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What is Equine Insulin Resistance

What Is Equine Insulin Resistance 

It was thought 30 years ago that horses were immune to the affects of IR or Diabetes. Horses are alleged to have been on planet Earth for 4 million years. So why in such a relatively short period of time are horses so dramatically compromised by diabetes? What is Equine Insulin Resistance?

Many would say that the grasses have changed and are no longer the same. Which may be true. But to collapse the horse which has been capable of adjusting to it’s environment well enough to survive 4 million years….I disagree!

The cells of the horse can only accept and use so much glucose into energy for bodily functions or fat which is stored energy. When the cells can no longer receive or accept anymore glucose because they are filled to the brim with unused glucose, the cell wall becomes ‘Insulin Resistant’. Therefore the concentration of circulating glucose in the bloodstream gets higher and higher.

In very simple terms the cell wall “just says NO” to the affects of insulin. They refer to this loud “NO” as Insulin Resistance.

IR horses typically have no energy, frequent urination, mares will have cycling difficulties, can not catch or carry a foal, their eyes can be cloudy, they sweat profusely with very little work. Their coat lacks luster and is typically longer and some times seemingly curly and slow to shed in the spring or summer. These signs and symptoms are not to be confused with Cushings. IR and Cushings are two completely different disease processes . They are not mutually exclusive.

A horse may be IR and not have Cushings, or have Cushings and not IR, or they may have both. A blood test can rule out or confirm. The IR horses hooves tend to be more prone to laminitis and founder and their immune system is generally very poor, making them more prone to other systemic infections. Many of these horses will test negative for Cushings.IR horse’s blood levels are, as one might expect, high in both glucose and insulin and the blood panels are all messed up because this horse is not metabolically balanced.

If your horse is IR or metabolically challenged due to a diet of processed food….you will generally see a fatter horse with fat deposits behind the shoulder, along the spine and rib cage, at the dock of the tail, around the sheath, in front of the udder, on the rump and the crest. These fatty deposits may feel hard to the touch.

Many horses thought to be IR and/or Cushings may be HYPO-thyroid. For more info on this, visit the Equine Insulin Resistance & Equine Hypothyroidism page.

Why we are seeing IR in horses in epidemic numbers

Horse owners in recent years have been introduced and marketed to more and more commercial foods which typically contain a great deal of byproduct waste. This byproduct waste material is what remains of the original whole food which is processed for human consumption. For Example: wheat middlings or wheat milrun, rice bran, beet pulp, soy bean hulls, soy oil, soy meal, Distiller’s Dried Grain solutes, feed grade molasses, ground corn, Distiller’s fermentation solutes, ground cotton seed, almond hulls, flax meal…on and on.

The processing of these foods materials removes the vast majority of the food’s natural qualities such as their antioxidative qualities, the phenolic compounds, dietary fiber, the fats or oils, selenium, the phytoestrogens and more. These foods many times become “dead” foods, especially the foods which have been stabilized to prevent them from going rancid. These are also called Hollow Calories.

Byproduct Waste

This byproduct material is digested very quickly and the glucose is released very quickly into the bloodstream. Another way this phenomenon is described…the glucose index will spike. When this high glucose level is elevated the pancreas will produce more insulin, in the horse who has been grazing for 4 million years for 18 hours a day in it’s environment, naturally produces insulin 24/7. Insulin triggers the cell walls of the horse to freely accept glucose or sugar from the bloodstream.

Please read those feed labels…if you see that the first 6-7 items are byproduct waste products…that is what you are feeding your IR horse or soon to be IR horse, per volume. Those vitamins and minerals in a 50 pound bag of feed are not very much volume wise. The vast majority of that bag of processed feed by volume is byproduct waste, wheat middlings or wheat milrun, rice bran, beet pulp, soy meal, soy hulls, soy oil, Distiller’s Dried Grain solutes, feed grade molasses, Distiller’s fermentation solutes, almond hulls, ground corn, flax meal…etc

Negative Energy Balance

Many of these IR horses suffer from Negative Energy Balance….insofar as this horse is metabolically deficient, the horse thinks it will get what it needs metabolically from the next bite. This metabolic status creates a physical, emotional and mental panic….the horse appears to be singularly focused on food and the acquisition of food. Many of these horses are on low starch diets, their forage is soaked and a host of ever changing supplemental ingredient amounts. The horse acts as if it is being starved to death.


Your IR horse’s cells and bloodstream are packed full of energy….called glucose or cellular energy. Your horse needs to burn off the cellular energy, after which the cells become more receptive to the effect of insulin, your horse’s glucose blood levels drop and then your horse’s body begins to convert stored energy, which is fat back into glucose to give your horse more energy for bodily functions and exercise. The horse engine should be started every day, the IR horse’s engine MUST be started everyday.

