Grass founder happens when a horse is suddenly able to eat big amounts of lush grass (i.e. sugary, spring grasses) and their bodies are not prepared to handle it. During the spring the temperatures during the night still get cold which causes new grasses to store their sugars, raising their non-structured carbohydrate (NSC) levels. So what’s the big deal? A horse’s diet is designed to consists of less than 10% NSC. When all of those fresh spring grasses pop up, the NSC level can rise and lead to laminitis. Grass founder/laminitis occurs when the tissue connecting the horse’s hoof wall and their coffin bone (which is inside the hoof) becomes inflamed. Laminitis causes incredible pain in horses can can cripple them. Sounds pretty scary, doesn’t it? When I use to take horseback riding lessons, I would take my horse out to graze after my ride, but the whole time, I would be terrified that he’d eat too much grass and founder. Looking back now, I’ve realized how silly I was being, but at the time, I had read so many horror stories of these poor horses eating grass and going lame that I was convinced grass was evil.
Hopefully by now you’ve noticed the major flaw in everything that I’ve been saying. I’ve been looking at horse care and laminitis from a “traditional” horse care standpoint. Founder and laminitis are problems that many “traditional” horse owners face. But here’s the really crazy thing: wild horses almost never founder or get laminitis. And since wild horses and domestic horses are genetically identical, then there is something wrong with the way we are caring for our horses that is causing these crippling hoof diseases.
Another big cause of grass founder is “pretty pastures”. You know the ones I’m talking about: that stereotypical image that everyone has of horses grazing in a green carpet of completely uniform grass. Well, newsflash, that thick carpet of grass (and usually only one type of grass) is a breeding ground for trouble and has one big flaw: it’s just not natural. Wild horses of the Great Basin live in desert like areas where their forage is spread out, encouraging movement. In a thick, grassy pasture, a horse can stand in one spot all day to eat all the food he wants. A wild horse’s diet consists of variety; grasses, shrubs, weeds, and bushes--not one uniform type of grass. This variety prevents a horse from getting too much of one thing and makes sure he eats all of the vitamins and minerals that his body needs. It’s time to ditch that idea of a pretty pasture and embrace an ugly one. If a horse is encouraged to move and has variety (living like a wild horse) he is much less likely to founder.
Joe Camp, who uses Natural Horse Care with his horses has a great article about his horses who live in Tennessee (a.k.a. Founder Valley) and who have never contracted laminitis. http://thesoulofahorse.com/blog/why-are-these-horses-eating-hay/
I’ve begun to notice that so many health problems common in “domestic” horses rarely occur in wild horses. That means that it’s the humans who are cause the problems. If we, as people, can better replicate the environment where horses are genetically designed to live, we can help to prevent these life-threatening problems from ever happening to our horses.