When spring comes, and the pastures are full of lush, green grass, it may be tempting to let your horse graze on fresh grass for the first time since before winter. After all, spring grass can provide your horse many of the nitrients he needs. However, the same grass can cause problems as well, such as obesity, intestinal upset, and laminitis. This is because domestic horses, unlike wild or feral horses, do not have graze over large areas of land to get enough eat. Most can stand almost in place all day. Furthermore, spring grass is full of sugars, protiens, and quickly fermented carbohydrates, unlike hay. Managing the time your horse spends grazing can prevent these such problems.
After eating only hay and possibly feed or grain all winter, any horse much be eager to feast on all the verdant grass covering their pasture. In fact, they may get too eager, eating way to much grass and even becoming overweight, a problem for horses who are just getting used to fresh green grass after a long winter. This affects the horse's overall health. Fortunately, this can be prevented by limiting your horse's intake of grass.
Unlike hay, young grass has lots of sugar, protien, and quickly fermented carbohydrates, a change that can cause problems in the intestinal tract if done too quickly. Signs include softer manure than normal, and in more severe cases, bloating, diarrhea, and colic. In the most extreme cases, the bowel wall may be damaged and laminits may result. This too can be prevented by limiting your horse's grass intake.
The most serious problem that is influenced by overeating of spring grass is laminitis, an ailment caused by eating grass high in nonstructural carbohydrates, such as fructan, sugar, and starch. Horses with insulin resistance tend to be prone to laminitis, yet any horse is at risk. Most commonly, horses get lamintis when it is dry or cold.
Limiting your horse's grass intake early in spring, gradually increasing it to the desired amount, is the best way to prevent these ailments. Start with only letting your horse graze for small amounts of time, gradually increasing it.