Fescue Pastures:

Don't Judge a Book by the Cover

Jim Hamilton, DVM

Looking out over a lush meadow of fescue grass, one can only assume that horses view it as a field of chocolate ice cream. The disturbing truth is that like ice cream, fescue has some negatives to go with the positives.

Fescue grass has long been an ideal pasture grass known for its deep root structure and overall hardiness. In the south its use is limited because of the high moisture requirement and sandy soil's poor water holding capabilities. None-the-less an estimated 700,000 horses feed on more than 35 million acres of tall fescue in the United States every year.

The problem is that much of the grass, despite looking healthy, has a fungal infection that can have devastating affects on the grazing horse. The cost to the horse breeding industry is said to be in the millions of dollars. The fungus causes pregnant mares (grazing at grass) not to produce milk, retain the placenta and have delayed and difficult foaling. In addition, the fungus causes a photosensitivity (propensity to sunburn) on the fair-skinned areas such as the nose and pastern.

Even though the disease was recognized more than ten years ago, agricultural and veterinary experts had limited success in resolving the problem. The widespread use of the grass in much of the eastern half of the US has made cost effective eradication impossible. Fungus-free fescue seed is available, but according to agricultural experts it is both expensive and inferior when compared to regular seed.

When faced with no alternative but to graze a mare on fescue, it is recommended that she be pulled off pasture at least 3 months prior to foaling. This by no means prevents the problem, but may lessen the severity of symptoms. If the owner has proper breeding records and examines the mare frequently as foaling time approaches, problems will be recognized early. The veterinarian can prescribe medication which will help counteract the effects of the fungus if symptoms appear. In addition, your vet can help prepare for a possible dystopia (abnormal foaling). Prevention and proper planning are the real keys to this problem!

e-mail Dr. Jim Hamilton, DVM
Southern Pines Equine Associates