Equine Challenge™ IR Protocol

In order to address this diet related condition…one must restore the metabolic balance to the horse which can only happen if we remove the processed byproduct waste as described earlier. When more whole foods are returned to your horses diet, the digestion will be slowed and your horse will be in a much better position to adjust to the glucose levels… must restore the metabolic balance with the forage specific Equine Challenge™ Vitamin and Mineral package and the rest of our IR protocol for IR horses.

Please contact us

  • If you are unhappy with the current progress of your IR horse given the IR protocols you are using
  • If you feel as if your IR horse is getting no where very slowly
  • If you are considering putting down your IR horse
  • If your IR horse is just living and not thriving given your current program
Hi Mackie, As of 12/6/10, Taps is doing so well and the IR protocol is keeping her fit and sound, at 23 years of age. Before I found your product, Taps had been lame off and on for about 9 months from laminitis (not the first time and she had rotated, but fortunately, with natural trimming, she's almost ground parallel now!) and although the lameness was getting less frequent, nevertheless, it persisted UNTIL I STARTED your protocol! Not only did she lose weight (especially the fat deposits !) she just seemed to be all around in better spirits (the picture shows a leaner horse than when the protocol was started). She has now been on your product for almost a year and we will continue on it from now on. Thank you Mackie for your product and the time you take to research this important health issue. Sincerely, Karen A. Smith Burbank , CA
What Is Equine Insulin Resistance
Karen A Smith
Burbank, CA
Dear Mackie and Kathy I wish I had a before and after picture of my horse, but actually the difference in not so much in his appearance (except his head sagged and he didn’t move at all) but in the way he, feels, acts and is now appearing balanced and happy. Mercury, my 19 year old bay Connemara-Thoroughbred gelding, suffered greatly after his 31 year old Golden Palamino sweetheart, Patty, passed on December 15, 2008. He went downhill pretty quickly, and by mid-January, he was in full-blown depression, Insulin Resistant, and laminitic. He was completely disinterested in his Welch Mountain Pony friend and was thin instead of over-weight. A complicated situation, to say the least. The usual blood tests and x-rays were run confirming the above diagnosis. Luckily, after many phone calls to friends, I was directed to Equine Challenge™ as several of the horses from Mercury’s old dressage barn had also suffered from some sort of I.R./Cushings type of symptoms and they had completely converted to Equine Challenge™ with great results after trying many of the usual tactics (beet pulp, rice bran, etc.--which Mercury had been on also). I contacted Mackie right away and was taken in with great interest as if my horse was his. I sent him pictures of Mercury’s feet, he worked with my farrier and me to move quickly and efficiently on my horse’s behalf. It worked. With a full conversion to the Equine Challenge™ I.R. recommended diet of EC Flax, Probiotics, and Vitamin/Mineral Grass formula, plus hay and white salt; more frequent hoof trims; lots of TLC; my horse is back to his old self. It blew away the vet when she saw him looking so well so quickly. In fact, since using the total supplements including Equine Challenge™ Laminae 911, he is better than his old self. He’s more responsive, supple, and available for closer interaction with me or my daughter because he is just plain feeling better these days. Enter Laminae 911: With the introduction of Equine Challenge™ Laminae 911, I can now say that Mercury is completely asymptomatic; no laminitis symptoms at all. We are riding and playing with NO down days. I did decide with the onset of the lower winter temperatures and considering his age, to also put him on a low dose of Equine Challenge™ Joint. The total picture is of a healthy, sound horse. To see my 19-year-old Mercury run and play vigorously for 10+ minutes straight with his 7-year-old pony friend on a steep terraced hill with no hitches in his giddyup during, after or the next day, makes my heart leap with joy! Additional benefits: In our household, we love probiotics. I even make my own using a culture and young coconut milk on occasion. However, our other animals, including the dog, cat, chickens and alpacas, are eating Equine Challenge™ Probiotics every day now. The EC Flax is also great fiber for all. The huge benefits rest in happier stomach flora (happier stomach and GI tracks make for overall happier beings), lower vet or medical needs, lower parasites, longevity and beautiful coats (fur, hair, fiber (alpacas), feathers, etc.). Thank you, Equine Challenge! Thank you Mackie and Kathy!
Pam Guettler
Damascus, Oregon
