Poisoned Saddlebred Horses on the Mend

An American Saddlebred show horse in critical condition after ingesting unknown quantities of oleander leaves is recovering and will be released from the hospital later this week, according to the veterinarian supervising its treatment.

"He's looking brighter and turning the corner," said Steven V. Colburn, DVM, of the Creekside Veterinary Service hospital where the horse is under treatment.

The horse is among 23 Saddlebreds--including two pregnant mares--sickened after someone placed a mixture of oleander leaves and carrot and apple bits in their stalls and in an outdoor corral at Rockridge Farm in Rancho Santa Fe, Calif., last Thursday.

Three of the horses were taken to the hospital after the incident. Two were released earlier this week. The remainder were treated at the farm, said Colburn.

Oleander (Nerium oleander) is a leafy, flowering, drought-resistant plant used in ornamental landscaping in California, Utah, Arizona, and Texas. It contains cardiac glycosides that can cause colic in horses, loss of coordination, profuse sweating, difficulty breathing, abnormal heart function, muscle tremors, and potentially death from cardiac failure. As little as one ounce can be fatal to some horses.

All the horses were immediately treated with mineral oil and activated charcoal at the scene, Colburn said.

The hospitalized horses received fluids intravenously to maintain hydration and promote gut motility, and they were given intravenous doses of lidocaine to stabilize their heart rates.

On Monday blood tests revealed that all the horses' muscle enzymes had returned to normal range.

Horses generally avoid the bitter-tasting oleander unless no other palatable forage is available. Though it is impossible to determine how much oleander each horse consumed, the pregnant mares probably ingested the least because they had free-choice access to hay in their corral, Colburn said. Whether they ingested enough of the plant to harm their fetuses is uncertain.

"We don't think they got enough of it to pass through the placenta barrier, but we'll have to wait and see," he said.

Colburn treats a few cases of oleander exposure annually when horses accidentally ingest clippings after ornamental plants near grazing areas are trimmed. However, the exposure in the Saddlebreds' case appears intentional, he said.

"The leaves were mixed with carrots and apples to disguise the taste. Whoever did this knew exactly what he was doing," Colburn said.

San Diego County Sheriff's Department is investigating the incident.

In the meantime, farm owners Debbie and Tom Tomin are offering a $10,000 reward for information leading to the arrest of whoever is responsible for the poisonings. The Humane Society of the United States is also offering a $2,500 for information pertinent to the case.

"We're hoping the reward is enough to get someone to talk if whoever did this is bold enough to brag about it," Debbie Tomin said.

About the Author

Pat Raia

Pat Raia is a veteran journalist who enjoys covering equine welfare, industry, and news. In her spare time, she enjoys riding her Tennessee Walking Horse, Sonny.

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