Pet Keen is reader-supported. When you buy via links on our site, we may earn an affiliate commission at no cost to you. Learn more.

Home > Cats > 5 Foods High in Magnesium For Cats: Vet Approved Advice & FAQ

5 Foods High in Magnesium For Cats: Vet Approved Advice & FAQ

cat eating leaf of spinach

Vet approved

Dr. Lorna Whittemore Photo

Reviewed & Fact-Checked By

Dr. Lorna Whittemore

Veterinarian, MRCVS

The information is current and up-to-date in accordance with the latest veterinarian research.

Learn more »

Whole wheat, pumpkin seeds, nuts, dark chocolate, tofu, and avocado are all foods high in magnesium that humans should consume daily to meet their needs. But many of these options can be harmful to our feline companions, even in small amounts. So, what magnesium-rich foods are safe to give cats? Keep reading to find out!

Note: Before giving your cat any of the following options, it is strongly recommended that you consult with your veterinarian to make sure that it is safe for your pet to consume them and that your cat needs extra magnesium in their diet.


The 5 Foods High in Magnesium

1. Fatty Fish

cooked salmon on plate
Image By: amenic181, Shutterstock

Many types of fish are high in magnesium, including salmon and halibut. For example, a 3-ounce serving of cooked salmon contains about 25 mg of magnesium. It also provides high amounts of omega-3s, protein, calcium, phosphorus, potassium, vitamin D, and other nutrients.

If your cat is not allergic to fish, it can be included occasionally as part of a complete and balanced diet.

However, you should not give canned tuna to your cat. Tuna as an ingredient in commercial cat foods usually doesn’t cause problems, but canned tuna can cause digestive issues in cats.1 This is because it contains too many unsaturated fatty acids and not enough vitamin E or other antioxidants that can benefit your pet.

2. Beef Liver

beef liver on wooden board
Image Credit: Sergey Lapin, Shutterstock

Beef liver is rich in minerals, such as magnesium, iron, zinc, and phosphorus. Feeding small amounts of cooked liver to your cat is fine, but be aware that this food is also high in vitamin A. If your cat consumes too much, it could lead to vitamin A toxicity.2 Acute toxicity can lead to weight loss, nausea, tremors, convulsions, and even death.

However, cats’ vitamin A requirements are 10,000 IU/kg of food, and levels up to 100,000 IU/kg of food are generally considered safe.3 For reference, there is 21,100 IU of vitamin A in 81 g of beef liver. This means your cat would need to eat more than 385 g of beef liver to experience vitamin A toxicity.

Either way, it’s best to err on the safe side and consult your veterinarian before giving beef liver to your feline.

3. Chicken

Boiled chicken strips drained
Image By: mariannagraf, Pixabay

Chicken, especially chicken breast, has a good amount of magnesium and can be given to your cat occasionally. Be sure to serve it cooked and plain, without added seasonings like garlic and onion, which are toxic to your pet.

4. Spinach

Image Credit: Aline Ponce, Pixabay

Half a cup of boiled spinach contains 78 mg of magnesium. After pumpkin seeds, chia seeds, and almonds, this leafy vegetable has the most magnesium per serving. Unlike the other foods, healthy cats can safely eat a small amount of cooked or boiled spinach. However, it is best not to serve it to pets with kidney issues, as spinach is high in oxalates, which can lead to bladder stones.4

5. Watermelon

Image Credit: Hyun Chun Kim, Pixabay

Watermelon contains a significant amount of magnesium, in addition to potassium, vitamins A and C, and other antioxidants. Although cats are strict carnivores and do not need to consume fruits and vegetables, a small serving of watermelon (less than 1 inch) on occasion, if they like it, is safe. However, remove the skin and seeds to avoid any risk of choking.


What Is Magnesium?

Magnesium is an essential mineral that is found in large quantities in the body, mainly in the bones. The term “essential” means the body cannot make it (or make enough of it) to meet its needs. Therefore, it must draw the minerals from the diet in sufficient quantity to avoid deficiencies. Magnesium is necessary for several hundred vital functions and biochemical reactions of the human body, and the same goes for your cat.

Why Do Cats Need Magnesium?

Magnesium is essential for the proper functioning of nerves, muscles, and the immune system. However, cats only need a small amount of magnesium in their diet, the daily recommended amount-RDA, is 25mg.

Normally, cats that have access to good quality commercial food (dry or wet) should have no problem reaching the minimum daily levels of magnesium recommended by the Association of American Feed Control Officials:

  • 08%: Growth and reproduction minimum
  • 04%: Minimum maintenance for adult cats

What Are the Signs of Magnesium Deficiency in Cats?

Cats that are severely malnourished or have health conditions reducing their appetite may suffer from hypomagnesemia, which is a magnesium deficiency.

Hypomagnesemia is often accompanied by clinical signs that can range from lack of appetite to muscle pain, abnormal fatigue, muscle twitching or tremors, irregular heartbeat, or depression.

What Are the Effects of Excess Magnesium in the Blood?

Hypermagnesemia refers to abnormally high levels of magnesium in the blood. This clinical disorder is not that common in cats, but it can still cause serious complications in the nervous system and heart. Furthermore, cats with kidney problems are particularly at risk of suffering from excess magnesium in the body.



Cats need adequate levels of magnesium to be healthy. That said, most cats don’t need a large amount, which means you shouldn’t have to give them additional magnesium-rich foods to meet their needs unless specifically advised by your veterinarian. However, if you’re looking for occasional treats, any of these options should do the trick!

Featured Image Credit: phM2019, Shutterstock

Our vets

Want to talk to a vet online?

Whether you have concerns about your dog, cat, or other pet, trained vets have the answers!

Our vets