Editor’s note on June 15, 2015:

I wrote this post before reading Juliet Getty’s post on treating the insulin resistant horse. I no longer think counting calories is a good way to treat a laminitic horse. However, the included material related to calories is correct.

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We are killing our laminitic horses with calories.

That’s my conclusion. I had been thinking I had been starving my chronically laminitic horses for years only to discover I wasn’t even close.

I spent some time on the phone in November 2011 with an expert in equine nutrition, Dr. Scott King, a veterinarian who is now the equine products manager at Bayer Healthcare in the Animal Health Division. He used to be in charge of new product development at the Purina division that overseas equine feed and before that he was a practicing large and small animal veterinarian, who happened to be my vet.

He was doing me a favor in answering a question on a topic unrelated to calories, but that was all that was on my mind that week, and the conversation eventually turned to the appropriate amount of calories, officially kilocalories, that a horse should eat.

He said he believes that a maintenance horse needs fewer calories than the NRC recommendation of 15,000 calories that I’ve been quoting. He says the maintenance calorie requirement is 13,000, and he studied low-calorie diets for horses extensively, so he should know.

Prior to this conversation, I had taken my hay into my local feed store to make sure I had the weight correct. Using a USDA-calibrated scale, my flake was about 2 14/16 pounds, and I rounded up to 3 pounds for ease of doing the math, since flakes vary in size anyway.

Dr. King said brome hay tends to average 800 calories per pound. My brome was a bit more at 880 calories. Alfalfa is 900 calories.

If I multiplied 880 calories by 3 pounds, I got 2,640 calories for one flake.

I told Dr. King I thought that was impossible, adding: “That means that, if it’s raining and I decide to throw my horses an extra flake of hay to keep them busy while they stand in their shed, I’ve just given them several thousand extra calories.”

He said that’s right. Referring to horse obesity, he said: “I believe it’s all about the calories.”

As noted previously, each of my two horses had been getting six flakes of hay per day, or 15,840 calories a day.

They also had been getting a total of 1 pound of Purina’s Nature’s Essentials Enrich 32 (I weighed that, too), which has 1,100 calories per pound.

And the horses got a carrot a day, which was roughly 50 calories.

For a grand total of 16,990 calories.

If a pound of fat is equivalent to 3,500 calories, and the horses were getting 3,990 extra calories a day by Dr. King’s standards, it didn’t take much to figure out why the 14-2 hand pony looked wide enough to be two ponies.

Dr. King recommended that I ride one at a walk and pony the other, since my efforts to make them do real exercise had failed due to mobility issues.

Note that all my horses foundered while in work, and a horse in work gets to eat considerably more calories..

Once a horse is foundered and cannot work, you definitely are dealing with a whole new meal plan, and likely most of us are overfeeding our laminitic horses immensely once they turn into lawn ornaments, thus cementing their fate as chronically laminitic horses for the rest of their lives.

Knowing what I’ve learned about how many calories are packed into a flake of seemingly harmless hay — what I once equated to a bowl of salad for humans — I now have to believe overeating played a major role in these recurring founder cases, even if I find out that excess iron or some other environmental factor gave the horses a big push.