Needle Grass and Horses: What You Need to Know

By Larri Jo Starkey
Courtesy of American Quarter Horse Association

Spear grass, Texas winter grass, needle grass – whatever you want to call it, this native grass poses a health risk to your horse

Lurking in your pasture, there’s a teeny tiny predator looking to wound your horse. Disguised as a native grass, this forage is capable of damaging your horse. It’s so small, you might not even notice it until the damage is done.

Needle grass is a common name for a species of grass from the nassella family, says Morgan Russell, a range specialist for Texas A&M AgriLife Extension Service. Needle grass is sometimes referred to as spear grass or Texas winter grass, but there are other species.

Needle grass isn’t among the plants poisonous to horses, but it does pose a danger. The tag “needle grass” can refer to any number of different species, depending on location, but they have one common end: They’re sharp.

Signs that your horse may have ingested needle grass are drooling and blood coming out of his mouth. When you open the horse’s mouth, you may find:

  • Blood in the mouth or around the corners.
  • Hay stuck between teeth and gingiva, especially in clusters.
  • Bad breath and red gums.

When treating a horse that has ingested needle grass, your veterinarian may:

  • Use a hemostat to pick the compacted, dried grass out.
  • Administer and prescribe painkillers and antibiotics.
  • Instruct the owner to use dry gauze twice daily to scrape grass from between the teeth as the grass works its way out. This process may be ongoing for a week.

How to Get Rid of Needle Grass

Because needle grasses are native, they are difficult to eradicate, especially if the weather has been hot and dry, killing off the more desirable plants. Native grasses are built to withstand the vagaries of climate.

Savvy pasture managers will avoid overgrazing their land.

“If you keep your pastures in balance, if you keep your grazing management in sync with your environmental conditions, then those plants should be minimal in the plant community, maybe 10-15 percent of your entire pasture grasses,” she says.

The aristida species, or threeawns – the species to which needle grass belongs – typically has three awns, or stiff bristles extending from the seedheads, making threeawns easy to identify.

All of the threeawns have grazing benefits, says Morgan.

“The key to getting away from those challenging awn issues is to graze it earlier in the year before it goes to seed,” she says. “That goes for baling, too. If you’re going to bale prairie hay, get it earlier in the year before it matures into that seed head, and you’ll avoid all of these issues entirely.”