BATON ROUGE, La. (AP) — State and federal officials are warning horse owners not to feed their animals Top of the Rockies brand alfalfa cubes after nearly 100 horses developed neurologic illnesses — 45 of which have died or been euthanized.

The U.S. Food and Drug Administration issued the warning Saturday. The agency said it’s working with state agriculture departments in Colorado, Louisiana, New Mexico and Texas to investigate the horse deaths.

Manzanola Feeds of Manzanola, Colorado, recalled the cubes Friday. The company warns that certain batches may contain bacteria that cause botulism, a fatal paralytic disease. The FDA said more testing is ongoing to confirm the causes of reported illnesses.

The company directly distributed products to stores in 10 states including Arkansas, Colorado, Illinois, Kansas, Louisiana, Missouri, New Mexico, Oklahoma, Texas and Wisconsin. The FDA warns the cubes may have been sold in other states as well.

Symptoms include dizziness, trouble with vocalizing or swallowing, difficulty breathing, muscle weakness, abdominal distension and constipation. Anyone who fed the cubes to horses or observes symptoms should immediately contact a veterinarian.

Some cubes have been reported to contain what appears to be fur and animal tissues, which may have been ground up during alfalfa harvesting. Botulism-causing bacteria is found in decaying animal carcasses.

Top of the Rockies alfalfa cubes are sold in white and tan plastic 50-pound bags with green labeling. The date codes are on the front of the package. Potentially contaminated lots include those with the date codes 111222, 111322, 111422, 111522, and 111622.

The FDA advises anyone with the cubes to throw them away in a secure container. People should wear gloves and a face mask when emptying containers with the cubes, then apply bleach solution to any feed bins or containers. More specific tips on disposal can be found here.

The Louisiana State University School of Veterinary Medicine said its lab has conducted necropsies on 12 horses. Testing of some alfalfa cubes and tissues from those horses is being done at the University of California, Davis School of Veterinary Medicine.

LSU says an equine medicine professor is treating other horses with symptoms.