06/17/2026
https://www.facebook.com/share/p/1EQe9gwSuC/
๐๐ก๐ ๐๐ง๐๐ฑ๐ฉ๐๐๐ญ๐๐ ๐๐๐ฎ๐ฌ๐ ๐จ๐ ๐ญ๐ก๐ ๐๐๐ง๐ญ๐ซ๐๐ฅ ๐๐๐ซ๐ค ๐๐๐ซ๐ซ๐ข๐๐ ๐ ๐๐จ๐ซ๐ฌ๐'๐ฌ ๐๐๐๐ญ๐ก: ๐๐๐ฉ๐๐ง๐๐ฌ๐ ๐๐๐ฐ
In my previous posts, I discussed how horses can sometimes collapse suddenly and how important it is to avoid jumping to conclusions before a necropsy is completed.
According to reports, the necropsy on the Central Park carriage horse identified Japanese yew poisoning as the cause of death. If confirmed, this tragedy serves as an important reminder that some of the greatest dangers to horses are not always what people expect. Sudden death is not always the result of overwork, heat, age, or pre-existing disease. Sometimes it can be caused by exposure to an extremely toxic plant.
๐ฒ ๐๐ก๐๐ญ ๐ข๐ฌ ๐๐๐ฉ๐๐ง๐๐ฌ๐ ๐ฒ๐๐ฐ?
Japanese yew (Taxus cuspidata) is a common ornamental evergreen shrub used in landscaping throughout North America. Many people have seen it in residential yards, parks, businesses, and around public buildings without realizing it poses a serious risk to horses and other livestock.
The mature height depends on the specific cultivar and how it is maintained but heights in their natural habitat of Northeast Asia have been recorded as tall as 50 feet while those used in landscaping reach 10 to 30 feet on average.
โ ๏ธ ๐๐ก๐ฒ ๐ข๐ฌ ๐ข๐ญ ๐ฌ๐จ ๐๐๐ง๐ ๐๐ซ๐จ๐ฎ๐ฌ?
The plant contains compounds called taxine alkaloids, which affect the heart's electrical system. The taxine alkaloids in Japenese yew are rapidly absorbed and interfere with the normal function of the heart, acting as a cardiac depressant. The interference can cause severe arrhythmia and circulatory collapse which can lead to sudden cardiac arrest.
All parts of the plant, both fresh or dried, are toxic, except the fleshy part of the aril surrounding the seed. Ingesting as little as 0.1% bodyweight, or about 0.5 to 1 lb, can be lethal to horses.
โ ๏ธ ๐๐ก๐๐ญ ๐๐จ๐๐ฌ ๐ฉ๐จ๐ข๐ฌ๐จ๐ง๐ข๐ง๐ ๐ฅ๐จ๐จ๐ค ๐ฅ๐ข๐ค๐?
One of the most frightening aspects of Japanese yew poisoning is that there may be little to no warning. The most common clinical sign is sudden death often occurring within 20 to 30 minutes of ingestion.
However, if clinical signs are observed, they may not occur for up to 12 hours after eating any plant material and can include:
โข Gastrointestinal upset (colic)
โข Difficulty breathing
โข Tremors or muscle weakness
โข Loss of coordination
โข Slow heart rate
โข Collapse
๐ฉบ ๐๐จ๐ฐ ๐ข๐ฌ ๐ข๐ญ ๐ญ๐ซ๐๐๐ญ๐๐?
Due to the rate of progression of the disease, treatment is often not possible and survival is rare as the toxins interfere with cardiac cells and electrical condition rapidly.
As a result, prevention is the best route.
โญ๏ธ ๐๐จ๐ฐ ๐๐จ ๐ก๐จ๐ซ๐ฌ๐๐ฌ ๐ ๐๐ญ ๐๐ฑ๐ฉ๐จ๐ฌ๐๐?
Most poisonings occur when:
โข Landscaping clippings are tossed into or near a pasture
โข Storm damage drops branches into turnout areas
โข Horses gain access to ornamental plantings
โข Well-meaning neighbors dispose of yard waste where livestock can reach it
However, many horses wonโt eat this shrub due to the bitter taste unless there is limited forage available.
๐ ๐๐ก๐ ๐๐ข๐ ๐ ๐๐ซ ๐๐๐ฌ๐ฌ๐จ๐ง
This case highlights why investigations and necropsies matter.
At the same time, it is a good reminder to take a closer look at the plants growing around our farms, barns, and neighborhoods. Sometimes the greatest threats to our horses are hiding in plain sight.
My heart goes out to everyone affected by this loss. No matter where someone stands on the carriage horse debate, the death of a horse is a tragedy, and hopefully this case can also serve as an opportunity for education and prevention.
Dr. DeBoer