I have a beautiful Morgan mare named Patina, she has the most wonderful personality, but when I first bought her I started noticing she didn’t have a lot of energy, When I would turn her out she would go around the arena 1 or 2 times and then join up. She also had some fat deposits around her neck, a very hard and thick crest, fat at her withers and her belly was pretty big. I also noticed the winter coat was coming in very thick, long and curly. Even though I could see this expressive personality she just didn’t seem quite right. I had her blood tested and she came back significantly IR. I immediately spoke with Mackie & Kathy and started her on the Equine Challenge™ IR protocol. She had been on Equine Challenge™ for a few weeks at this time and was gaining some energy. After only 2-3 weeks of being on the IR protocol she was showing a significant change in her behavior. She was losing the fat deposits and her beautiful Morgan crest was softening and she would run like crazy in the arena when I turned her out. I would take her out on a trail ride and she would go at that great Morgan trot forever. The loss of some of that thick coat has been coming off like you wouldn’t believe, I could have covered several horses with the amount of coat she has lost even in these cold months of winter, oh she still has a wonderful winter coat but it is not so thick and curly. I had her blood tested after a little over 12 weeks of being on the protocol and her IR levels had dropped by over 200 points. I am so grateful to Mackie and Kathy for the help with her. I cry every time I think what if I hadn’t known about Equine Challenge™ and not had the opportunity to know Kathy & Mackie. Thank you both for the love you have for horses especially the Morgan (I wouldn’t have mine if it weren’t for you) and the diligent on going work you do to make sure lots of horses are the best they can be without having to be on medicine. Patina’s life will be so much better and longer with Equine Challenge™ and The Hartwig’s!
Equin Insulin Resistance and hypothyroidism
Rita Johnson
Prather, CA
Dr. Mackie, Anna is a 27 year-old Arabian mare, which was treated for Cushing Disease beginning April 2008 with Pergolide. From April through October, Anna had gotten progressivley worse. She was depressed, in pain, increased weight, swelling of the legs and various other edemas, anemic, and her blood work showed that she was desending. In October, Anna developed Laminitis and I was asked to double her Pergolide. Three days later, she foundered. An abdomon ultra sound showed that she did not have tumors or any other visable disease or abnormality other than an abnormal layer of fat. At this point, I cut back to her original dose of Pergolide. Over the next eight weeks, she was in severe pain, did not move more than 20 feet at a time. She only came out of her paddock twice during this time. The good news - eight weeks after Anna foundered, I was introduced to Dave Fitton. Under his guidence, we pulled her shoes and put her on Equine Challenge™ Grass. After three weeks, we added Equine Challenge™ Probiotic. She is doing amazingly well and I believe the change has literally saved her life. It might be important to note that I discontinued Pergolide (of own decision) slowly and was off the medicine within one week of starting Equine Challenge™ Grass. Three weeks after this new program, I could pony her in the sand arena and was able lead her on the trails for 20 minute walks. It has been one month and she trots on her own. David, an apprentice of Dave's in the Felon/Scotts Valley area, assisted us in Anna's recovery. He suggested that I reach out to you about working on reducing her fat deposits. Rather than looking as if she were full-term, she now only looks over-weight. THANKS for the teamwork. It has been a six-month struggle where we thought she would need to be put down. Many Vets and other equine professionals were perplexed and hopeless.
Donna Anderson
San Jose, CA
Equine Challenge™ Saved the Day. I went out to feed the horses one morning and what I saw was an absolute shame. My young sorrel gelding, with no kind of warning, was four-footed gimpy and lame. We called up the vet and she confirmed the reason: IR-induced laminitis, much to our dismay. Although it was January and mid-winter season, we were advised to start soaking his hay. It didn’t take long for this job to get old though we tried our best to make it sort of fun. That winter faucet water was frigidly cold and wet, frozen hay weighs a ton. We’d have to soak his hay for the rest of his life, a duty of love we’d better not shirk. It was too much heavy lifting for my darlin’ wife so I did the lion’s share of the work. I resigned myself to this back-breaking chore and for months this life style I led. I filled buckets in advance, at least two or more so I’d stay a few feedings ahead. Then we met horse nutritionist Mackie one day and after talking with him, were elated. He advised us we would not need to soak any hay if we used the product he originated. His nutritional views changed our way of thinking. We tried Equine Challenge™ and we’re sold. Now the cold water is just for the horses’ drinking and our gelding’s good health is worth gold. Equine Challenge™ Supplements were the key to his cure. It’s a product I’m happy to endorse. I am done with hay soaking, that’s for darn sure. I don’t know who’s happier, me or my horse!
Equine Insulin Resistance and hypothyroidism
Harold & Diana Miller

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