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Can cats eat canned tuna and mayo?

Quick Answer

Cats can eat canned tuna and mayo in moderation as an occasional treat. Tuna and mayo provide protein, fat, and calories, but too much can lead to nutritional imbalances. Canned tuna has high sodium levels and may contain mercury, while the fat content in mayo can cause stomach upset. It’s best to limit tuna and mayo to once a week or less. Offer small portions of a tuna “salad” using low-fat mayo, mixed with cat food for balanced nutrition. Consult your vet before feeding any human foods.

Nutritional Breakdown of Tuna and Mayo

Tuna and mayo can add interest to your cat’s diet, but both should be fed in moderation. Here is the nutritional breakdown for these foods:


Nutrient Amount Per 3 oz Canned Tuna
Calories 99
Protein 22 g
Fat 0.8 g
Carbs 0 g
Sodium 350 mg


Nutrient Amount Per 1 Tbsp
Calories 90
Total Fat 10 g
Saturated Fat 1.5 g
Sodium 90 mg

As shown, tuna is high in protein and omega-3 fatty acids, while mayo provides mostly fat and calories.

Benefits of Tuna and Mayo for Cats

Here are some potential benefits of tuna and mayo for cats:

High-Quality Protein

Tuna contains high levels of protein, which provides essential amino acids cats need. Cats are obligate carnivores and require a high-protein diet.

Healthy Fats

The omega-3 fatty acids in tuna support skin, coat, heart, brain, and joint health in cats. Mayo can also provide some healthy unsaturated fats when used sparingly.

Moisture and Flavor

The moisture from canned tuna and mayo can encourage hydration. Many cats also find the flavors quite palatable.

Occasional Treat

Small amounts of tuna and mayo can add interest, variety, and taste to a cat’s routine diet. It can be fed as an occasional treat or supplement.

Risks and Precautions

While tuna and mayo are not toxic to cats, there are some precautions to consider:

Mercury Levels in Tuna

Like humans, cats are susceptible to mercury build-up from eating too much tuna. Mercury can cause neurological damage with excessive intake. Choose low-mercury canned “light” tuna.

High Sodium Content

Canned tuna often contains very high amounts of sodium, which can be hard on cats’ kidneys. Look for low-sodium tuna packaged for pets.

Nutritional Imbalances

Tuna and mayo by themselves are not nutritionally complete. Feeding too much may lead to deficiencies or imbalances over time.

Gastrointestinal Upset

The high fat content in mayonnaise can sometimes cause stomach upset, vomiting, or diarrhea in cats. Low-fat versions are safer.

Pancreatitis Risk

The fat content in tuna and mayo raises the risk of developing pancreatitis in some cats. This is a potentially serious condition.


Some cats may have food allergies to tuna, mayo, or additives like onions or garlic. Watch for signs of allergic reaction when feeding any new food.

How Often Can Cats Eat Tuna and Mayo?

For most cats, tuna and mayo should be limited to no more than once a week or less. Here are some guidelines:

– For a treat, offer your cat a teaspoon of tuna/mayo mixture 1-2 times per month. Mix with their regular cat food.

– To supplement their diet, add 1-2 tablespoons max of tuna with a dash of mayo to your cat’s meals 1-2 times per week.

– Split one 3 oz can of tuna into 3-4 portions to limit mercury exposure. Don’t exceed 1 oz tuna 2 times per week.

– Choose low-sodium and low-fat/fat-free mayo. Limit to less than 1 tsp per 3 oz serving of tuna.

– If feeding canned tuna, make sure it’s made for human consumption, not cats, to limit sodium. Tuna for cats or dogs contains even more.

– If your cat has health issues, talk to your vet about appropriate tuna and mayo amounts or avoid completely.

Best Practices When Feeding Tuna and Mayo

Here are some tips for safely feeding tuna and mayonnaise to cats:

– Choose tuna canned in water, not oil, and made for human consumption. Look for low-sodium versions.

– Select fat-free, low-fat, or “light” mayonnaise. Avoid mayo with onions, garlic, or other seasonings.

– Mix a small amount of mayo into the tuna instead of dolloping it on top which could pose a choking risk.

– Refrigerate any leftover tuna salad and use within 2 days. Don’t leave it sitting out.

– Make sure your cat’s overall diet is balanced. Tuna and mayo should only supplement their regular cat food.

– Start with very small portions of tuna/mayo mixture and monitor your cat’s reaction.

– Never feed tuna or mayo raw – cook or mix with cat food. Don’t feed tuna or mayo alone.

– Keep an eye out for signs of food allergy or intolerance like vomiting, diarrhea, itching, or ear infections.

– Ask your veterinarian before feeding tuna and mayo to kittens under 1 year old, pregnant/nursing cats, or cats with health issues.

Healthy Tuna Salad Recipes for Cats

Here are some healthy tuna salad recipes you can mix up for your cat to enjoy occasionally:

Basic Tuna Salad

– 3 oz canned tuna in water, drained
– 1 tsp fat-free mayonnaise
– 1 tbsp cooked egg whites
– 1 tbsp cooked peas or carrots
– Pinch of dried catnip (optional)

Mix together with 1/4 cup or more of your cat’s regular food. Store refrigerated for up to 2 days.

Tuna Kitty Crunch

– 3 oz low-sodium canned tuna, drained
– 1 tsp olive oil mayonnaise
– 2 tbsp cooked quinoa
– 1 tbsp shredded cooked chicken
– 1 tsp crumbled freeze-dried fish treats

Combine ingredients. Serve topped with crumbled treats. Refrigerate leftovers.

Mediterranean Tuna Salad

– 3 oz low-sodium canned tuna, drained
– 1 tsp olive oil mayonnaise
– 1 tbsp cooked brown rice
– 1 tbsp cooked garbanzo beans
– 1 tsp minced fresh parsley

Mix together and store refrigerated up to 2 days.


In moderation, most healthy cats can enjoy tuna salad made with canned tuna and mayonnaise as an occasional treat. Limit the amounts to reduce risks like mercury exposure, high fat, pancreatitis, and nutritional imbalance. Choose low-sodium tuna and fat-free mayo when possible. Always combine tuna salad with your cat’s regular food for balanced nutrition. Check with your veterinarian before feeding any human foods to cats with medical conditions or sensitivities. With some precautions, a tuna salad treat can be a safe way to supplement feline diets and satisfy finicky appetites.