6 min read

Magnesium for Dogs


By Wag! Staff

Published: 06/06/2023, edited: 03/07/2024

Reviewed by a licensed veterinary professional: Dr. Linda Simon, MVB MRCVS

Save on pet insurance for your pet

You don't have to choose between your pet and your wallet when it comes to expensive vet visits. Prepare ahead of time for unexpected vet bills by finding the pawfect pet insurance.


Like humans, dogs need a nutritious diet to stay fit and healthy. That’s why so many pet owners spend hours researching brands and learning how to choose the best food for their canine. 

Dog food labels typically list ingredients and mineral content, including magnesium. But is magnesium good for dogs and how much should your canine be consuming? Keep reading this handy ‘magnesium for dogs’ guide to find out more, including:

  • Supporting heart and bone health, magnesium is one of the most important and abundant minerals in a dog's body.
  • Dogs generally do not suffer from magnesium deficiency or overdose as long as they're healthy and eating a balanced diet.
  • Factors like age and temperature can affect a dog's magnesium levels.
  • While some believe magnesium may help treat anxiety in dogs, no research has investigated or confirmed this theory.
  • Always consult your vet before giving your dog magnesium supplements (seriously, we can't stress this enough)


What is Magnesium?

While it’s common to discuss the best plant-based food for dogs or to seek out low-fat dog foods for an overweight canine, microminerals such as magnesium often get overlooked.

Magnesium is vital to your pet’s diet, however, playing a role in cognitive function, metabolism, cardiovascular function, nerve function and more. In fact, your dog needs to consume magnesium as part of their daily diet to avoid a magnesium deficiency

As with many other minerals in a dog’s body, like calcium, phosphorus and iron, magnesium is key to strong and healthy bones. In fact, magnesium is the third most common mineral in a dog’s bones after calcium and phosphorus. Magnesium also helps with muscle function, including keeping a dog's heart healthy.

Minerals such as magnesium are an important component of red blood cells. Magnesium also helps with the absorption other minerals, including potassium, zinc, and calcium.

two steel dog bowls side by side, the left bowl containing raw meat and the right bowl containing sliced, boiled eggs, greens, and vegetables

Why Does Your Dog Need Magnesium?

Magnesium for dogs is essential. This is because dogs can’t produce this micromineral on their own. Dietary support is therefore required to ensure your pet stays happy, energetic, affectionate, muscular, healthy and fun loving. Magnesium (Mg) might just seem like a word on the back of a dog food packet, but it can do so many wonderful things.

Here’s why magnesium is a must for your canine:

  • Bone health. Working alongside Vitamin K, calcium, iron and phosphorus, magnesium plays a crucial role in bone formation and development. Magnesium ensures pups grow big and strong and prevents the bones of older dogs from breaking. This mineral also keeps other nutrients in check, regulating calcium, vitamin D, zinc and more in your pet’s body. 

  • Metabolism and energy production. Magnesium is involved with energy production at a cellular level. This means that every time your dog sleeps, catches a ball, snuggles with you, yawns or thinks, magnesium is needed to facilitate this transfer of energy. Amazing isn’t it? The right magnesium dosage for dogs is therefore vital and the amount required depends on the age, size and breed of your dog. A Welsh Sheepdog, for instance, might require more magnesium than a more sedentary dog. But also seek advice from a veterinarian.

  • Muscle function. Magnesium helps a dog’s muscles relax and contract, allowing them to stay mobile and reach peak physical fitness. The right diet as well as any relevant or recommended magnesium supplement for dogs helps to prevent ailments such as muscle weakness, spasms and cramping.

  • Nervous system support. Magnesium for dogs supports brain function and makes sure messages can flow from the brain to the rest of the body correctly. It can also help to calm a nervous or anxious dog by promoting normal neurological function.

  • Enzyme reactions. The presence of magnesium is vital for the activation of hundreds of enzymes that assist with everyday life processes. Put simply, without magnesium, the body just wouldn’t be able to operate as it should.

  • Heart health. Magnesium is often recommended for improving heart health and supporting heart disease in dogs. From maintaining regular heart rhythms to ensuring blood pressure stays within the normal range and promoting healthy cholesterol levels, magnesium is vital.

  • Hormones. Hormone-related functions rely on magnesium. This makes magnesium crucial for mood regulation, breeding programs, pregnancy and more. Indeed, research suggests that proper levels of magnesium during pregnancy can prevent the uterus from prematurely contracting and inducing labor.

Food Sources of Magnesium for Dogs

Magnesium for dogs can be found in a wide range of food sources that are safe for dogs to eat. These include:

  • Fish (salmon, mackerel, pollock)
  • Organ meats (liver, heart, kidneys)
  • Bone meal — defatted, dried and flash-frozen animal bones ground to a powder
  • Beans (black beans, green beans)
  • Whole grains (brown rice, whole wheat, barley)
  • Vegetables (spinach, cucumber, peas)
  • Fruits (pumpkins, bananas, cantaloupe)
brown and white terrier dog lying on a pillow under a blanket wearing a blue water bottle on their head and a thermometer in their mouth

While magnesium for dogs is essential, they don’t need very much to stay healthy. According to the Association of American Feed Control Officials (AAFCO), an organization that creates nutrient profiles for dogs, magnesium should comprise 0.04% of your dog’s dry-matter died. Dry matter refers to dog food that’s had all moisture content removed.

