Oleander along the Woodside trails
Date: March 29, 2012
Good evening. I thought contacting you would be a good start in getting the word out to our local trail users and remind them of the potentially serious affects of oleander ingestion by a horse. A recent case which ended in the loss of the horse prompts me to want to remind all horse owners that use the public trails in Woodside. In this particular instance, the owner was hand walking a horse that was new to the area. Without recognizing at the moment exactly what happened, a day later the horse became quite ill and subsequently died despite intensive medical care. A necropsy by the state lab in Davis confirmed the damage to the heart and other organs as well as isolation of the toxin in the horse's system, leaving little doubt of the correct diagnosis. In hindsight the owner's recalled the horse nipping at some bushes and was able to return to the exact location and identify the plant. I visited the site with the owners and agreed that a substantial portion of the trail along Canada Rd. has oleander mixed in with bottle brush, bay, oak and other bushes. To the unwatchfull eye it would be very easy to miss.
Most people I talk to, including several other veterinarians in this area, all agree that most horses will avoid eating toxic plants including oleander. Most poisoning occurs accidentally when oleander leaves find their way in to lawn clipping that are then fed to the horse. Like myself, the other veterinarians in the area had never encountered a case similar to this. That's why I felt it important to get the word out as a reminder to us all that there are few absolutes when it comes to animals so it's important that we all be vigilant of hazards like this.
I'm not familiar with the Town of Woodside's policy in establishing and maintaining a safe trail system. I also do not know if there are any ordinances in place to regulate the types of plants placed along the trails. I think it's unreasonable to expect the removal of all poisonous plants along the trail so the burden falls back to the owner/rider to take appropriate action in advance.
I hope you can use this information in a positive way and with your resources and connections help inform other horse owners. If you have any specific questions please feel free to get in touch with me.
Gary E. Hanes, D.V.M.
Briarwood Equine Clinic
2995 Woodside Rd. Suite 400
Woodside, CA 94062