2 More Horses Dead; Outbreak Believed Ending

Two more horses have died as a result of an illness believed linked to botulism in their feeding cubes, but a veterinary expert said Thursday that he still hopes that the outbreak, which has now killed at least 20 horses, is coming to an end.

One of the horses died Wednesday at a stable in Chino. Another, at the Coto de Caza Equestrian Center, was put to sleep after it became apparent that it would not recover, said Dr. John W. Byrd, the veterinarian who treated the animal.

“The horse was down and unable to stand,” Byrd said. “He was too weak to get up. . . . It looked just like the rest of the horses that we’ve seen.”

At least 20 horses throughout Southern California have died from a toxin officials believe was contained in hay cubes manufactured in Utah and shipped late last month to at least 60 stables from Ventura to San Diego.

Paramount Cubing, a Los Angeles firm that produces the horse feed, has denied that its product is responsible, but state officials have issued a recall of more than 850 tons of the feed. Byrd said in previous outbreaks of the botulism illness, horses have shown symptoms up to 17 days after ingesting the toxin.

The horse put to sleep in Coto de Caza had not been fed the Paramount cubes since Nov. 7, Byrd said. By the time he was treated, however, he was too ill to be helped by an experimental serum that has proved successful in other cases of the illness.

Three horses at the Orange County Fairgrounds in Costa Mesa that were treated with the serum earlier this month are recovering nicely, an official there said Thursday.