Written by: Lucas James

Magnesium for Cats

Cat Health

Last Updated:

Magnesium for Cats: Essential Benefits and Optimal Sources Magnesium is an essential nutrient for cats, playing a crucial role in their overall health and bodily functions. This vital mineral acts …

Cat Health

Magnesium for Cats

Written by: Lucas James

Last Updated on:

Magnesium for Cats: Essential Benefits and Optimal Sources

Magnesium is an essential nutrient for cats, playing a crucial role in their overall health and bodily functions. This vital mineral acts as a catalyst for numerous enzymatic reactions, contributing to the well-being of felines. However, it is essential for cat owners to maintain a balance, as both magnesium deficiency and excess can lead to health complications.

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Cats and Magnesium

Cats with insufficient magnesium (magnesium deficiency) levels may develop hypomagnesemia, a clinical disease resulting from this deficiency. On the other hand, excessive magnesium intake may cause other issues, emphasizing the importance of providing cats with nutritionally balanced and complete, high-quality food. When fed properly, cats can receive the appropriate concentration of magnesium to support their health.

Some natural food sources containing magnesium that are safe for cats include fatty fish, such as salmon and halibut, which also provide additional nutrients like omega-3s, protein, calcium, phosphorus, potassium, and vitamin D.

Importance of Magnesium for Cats

Magnesium plays a crucial role in a cat’s overall health, health care and well-being. This essential mineral is involved in several vital biochemical reactions within a feline’s body. As a cofactor, it aids the proper functioning of numerous enzymes that contribute to cellular respiration, energy production, protein synthesis, as well as RNA and DNA synthesis.

Cats with magnesium deficiencies are at risk of developing hypomagnesemia, a clinical disease resulting from low magnesium levels. Additionally, magnesium is necessary for maintaining electrical balance across cell membranes and helps regulate the production and elimination of acetylcholine, a neurotransmitter. Consequently, a low concentration of magnesium in the extracellular fluid may have adverse effects on a cat’s motor function.

To ensure optimal health, it is important to provide cats with adequate dietary sources of magnesium. Some food options high in magnesium include fatty fish such as salmon and halibut. For instance, a 3-ounce serving of cooked salmon contains approximately 25 mg of magnesium. In addition to magnesium, fish also provide omega-3 fatty acids, protein, calcium, phosphorus, potassium, and vitamin D.

However, it is essential to be mindful of the balance in magnesium intake, as excessive magnesium may lead to health issues as well. Providing a well-rounded, nutritionally balanced, and high-quality cat food is the best way to ensure the appropriate concentration of magnesium in a cat’s diet.

Sources of Magnesium in Cat Food

Wet Food vs. Dry Food

When it comes to magnesium in food, there are differences between wet and dry options. Wet foods typically have a higher concentration of magnesium compared to dry foods. This is because wet foods often contain fish, which is a rich source of magnesium. Dry foods, on the other hand, usually have lower amounts of magnesium due to the lack of moisture content and the higher carbohydrate content. It is essential to check the labels of both wet and dry food options to ensure that an appropriate level of magnesium is present to maintain your cat’s health.

Natural Sources

There are several natural sources of magnesium that can be found in cat foods. Some of these include:

  1. Fish: Fish is a popular ingredient in many cat foods and is rich in magnesium. Examples include salmon, sardines, and mackerel.
  2. Meat: Many types of meat contain magnesium, such as chicken, turkey, and beef.
  3. Dairy products: Some dairy products, like yogurt and cheese, can provide a small amount of magnesium, although they should be given in moderation to avoid digestive issues.

It is crucial to provide a balanced diet for your cat, which includes a variety of magnesium sources. Consulting with a veterinarian can help ensure your cat receives the appropriate amount of this essential nutrient.


In some cases, cats may require additional magnesium in the form of supplements. These can either be given as a separate tablet, powder, or liquid, or added to your cat’s food.

However, it’s essential to consult with a veterinarian before introducing any supplements into your cat’s diet. A vet can provide guidance on the appropriate supplement for your cat’s specific needs and recommend the correct dosage.

Magnesium Deficiency in Cats


Magnesium deficiency, also known as hypomagnesemia, is a relatively rare occurrence in cats. Since magnesium is essential for the absorption of nutrients like sodium, calcium, potassium, and vitamins C and E, its scarcity in the body can lead to improper absorption of these elements. Common symptoms related to magnesium deficiency in cats include:

  • Urinary tract problems: Cats with a deficiency may develop issues such as urinary tract infections, bladder stones, and cystitis.
  • Muscle weakness: Magnesium is crucial for muscle function; thus, cats with low magnesium levels may experience muscle weakness or even tremors.


To diagnose magnesium deficiency in cats, veterinarians use a process called differential diagnosis. This method considers various possible causes to accurately identify the condition. In some cases, decreased intake might occur due to the lack of magnesium in intravenous fluids for patients receiving long-term fluid therapy or dialysis. Hypomagnesemia is more common in critically ill cats and can lead to severe health problems if left untreated.


Treatment for magnesium deficiency in cats depends on the underlying cause. In some situations, the issue might be resolved through dietary changes and supplements. A few foods rich in magnesium that are suitable for cats include:

  • Fatty fish: Salmon and halibut, which contain substantial amounts of magnesium, omega-3s, protein, calcium, phosphorus, potassium, and vitamin D.

