Downside to Feeding Alfalfa Hay to Horses

If you live in Arizona, especially southern Arizona, your hay choices are often limited to two: alfalfa or Bermuda. Usually cheaper by the bale, alfalfa is often the popular choice for feeding horses. Due to its much higher protein level it's said to make a horse "bloom" and often doesn't require any added grain to add weight or energy to the horse. Yet most people never realize the downfalls associated with alfalfa hay.

I first began encountering one problem associated with alfalfa hay in the late 90's known mainly here in the southwest: enterolith stones. These are stones formed in the horse's intestines that can eventually cause blockages leading to colic or even death. The stones can grow in size to at least that of a grapefruit or even bigger. The high levels of protein, magnesium, and calcium contained in alfalfa hay contribute to the formation of these stones.

Over about a one year period my mom's mare passed over 60 enterolith stones ranging in size from a bit bigger than a pea to almost the size of a ping pong ball. From their smooth sides we knew she carried more. Yet her bouts of colic and passing stones stopped shortly after the alfalfa hay was removed from her diet.

Horses can also be allergic to alfalfa hay. I've seen bloody noses just from eating a small handful of alfalfa. With larger amounts I've seen huge edemas (swellings) across the entire belly that were hot and painful to the touch. Some of the horses are so sensitive to the alfalfa, even small amounts often found in supplements, or processed grains can bring on at least a bloody nose.

Due to its high protein levels, alfalfa can be hard on a horse's kidneys. This is especially true of older horses.

When a Paso Fino gelding came to us, he was suspected of having a neurological condition. He'd gradually lost weight, muscle mass and tone, begun losing coordination, and developed an edema across his belly with an oozing sore in the center. Despite repeated bouts of antibiotics, ointments, biopsies, and more, the vets could not figure out what was causing the sore and why it wouldn't heal.