This equates to about one milligram of magnesium per day.

If in doubt, always contact your veterinarian to avoid a magnesium deficiency in your pet, or (in rare cases) hypermagnesemia — a magnesium overdose.

hand holding a beige supplement in front of a brown and white terrier dog sitting on a wood floor

Signs of Magnesium Deficiency in Dogs

The right magnesium dosage for dogs is important. A lack of this nutrient can lead to a magnesium deficiency known as hypomagnesemia. This is rare, usually occurring in seriously ill dogs. But it’s important to be aware of the signs, especially if you’ve noticed a distinctive change in your dog’s appearance, energy levels or personality. 

While there are few obvious symptoms of magnesium deficiency, they may include:

Magnesium may also cause a deficiency in other minerals, primarily calcium and potassium.

Magnesium deficiency may also increase the risk of heart attack. One study involving 13 Beagles fed a low-magnesium diet found that a higher volume of heart muscle tissue died in deficient dogs than dogs fed adequate amounts of magnesium.

The magnesium-deficient Beagles also showed signs of behavioral issues like excessive barking and restlessness.

Treatment of Magnesium Deficiency

A magnesium supplement for dogs tends to be the treatment option of choice. This can be given orally or intravenously. Magnesium-deficient dogs may also require calcium and potassium supplements to treat other nutritional deficiencies.

Magnesium citrate for dogs is a chemical compound consisting of magnesium and citric acid. This is often used in pet products and supplements as a source of magnesium and can help dogs with low magnesium levels.

Signs of Excessive Magnesium in Dogs

Is magnesium bad for dogs? Only in certain cases. Excess magnesium in a dog’s body is known as hypermagnesemia. This is incredibly rare and occurs after a dog has ingested a substance containing high levels of magnesium chloride (like deicing chemicals). Hypermagnesemia can also happen if a dog is receiving an IV and has kidney failure, making them unable to absorb minerals.

Possible symptoms of magnesium overdose in dogs include:

*Cardiac arrest may occur when a dog’s magnesium levels are very high. Contact your vet immediately if your dog is showing signs of hypermagnesemia or respiratory distress.

Can You Give a Dog Too Much Magnesium?

If you’re worried about accidentally giving your dog too much magnesium, don’t fret. Most dogs tolerate magnesium well and any excess magnesium will pass through the urine of a dog with healthy kidneys. A dog with kidney disease, however, should not be given a magnesium supplement for dogs. This is because their kidneys can’t dispose of it, which could quickly lead to an overdose. 

Always consult your vet before giving your dog magnesium supplements. It’s also worth taking out pet insurance and Wag! Wellness to cover your pet’s routine healthcare routines.

Magnesium Supplements for Dogs  

Magnesium supplements for healthy dogs aren’t necessary if they’re getting enough magnesium in their diet, according to Dr. Callum Turner DVM, veterinary consultant with Wag!

"Supplementing magnesium wouldn’t cause any harm (but should be unnecessary in a dog which is fed a full comprehensive diet) as long as it is dosed within a therapeutic range."

Which dogs benefit from magnesium supplements?

A magnesium supplement for dogs shouldn’t be necessary if your canine is healthy. However, a supplement can benefit dogs with certain severe or chronic health conditions, including diabetes, epilepsy and heart disease. Malnourished dogs may also be given magnesium supplements to help with recovery.

The authors of a 2017 pilot study on magnesium levels on guide dogs and guide dog candidates also recommend supplements for:

  • Senior dogs
  • Working dogs
  • Dogs exposed to new environments
  • Companion animals in winter, especially those living with health conditions

Even if your dog falls into one of these categories, always consult your vet before offering a magnesium supplement for dogs to your canine.

Does magnesium help with anxiety in dogs?

Currently, no studies have investigated whether magnesium can help with anxiety in dogs. However, the same 2017 pilot study we mentioned earlier found that stress and environmental factors — like temperature, atmospheric pressure, and physical exertion — can affect a dog's magnesium levels.

The study found that magnesium levels:

  • are typically higher in summer and lower in winter
  • were lower in dogs enrolled in beginner training classes compared to dogs taking advanced classes
  • were lower in dogs forced to exercise, regardless of the season
  • may vary depending on the dog's age

All dogs in the study were fed the same food, which means the fluctuations in magnesium levels weren't caused by their diet.

If any behavioral changes were observed as a result of magnesium intake, the authors didn't comment on them in the study. More research is needed to confirm how magnesium goes hand in paw with a dog's stress levels.

Got questions about your dog's magnesium intake or dietary needs? Get answers in as little as six minutes on average with Wag! Vet Chat!

Wag! Specialist
Need to upgrade your pet's leash?

Learn more in the Wag! app

Five starsFive starsFive starsFive starsFive stars

43k+ reviews


© 2024 Wag Labs, Inc. All rights reserved.

© 2024 Wag Labs, Inc. All rights reserved.