Magnum's Rough Year: What I learned about insulin resistance (his) and denial (mine).

by Mary Tulin, with Kip Tulin, MD

“Is your horse insulin resistant?”

“No. Uh, what’s that?” I asked, feeling oddly defensive. I was chatting with a woman participating in a clinic at Freedom Farm last year (2015), a fellow Morgan fancier.

“It’s kind of like diabetes, “ she replied. “My horse has it, and mature Morgans are prone to get it.” Her Morgan horse, a handsome, trim gelding, stood nearby.

I quizzed her further, sure that my 15-year old gelding Magnum was perfect in every way and destined to be healthy and fit into old age.

“Well, I noticed Magnum had some little bumps,” she pointed to his side. “My guy had those, so I had a vet check him.”

Bumps? Yep, there they were. But there weren’t very many. And even though a few professionals (riding coach, saddle fitter, etc.) had pointed out Magnum’s occasional crestiness, I’d never worried. He was a lively, feisty middle-aged horse and I was sure he was fine. Perfectly normal.

Magnum and me, a few months earlier. 

Well… there had been that nasty thrush, earlier that spring. It hid beneath his frog very effectively until I had Jerry Schmidt look at it. In short, the thrush had gotten away from me, and Magnum was parked for a while while his hoof grew back in, after a thorough trim by Jerry. But a few other horses had also had unusual thrush, given the dry weather, so I assumed it was a thing. As in, one of those things that will pass.

For the most part, Magnum was a happy member of his herd, fellow geldings who loved to play and were generally nice guys.

Well… there had been Magnum’s reluctance to join in the frolic a few times. A new young herd mate seemed to have taken over Magnum’s ‘let’s party!’ role, and Magnum would stand by while his buddies reared and cavorted. And lately he’d been slower to greet me when I’d come to catch him. A deliberate walk, not the happy trot of yore.

I should say, I am a first-time horse owner and returnee to riding after 35 years. I tend to read a lot into Magnum’s behavior, and at the time, thought maybe he was a bit put out with me, with that slow walk to meet me.

Well… Magnum’s regular trimmer, Audrey Bryant, had suggested a couple of times over that previous year that Magnum might need to come off grass. I heard, but I didn’t hear. I thought maybe she was biased against grass, or something. And there was the thrush thing. And Magnum’s and my emotional relationship. And the positive aspects of his life in the herd.

No, I liked things the way they were.

All of which flashed through my mind that July day in 2015, as I questioned the fellow Morgan owner about insulin resistance. I wondered what test had determined insulin resistance —a blood test, she said, but not a very conclusive one. He'd been fine, except for the tell-tale bumps and crestiness. As is often the case, his was a diagnosis based on history and heredity, and a bit of an educated guess. She had taken him off grass, put him on a diet of hay and some key supplements, and he was doing great.

I heard, I filed it away in my brain, and asked her about her cool saddle. End of subject.

Or so I thought.

Over the next few weeks, late summer’s heat set in, and I wistfully noted that Magnum’s summer coat was fast shedding. Worse, his new coat seemed awfully warm for the weather. While not the shaggy winter look, it was kinda thick, and he seemed uncomfortable. Especially during classes and long trail rides, he was sweating a lot and seemed not quite his perky self.

I got this sinking feeling, and resolved to monitor the situation.

Then came the day I went to get Magnum, who stood at the far end of the pen, rear end towards me. His head was low as he swung it around to me. Oh no. He really isn’t feeling good, I thought. He followed me out of the pen slowly, head still low. Jess Crouch stood by. “He hasn’t seemed himself lately has he?” she said. “Maybe it’s time to give him off grass and see if it helps. Ask Mary if we can put him in a dirt pen.”

It was time to think about insulin resistance. What is it? I asked my husband, Kip Tulin, M.D., for a description. This paragraph showed up in my email:

Insulin resistance is an abnormal condition where the cells of the body no longer respond to the normal actions of the hormone insulin. Normally, the body digests carbohydrates and releases glucose into the blood stream. As the glucose rises, the pancreas makes insulin which tells the cells to take up the insulin and use it for energy instead of using fat stores.  This decreases the blood sugar and is called insulin sensitivity.  When this sensitivity declines the cells can no longer respond to normal levels of insulin and the blood sugar rises. The body responds by making even more insulin to try to regulate the glucose. Once this becomes chronic, it is called Type 2 diabetes (in humans), and can lead to something called Metabolic Syndrome, with high blood sugar, high cholesterol, high blood pressure, and a host of other problems.

Kip added that the attendant health problems are species specific. Diabetic people would have eye and kidney problems, for instance. Insulin resistant (IR) horses would tend to be overweight (though not all overweight horses are IR) or get fatty deposits (such as in the crest, but also elsewhere), and worse, laminitis and founder.

As our local nutrition expert, Barbara Noble has noted, our Pacific Northwest grass is very rich in sugar (as well as iron) and unlimited grazing can quickly lead to overweight and laminitis in many horses. Add to that a tendency toward insulin resistance, and you’ve got a horse in serious trouble.

My Magnum.

And me? As Kip would say, I was no longer Cleopatra, Queen of de Nile.

In the next installment (or two), I will tell the story of Magnum’s crash and recovery, with special emphasis on his feed, his feet (he basically had to grow a whole new set of hooves) and the basics of IR-induced laminitis.

But to finish this part of the story, Mary (Gallagher) quickly agreed to Magnum’s joining one of the ‘fat pen’ herds. There was a perfect trio of geldings familiar to Magnum, living in a dirt pen by the hay barn. Magnum joined right in, reassured the young firebrand who’d assumed leadership that he would be no threat, and gingerly walked around his new quarters.

It seemed like the perfect situation.

It wasn’t.

Read the next installment: Magnum’s Rough Year, Part Two: “Oh No, Laminitis!”