Excess Magnesium in Cats

Potential Risks

Excess magnesium in a cat’s blood, known as hypermagnesemia, can have negative impacts on the nervous, respiratory, urinary, and cardiac systems. This condition is rare, but it has been reported in cats with kidney failure that were receiving intravenous fluids.

Cardiac arrest can occur when blood magnesium levels are very high. Additionally, hypomagnesemia, or low levels, is common in critically ill cats.


To help prevent hypermagnesemia in your cat, it’s important to feed your pet a balanced diet that provides the appropriate amount of magnesium and other essential nutrients. Ensuring your cat has access to fresh water can also support their overall health, including the maintenance of proper electrolyte balance.

If your cat has existing kidney issues, consult your veterinarian for specific recommendations on the appropriate magnesium intake for your pet. Monitoring your cat’s health and following the advice of veterinary professionals can help reduce the risk of excessive mag levels and its related complications.

Special Considerations

Senior Cats

As cats age, their body’s ability to absorb and utilize nutrients like magnesium may decrease. It is essential to monitor your senior cat’s mag levels through regular vet visits to ensure they are receiving the appropriate amount in their diet.

A diet tailored to the needs of a senior cat can help maintain optimal mag levels. Providing food sources high in magnesium, such as fatty fish like salmon and halibut, can contribute essential nutrients to their diet. It is important to consult with your veterinarian to determine the specific dietary needs of your senior cat.

Heart disease has been associated with lower magnesium levels with more senior cats, according to this report. Best to check with your vet, and to also check on your cats immune system, muscle pain and any side effects that may occur.

Also Read – Taking Care of Senior Cats

Chronic Kidney Disease

Cats with chronic kidney disease (CKD) may experience alterations in their magnesium levels. Elevated magnesium concentrations, known as hypermagnesemia, can lead to complications like impaired nerve impulses and cardiac problems. On the other hand, low levels of magnesium in cats with CKD can still occur and require supplementation.

In cats with CKD, it is crucial to maintain a balance in their magnesium levels. Regular vet visits and blood tests can help monitor these levels and guide any necessary diet adjustments. Veterinarians may recommend a specific renal diet or suggest magnesium-rich food sources tailored to the needs of cats with kidney disease. It is important to follow your veterinarian’s guidance to ensure your cat’s health and well-being.

Magnesium Requirements by Life Stage

Cats need varying levels of magnesium depending on their life stage, as it plays a crucial role in the proper functioning of their body. Magnesium is essential for metabolic functions and is an activator for more than 300 enzyme systems, including those that involve adenose triphosphate (ATP), which transports chemical energy within cells for metabolism.

According to the AAFCO (Association of American Feed Control Officials), the minimum magnesium requirements for cats are based on two life stages: growth and reproduction, and adult maintenance. For growth and reproduction, the recommended minimum magnesium content is 0.08% based on the diet’s dry matter, while for adult maintenance, it is 0.04%. Alternatively, when basing the measurement on metabolizable energy, the recommended minimum amounts are 0.2g per 1000 kcal ME for growth or reproduction, and 0.1g per 1000 kcal ME for adult maintenance.

It is important to note that providing appropriate magnesium levels to your cat is not just about meeting the minimum requirements. There is a delicate balance between providing enough magnesium for optimum health and avoiding an excess that could lead to health problems. For example, excessive amounts of magnesium can contribute to the formation of struvite crystals in the urinary tract, a condition commonly known as Feline Lower Urinary Tract Disease (FLUTD).

Frequently Asked Questions

What are the symptoms of magnesium deficiency in cats?

Magnesium deficiency in cats can cause symptoms such as muscle weakness, twitching, and even seizures. This is because magnesium plays a crucial role in maintaining electrical balance across membranes and is involved in the production and elimination of acetylcholine, a neurotransmitter. If your cat displays any of these symptoms, consult a veterinarian for proper diagnosis and treatment.

Can magnesium supplements help with feline constipation?

Magnesium can act as a natural laxative, and some magnesium supplements may provide relief for constipated cats. However, it’s essential to consult with a veterinarian before giving your cat any supplements, as too much magnesium can lead to other health issues, such as urinary problems.

What is the recommended dosage of magnesium for cats?

It’s crucial to consult with a veterinarian for proper dosing of magnesium for cats. Dosages depend on various factors, including the cat’s age, size, health condition, and dietary needs. A vet can recommend the appropriate amount and form of magnesium to maintain your cat’s overall health and well-being.

Is magnesium citrate safe for cats?

Magnesium citrate is a common form of magnesium supplement. While it may be safe for some cats, it’s crucial to consult with a veterinarian before introducing any new supplements to your cat’s diet. The vet can recommend the correct dosage and ensure that your cat’s magnesium intake remains balanced and safe.

How does magnesium intake impact a cat’s health?

Magnesium is an essential nutrient for cats, acting as a catalyst for hundreds of enzymatic reactions in their bodies. Cats need the right amount of magnesium for optimal health – too little can cause clinical disease of hypomagnesemia, while too much can negatively impact their urinary health. Thus, it’s essential to maintain a balanced intake of magnesium by providing a well-rounded diet for your cat.

Are there specific cat foods that contain higher levels of magnesium?

Yes, there are cat foods that contain higher levels of magnesium. Some examples include fish-based cat foods rich in magnesium, such as salmon, mackerel, and sardines. Moreover, certain brands of cat food may have added magnesium to support a balanced diet. Always consult with your veterinarian to ensure that the cat food you choose meets your cat’s specific dietary needs.