Pearl Snaps

Stories of a cowgirl living life by her own lights

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Weedy Wednesday: Yew


Common name:Yew, Taxus
Scientific name:Taxus species

Life Cycle: Perennial
Origin: Many countries
Poisonous: Yes, extremely

Taxus species, frequently called “yew” are used as ornamentals in much of the eastern United States and Canada. Generally, these evergreen plants are found in highly managed landscapes.Taxus plants thrive under many conditions, which make them a popular choice among gardeners and landscapers. Small and large farm owners might plant them without realizing their toxicity to horses and other livestock.

Taxus leaves, bark, wood, and seeds are poisonous to livestock, especially horses. Poisoning might occur from animals eating plants or pruned plant parts left on the ground. When large amounts are consumed, horses can succumb to death within a short time and without additional clinical signs. Thus, animals are often found close to plants they have eaten, sometimes with plant parts in their mouth. In less severe cases, typical clinical signs include trembling, labored breathing, and collapse.

Remove taxus plants from horse farms to avoid the possibility of horses eating them. Dig the plant and remove it from the farmstead.

Consult your local Cooperative Extension Service personnel for specific identification and control in your area.

William W. Witt, PhD, a researcher in the department of Plant and Soil Science at the University of Kentucky, provided this information.

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Weedy Wednesday: Plants That Kill

There are many toxic plants in the world.  Having a working knowledge of  them can sometimes be the difference between life or death in the circumstance that an animal in your care ingests such a plant.  This recent article found in on touches on several toxic plants to equines that every horse owner should be aware of.

Plants That Kill

by Pat Raia

One spring a few years ago, four horses on a Colorado farm began losing weight and developed photosensitization (a condition characterized by sensitivity to sun exposure) and neurologic signs. A thorough physical exam and blood work helped veterinarians determine the horses had extensive chronic liver disease, and a liver biopsy confirmed typical signs of pyrrolizidine alkaloid poisoning. These alkaloids are typically found in groundsels such as tansy ragwort, fiddle neck, and rattle pod. However, none of these plants were present in the horses’ pasture.

But when the horses’ owner broke open a bale from the hay supply he had been feeding all winter, he noticed significant amounts of broad, hairy leaves that were eight to 12 inches long. These leaves were identified as hound’s tongue, a noxious weed in many areas across the country that contains significant quantities of pyrrolizidine alkaloids. Hound’s tongue remains toxic even when dried in hay. These alkaloids have a cumulative effect on the liver, and after eating the contaminated hay over the winter, the horses developed chronic irreversible liver disease. Eventually, all four of the affected horses were euthanized because of liver failure.

Hound’s tongue is one of myriad plants toxic enough to cause illness and even death in horses. So it’s important that owners recognize poisonous plants growing in or near their horses’ pastures and prevent their animals from ingesting them.

According to Carey Williams, PhD, extension specialist and associate director of outreach at Rutgers University’s Equine Science Center, horses generally avoid eating poisonous plants, especially when more palatable choices are available.

“Most poisonous plants have defense mechanisms–syrup or sap that’s very bitter or spines and thorns that make them uncomfortable to chew or swallow–so horses will generally avoid them, especially if they have lots of good-quality hay and good-quality pasture available to them,” she says.

Click here to read the column in full length and learn more about plants that are toxic to horses.


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