Tuna Allergy in Cats

Just like humans, our cats can have allergies to certain foods or specific ingredients.  If exposed to a food allergen, it typically presents as a skin issue.  It can start out small as simply itching or licking excessively, but then turn into your cat losing all his fur in response to constantly scratching.  Or maybe his stomach seems upset after eating or he has been consistently losing weight despite a healthy appetite.  All of these things can be indicative of a food allergy.  If this sounds like your cat, you can discuss diagnostic and treatment options with your veterinarian. Once the allergen causing food is removed from his diet, his symptoms should subside and he should have a good prognosis of recovery.

While we have been taught cats love fish, tuna is not the best one for him.  If you feed your cat tuna on a regular basis, discuss possible side effects with your veterinarian.

Symptoms may include:

• Alopecia
• Pruritus (head, neck, ears)
• Erythema
• Papules
• Dermatitis
• Granulomas 
• Indolent ulcers
• Weight loss
• Vomiting 
• Diarrhea
• Abdominal pain
• Flatulence
• Inflammatory bowel disease
• Rhinitis
• Conjunctivitis
• Pancreas problems
• Liver problems
• Kidney problems 

Types

Allergies in our pets are usually caused by one of three things: food, the environment, or fleas.  If your cat has an allergy to something in the environment, it can be almost anything.  He can be allergic to pollen, dust, cedar, and even you.  If he is allergic to fleas, he can have a severe dermatologic reaction to just one single flea bite.  If he has a food allergy, it means something he is eating his symptoms.  A food allergy does not necessarily have a predisposition behind it.  It can occur at any age, to any breed or sex, and to any ingredient.

People often think human-grade tuna is good for their cat when in reality it is lacking important nutrients cats need in their diet. An allergy to tuna can be indicative of a type of food allergy.  A food allergy is caused by a hypersensitivity reaction to a food ingredient or additive.  Just like with any type of allergy in general, it is the immune system thinking something harmless is actually dangerous.  In this case, your cat’s system thinks the tuna is a threat and therefore the body responds in an attempt to protect itself.

Your veterinarian will perform a full physical exam on your cat.  This will allow her to take a proper look at his symptoms and rule out possible causes of his condition based on his symptoms.  She will also collect a verbal history from you.  She will want to know when his symptoms started, if they have been progressing, if you have been trying to treat at home with over the counter products and so on.  All these details can help the veterinarian with her diagnosis.

Naturally, the veterinarian will need to rule out other possible causes of his symptoms such as gastrointestinal parasites or flea bite hypersensitivity.  These things can also cause the skin and gastrointestinal symptoms so your veterinarian may run some basic diagnostic testing to rule out other suspected issues.  A fecal test will be recommended to check for intestinal parasites and possible skin diagnostics such as a cytology or skin scrape to rule out dermatological related causes.

Unfortunately there is no serum, blood, or intradermal test reliable for diagnosing food allergies.  The main way to come to a proper diagnosis is a trial and error dietary study; it is known as an elimination diet trial.  You remove tuna from his diet for a minimum of 12 weeks.  This gives his system time to remove any remaining ingredient from his system completely and hopefully his symptoms will begin to resolve.  Gastrointestinal signs typically resolve between 1 to 3 weeks.  Dermatologic symptoms take much longer to resolve as it takes the skin time to heal.  If his symptoms have resolved during this time, you need to reintroduce the suspected food item to get a confirmation.  If you offer the tuna to your cat again and his symptoms reappear almost immediately, you have your culprit.

Your veterinarian will also recommend blood work to check organ function.  If she believes tuna is the cause, she will want to evaluate the kidney and liver function with a chemistry panel.  She will also want to evaluate the pancreas levels with a specific test to see if pancreatitis is a secondary issue.

There is no treatment for a food allergy.  Instead, the veterinarian can offer secondary treatment to relieve your pet’s symptoms.  If he is experiencing pruritus and skin infection she may prescribe medications such as glucocorticoids or antihistamines to help with the itching and inflammation. She may also recommend a topical medication in the form of a liquid, ointment, or spray for you to apply directly to the lesions themselves

If your cat is experiencing any gastrointestinal upset from the tuna, your veterinarian can offer medications and therapies for it as well.  There are anti-vomiting medications, anti-diarrheal, and medications to calm the GI tract she can administer to your cat.  His symptoms will determine his treatment protocol.

If he has pancreatitis, there are specific medications she will prescribe to address it.  Depending on the severity of his condition, he may need to be hospitalized for therapies and monitoring.  If he is experiencing any type of liver or kidney issues or failure, it will also require treatment and possibly hospitalization.

Finding the source of your cat’s allergy is ideal.  By determining it is the tuna causing your cat’s symptoms, you can remove it from his diet and prevent his symptoms from continuing.

The severity of your cat’s symptoms will determine his recovery.  If he is experiencing mild gastrointestinal symptoms and skin related symptoms, he should recover very well with proper treatment.  If he developed pancreatitis, liver failure, or kidney failure, his prognosis of recovery declined.  The wisest thing you can do is talk to your veterinarian about your cat’s diet before you offer him any type of human food.