Magnesium is a very well-known mineral and is used by millions of people for its health benefits. Magnesium is required for the normal function of every cell in the body and is necessary for muscle and joint health, metabolism, energy levels, and a healthy nervous system. It is therefore an extraordinary mineral for horses since our horses need a lot of support for both their muscle function and their stress levels.
And, since grass and hay does not usually provide enough magnesium to meet their daily requirements horses often exhibit signs of deficiency such as irritability, muscle tension, muscle fatigue, spasms, nerve pain, and Insulin Resistance.
But even though magnesium deficiencies are common, your equine partner doesn’t need to be deficient to benefit from the numerous benefits of magnesium. Like all minerals, magnesium, when provided in therapeutic dosages, can help horses with a variety of different health conditions.
Let’s take a look at 3 of the most common uses of magnesium for horses:
1) Bone and muscle function
Sixty percent of tissue magnesium is located in the skeleton. It is essential for maintaining healthy bones by initiating the chemical pathway for calcium absorption. It helps to dissolve calcium in the blood for absorption into the tissues and bones. When magnesium levels are too low for a long time, it can lead to calcification of the bones and joints which can contribute to bone spurs, arthritis, and hoof pathologies.
While calcium is responsible for muscle contraction, magnesium is required for muscle relaxation. Deficiency signs include muscle spasms, cramping, fatigue and an irregular heartbeat. Magnesium can also be used therapeutically to alleviate muscle tightness, tension and spasms. As an anti-spasmodic, magnesium can also help relax the intestinal muscles during episodes of colic, both acute and chronic.
2) Conditions of the nervous system
Magnesium supports the nervous system by regulating neurotransmitters and facilitating nerve transmission. It is also heavily involved in managing the stress response by supporting healthy production of cortisol from the adrenal glands. Horses that are deficient in magnesium will often exhibit nervous behavior, anxiety, and a low threshold for stressful events. As a result, magnesium is commonly used as a natural relaxant for high strung or anxious horses during times of physical and emotional stress. It can even be used as a remedy for neurological conditions.
3) Sugar metabolism and energy production
Magnesium is also very important for carbohydrate or sugar metabolism. This can be especially beneficial for horses that are easy keepers or horses that are Insulin Resistant or have Cushing’s Syndrome (PPID). Magnesium plays a key role in converting glucose from feed to energy. If magnesium levels are depleted, the cells will be more resistant to insulin which is the hormone responsible for transporting glucose into the cells for energy.
Factors that can lead to magnesium deficiency in horses
- Insufficient levels in grass and hay
- The use of diuretics
- Toxic heavy metals
Now that you know more about the signs of magnesium deficiency in horses, what type of magnesium should you use?
When choosing a magnesium supplement for your horse it is important to know which one is going to get the best results. There are many different types of supplements out there and no two are created the same.
Let’s explore your options…
Minerals are naturally derived from the earth and are essential to sustain every physiological function in the body – human and animal. All minerals, including magnesium, are classified as inorganic elements because of their chemical properties and position on the periodic table.
However, when supplementing magnesium as a dietary nutrient there are two types available for horses that you should be aware of: organic and inorganic.
Organic magnesium for horses
Organic magnesium is the most bioavailable form for horses.
Common organic forms of magnesium include:
- Magnesium citrate
- Magnesium gluconate
- Magnesium bisglycinate
These magnesium compounds are considered organic because the magnesium is chelated or attached to a carbon containing molecule. Bonds that contain carbon more closely resemble the natural compounds found in plants and other living things. This allows them to be more easily recognized by absorption sites and transported from the small intestine into the bloodstream.The rate of magnesium absorption depends on the group that is chelated to magnesium. Magnesium citrate has a reported absorption rate of approximately 30% which is higher than many inorganic forms.
Inorganic magnesium for horses
Inorganic magnesium is the most common form found in equine supplements and horse feed, but it is also the least bioavailable compared to organic forms.
The two most common types of inorganic magnesium are:
- Magnesium sulfate
- Magnesium oxide
Both of these magnesium compounds are classified as inorganic because they don’t contain carbon in their chemical structure. As a result, the body doesn’t recognize them as naturally occurring molecules such as those found in plants. Consequently, they aren’t broken down as easily into smaller units for transport across the intestinal lining into the bloodstream. Magnesium oxide, for example, has been reported to have an absorption rate as low as 4%.
It is also worth noting that dietary minerals compete for absorption. After inorganic molecules are broken down into positively or negatively charged ions, they are attracted to certain binding sites on the intestinal lining. Ions from other minerals with the same charge can often interfere and prevent other inorganic minerals ions from binding.
