Lathyrus Poisoning

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Approximately 3 years ago my daughterís new show horse, Hollywood Attitude, became extremely ill from eating Willamette Valley grown alfalfa hay that was contaminated with Lathyrus, commonly known as wild sweet peas. His nervous system was attacked by the Lathyrus toxins, which focus their attack on the hind limbs of animals or humans that eat the dried seeds. Woodys hind legs were paralyzed, his lymph nodes in his throat were hugely enlarged, and his liver was in danger of shutting down. He took a year to recover from this poisoning, and almost 2 years to be 100% cured. The farmer denied any responsibility for my horses condition. This Oregon State University agriculture graduate swears that wild sweet peas are just a form of vetch and are not poisonous. He refused to read the information that I gave him on Lathyrus poisoning from several university sites and veterinary journals. Rather than get lawyers involved, I chose to not pursue reimbursement for the approximately $5000 in vet bills that I accrued.

Lightening apparently can strike twice. Two weeks ago, my show horse became sick for a week with hives and was off his feed. After a week, I rushed him to my vet, Dr. Howard, because his legs were so swollen that his skin was splitting and fluid was running down his legs. The vet did a bunch of blood workups and there was no sign of an infection, (no high white cell count and no fever). The only thing that was elevated was his liver function numbers. The vet asked me a lot of questions about Woodys feed, was anything new? He had me take him off of grain and give him steroids and penicillin twice a day. He was better by Thursday so I put him back on grain. Friday Woody had some hives and was swelling again. Saturday his legs were swelling all of the way down again, he wasínt eating or drinking, and the lymph nodes in his throughtlatch area were very swollen. I rushed him back to the vet. Again, he questioned me about feed, but I said nothing was different. He gave me some very strong steroids and long-acting antibiotics and told me to take him off of the pasture and grain again.

When I got home I went into sleuth mode and began sifting through both types of hay that I feed, and all of the bags of oats, cob, rice bran, vitamins, etc. I smelled and tasted everything. It was all fine. Luckily, it was a sunny day and I had left the barn door open. As I was pouring a large scoop of rolled oats into the horses buckets, I caught a glimpse of a black seed in the oats. I ran outside with the bucket, and there was the answer. The rolled oats were not the usual triple cleaned that I buy. The bag was filled with all sorts of chaff and approximately 5% of the grain volume was Lathyrus seed. Wild sweet peas strike again!

I canít believe that farmers and distributors donít realize that this common weed that grows throughout the United States is highly toxic to birds and mammals in the dried seed form. If I had not been through this horrible experience once before with contaminated alfalfa hay, I would not have recognized the small black peas and would have continued to feed and poison my horse. Show season is only 2 weeks away and I wonít be able to clear all of the toxins out of Woodys system by then, but hopefully he can at least go.

Please forward this warning to anyone who has horses anywhere in the United States. The beautiful bright pink wild sweet peas that you see growing along the roadside are extremely poisonous to horses in the dried seed form, (the green form of the plant is a nutritious legume that some farmers actually encourage to grow). Please check your hay for small 1 ĹĒ pods with 1/8Ē black or dark brown peas. Please check any sacks of grain for these small dark peas.

Here are some websites that have pictures of Lathyrus: ¬ The University of Pennsylvanias Poisonous Plants. Click on plants by Latin name and click on Lathyrus.  The Canadian Poisonous Plants Information System Click on poisonous plants by Botanical name, then on Lathyrus