Standin' In High Clover
The first signs of spring are always a welcome sight. Trees are budding, songbirds abound, daffodils and lillies pop up everywhere and fields seem to turn from a dull yellowish brown to emerald green overnight. If you get excited at the first signs of spring, think how your horse must feel. To the equine species, spring is a smorgasbord of edible delights.
That lush field of clover, besides being tasty, can be a good source of nutrients for your horse; since it is an energy providing legume rich in acceptable amounts of protein and fiber. However, there are certain concerns a horseowner should be aware of.
According to Mike Murphy DVM, University of Minnesota, "Clover may be "too rich" at times for horses. The early rapid growth phase of some clovers, like other forages, may contain high amounts of soluble sugars. The soluble sugar content of the plant will decrease as it matures. These soluble sugars and other carbohydrates are sometimes associated with colics and founder in horses fed only pasture in the early spring."
"Two mold problems are generally associated with the common pasture clovers (red, white and alsike). These usually occur when the weather is above 80°F and humidity is above 60%. The most well known problem is "slobbers." Horses can literally fill several 5 gallon buckets full of saliva in one day. This condition is caused by slaframine, which is produced when red clover is infested with a mold. The mold is generally a rust color seen on the upperside of the leaf. This mold normally "runs its course" in 2 to 4 weeks, depending on weather conditions."
"The second problem in these clovers, black blotch disease, is not quite as well characterized, but has been reported in Minnesota, Washington, and areas of Canada. The mold literally causes black blotches to occur on the underside of the clover leaves, usually closer to the ground where the humidity is higher. Horses ingesting clover with black blotch have been known to develop excessive "sunburn," which is really a thickening and reddening of the white areas of skin due to liver damage. Black haired horses also get the liver damage but the "sunburn" is not visible."
"A third mold condition affects a different clover both white and yellow sweet clover. These clovers are not common in pasture mixes, but are more frequently seen along roadways. The problem arises not from clover in pastures but if sweet clover is harvested for hay AND gets moldy as the hay is baled. Crimping the sweet clover at cutting reduces, but may not entirely eliminate, this problem. An unknown mold converts the naturally occurring cumarol in the sweet clover to dicumerol a blood thinning drug. Horses may bleed if moldy sweet clover hay is a substantial amount of a horse's diet over a number of days. Dicumerol clears quickly, so taking the horse off the hay is the best choice. Injections of vitamin K or blood transfusions may be necessary in extreme bleeding situations."