This is further evidence that your horse is possibly only absorbing a fraction of what they are getting in any commercial feed program. It also explains why many horses still show signs of nutrient deficiencies even though they are regularly supplemented with a mineral mix and a complete feed.
Organic forms of magnesium are always superior for horses…
It is estimated that up to 20% of all horses and over 50% of sick horses are deficient in magnesium! It is therefore important to select a high-quality organic form that is bioavailable and will deliver maximum benefit.
Unfortunately, when horse owners are looking for a magnesium supplement for their horses, they will often choose magnesium oxide because it is less expensive than the organic forms. The price difference is because the oxides don’t require the extra processing to chelate the magnesium with a carbon-containing group.
However, it is our that experience that not only do horses do better on the organic forms of magnesium, but most horse owners are always glad they chose a higher quality magnesium supplement to get the results their horse needs.
How much magnesium does your horse need?
Most horses respond well to 1,500 mg daily of magnesium citrate which is usually enough to correct most deficiencies and to provide relief from stress, tension, or muscle tightness.
However, when using magnesium to relieve acute pain, colic, or muscle spasms, a loading dose of 3,000 mg daily can be given for the first few days, or as needed for comfort. Once the horse responds, the dosage can be lowered to 1,500 mg daily.
In summary, if you suspect that your horse is deficient in magnesium or if you think that they might benefit from the many amazing properties of magnesium, make sure to supplement with an organic form to ensure high absorption.
And remember, you should never have to feed a supplement forever. A course of 4 – 6 weeks is plenty of time for your horse to demonstrate the benefits and then you can reduce to a maintenance dose as required or use as needed.
I am an animal lover, health consultant, scientist and educator. I am passionate about delivering safe and effective health care to all animals but horses and dogs have a special place in my heart. I believe that through education and awareness of natural animal health we can drastically improve their quality of life and longevity. I invite you to join me on my quest to make the world a better place for all of them.
My horse is Insulin Resistant and also has Cushings, from reading your post I gather she would benefit from Organic Magnesium. Is there any down side to giving a horse magnesium if it doesn’t require it, or is already getting enough through other feed?
Thanks for your comment. There is no downside to using nutrients therapeutically. The key is to supplement only as long as it is demonstrating benefit. You never want to supplement one nutrient long-term if the condition isnt improving.
Thanks Elisha I have a 9 yr old rescue TB and although he has a 365 mineral and vitamin supplement plus a very good diet, I still feel he could be better..he’s always stiff since having kissing spine 2 years ago…the cold and damp doesn’t help.
I will try this and see how he improves and I will report back!
Sounds great! I look forward to your feedback.
I have been using a magnesium oil preparation… from mag crystals. Applying it to the body. Is this a good way for absorption ?
I have never tried that method of magnesium supplementation for horses so I am not sure how well it would absorb through the haircoat and hide.
Thank you Elisha for helping our animals in your quest for knowledge.
My 18yr. old warmblood mare is just recovering from insulin resistant laminitis. Do you think that it is a good time to do a course of magnesium citrate?
She has had it before, also we are finishing up the insulin spray and hormone boost.
Thank you for your kind words Cheryl. Our animals are the best teachers.
You can certainly do another course of Magnesium Citrate. Many horses benefit and it does help with IR and stress. One other nutrient that comes up a lot for IR is Vitamin B6.
I have been a magnesium user for years for myself and my horses. It’s interesting when you talk to other horsey people that don’t feed magnesium in there horse’s diet. If it makes me feel better then why wouldn’t it help my horses feel better. So glad you brought this up.
Thank you for your comment Karen! Yes, our horses benefit from the same nutrients as we do and of course nutrient deficiencies are one of the main causes of equine disease in the domestic horse population. Stay tuned to my blog for more info on how to help horses with single nutrients. Happy new year!
I have 2 mares.
The first licks and scratches her sides every time after eating like the digestion or food processing is itchy or feels funny. She loves to roll but not excessively but at least 1-2 / per day. We don’t think it’s colic as this has been going on for almost a year and has had vet checks. Sometimes her sides are sensitive but not always. She does have an old injury and scar on her right side so there may be scar tissue. Wondering if Magnesium may help relieve the itchiness or does it all sound normal?
The 2nd is a very hormonal girl and is surly at the best of times but much worse when in heat. Very girthy but otherwise healthy.
Could magnesium help in calming her?
I think Magnesium would be a great nutrient to start with for sure. Many horses do well on it. Magnesium can also help with cycling cramps as well which can benefit a lot of unruly mares. Because there is more going on in this case it is hard to say what is going on. If you would like specific guidance you can also consider having me do a full consultation. I would be happy to help you.