Is Blue Fescue Grass Poisonous to Cats?

Cat owners know that their frisky felines can and will get into trouble from time to time, including eating plants that they shouldn't. Blue fescue (Festuca glauca), which thrives in U.S. Department of Agriculture zones 4 through 8, is an ornamental grass prized for its delicate blue-green foliage. The fine texture of the leaves and its tendency to form thick clumps makes this decorative plant attractive to gardeners and cats alike.

Although fescue poisoning is well known to livestock caregivers, blue fescue does not pose the same risk to cats. The fescue poisoning known in horses, sheep and cattle is caused by a fungal infection of a different type of fescue grass (tall fescue, or Festuca arundinacea). Seeds infected with the Acremonium coenophialum fungus produce grass infected with the same and can cause weight loss, fever, rough coat, tissue death and difficulty during labor in pregnant animals. Blue fescue does not harbor the same toxins, nor does it contain any substances toxic to felines when ingested.

According to the University of California Cooperative Extension, contact dermatitis is a risk to cats who romp in blue fescue. Contact with the sap of blue fescue puts cats at a higher risk for this ailment. Contact dermatitis, or an irritation of the skin, presents as red bumps and inflamed skin, accompanied by moderate to severe itching. Because cats have a thick coat of hair and fastidious grooming habits, dermatitis from contact with fescue grass is unusual.

No one knows exactly why cats ingest grass, with theories ranging from folic acid supplementation to cats using it instinctively as a laxative or fiber supplement. Although blue fescue is nontoxic for cats, stomach upset can occur after ingestion. Cats lack the necessary enzymes to digest grass. Because they are unable to process it, it’s usually regurgitated. While seeing your cat vomit is alarming, it’s perfectly normal after eating grass.

If your cat develops a rash or skin irritation after contact with blue fescue grass, wash the area with soap and water. If the rash is severe or your cat exhibits signs of pain, consult a licensed veterinary medical professional. In some cases, contact dermatitis leads to traumatic self-injury. The cat licks the area because it itches, which causes more itching that leads to more licking, and eventually open sores develop. Open sores can become infected and necessitate the use of antibiotics to stop the infection and antihistamines to reduce the itching and self-injury.