prone to food allergies.
How can a veterinarian diagnose a food allergy?
An elimination diet trial is the most reliable test for determining food allergies in cats. This test involves feeding a diet devoid of any proteins to which your cat has previously been exposed. This trial is expected to last at least eight weeks. A trial diet could include:
Veterinary hydrolyzed protein diet, in which the protein molecules are broken down to a size too small for your cat's immune system to recognize.
Veterinary novel protein diet that contains no products found in your cat's previous foods.
Home-prepared novel protein diet that contains no ingredients found in your cat's previous diets.
During the elimination diet trial, your cat must eat only the food that your veterinarian has recommended. During the trial, no other treats, supplements, or edible products should be given. The following step is to conduct a food challenge to reintroduce the cat's old food. If the cat's symptoms improve after the diet but return within one week after returning to their old food, they have been diagnosed with a food allergy.
Because chronic itching caused by food allergies can also be caused by external parasites, bacterial infection, yeast infection, or other allergies, additional testing to determine the cause(s) of your cat's skin condition is often recommended.
How are food allergies in cats treated?
Food allergies in cats are treated by feeding a diet free of allergens. Because of stricter quality control, prescription diets are preferred. Over-the-counter cat food may contain contaminant proteins. Retail pet foods may claim to be 'limited-ingredient' or contain allergens, but they are not produced using the same health and safety protocols as veterinary diets.
Regardless, once you've found a diet that works for your cat, you'll need to stick with it for the long haul, avoiding cat treats and other foods that contain the allergen. You'll be happy to know that the prognosis for cats with food allergies is generally good with careful dietary control.