04/18/2025
I want to share some VERY important information with everyone so please read and share.
The topic?
LOCOWEED & LOCOWEED POISONING
I have recently heard quite a few "knowledgeable" people say that locow**d poisoning is an old wives tale. That a "Locoed" horses don't exist, it is simply an excuse for a hard to manage horse.
Well I am here to say that myself, and every veterinary program in existence, can confirm it happens. CSU had a wonderful specialist in Dr. Knight who consulted on a case we had of several horses who had been poisoned. It is far different than other poisonings in that the horses don't necessarily die, or even show extreme physical signs in most cases. To understand loco w**d, one must know how it works. First, it is the Swainsonine that is the toxin, and every part of the plant contains measurable amounts. Loco is a bit like the cockroach of the plant world too. To kill the plant, it must be dug up past the crown of the roots. It's seeds are fertile for up to FIFTY YEARS, fire doesn't kill it. Most w**d sprays will only kill that year's growth. It is often one of the first real greens at the start of spring, and it has 300 varieties(only 20 are poisonous, but it can take a specialist to identify the differences AND the plant loves to accumulate Selenium, which is itself a big issue for horses), found all over the Western US. It is even dangerous dry, in hay. Another myth I hear is that horses wont eat it, and it isn't palatable. Well, if there are other good forages, and the horse isn't hungry, and it hasn't been taught to eat it by a herdmate or it's mother, it is unlikely a horse will eat it. But a lot more horses have eaten it than people want to know about, and while it does effect cattle, horses show the greatest range of symptoms are the the most effected of all sensitive species. Swainsonine disrupts normal cellular function, and it can be found in great concentrations in the BRAIN. The poisoning is NOT REVERSEABLE. A horse poisoned must be euthanized. It can be found in reproductive organs and other body fluids, so it can be passed to young. There is no treatment, and no cure, and the horse will never get better, or even improve. The neurological damage is forever. Horses can become "addicted" or develop a taste for the plant, and one horse eating it can convince others to do the same. The only safe pasture for a horse is one free of locow**d. Of all poisonous plants, horses seem to prefer loco to most. So what are the symptoms? Well, they are numerous, and can vary from horse to horse, and can depend upon the level of damage that has been done to the body
PHYSICAL SYMPTOMS
Horse may appear dull, lifeless
Coat may be dull and hard
Horse may stand with head low, eyes droopy when not stimulated
Horse may appear "sedate"
When transported, they often ride with their legs apart and their heads down, and their balance can become an issue
They may stumble, or "high step" showing lack of coordination
They may appear "drawn up"
Horse may show weight loss-though in my experience, this is not always clear unless the horse has had long term exposure
Lack of coordination
Horses often will refuse to step up, or down, may be difficult or impossible to load
Some horses may drool
Stallions may become infertile, mares may abort late term
BEHAVIORAL SYMPTOMS
One of the biggest tell tale signs, is the horse showing extreme adversity to poll pressure, they will often run backwards with no regard for anything. Many will flip over backwards as well.
They may appear to be uninterested in anything going on around them, and may not respond to stimulus like pinching, pokes, prodding, slapping (This is in horses who are gentle, unhandled horses will appear to be extremely agitated)
They may show erratic behavior, and can become violent or dangerous (even previously very gentle horses)
They cannot be tied, and will fight the pressure of being tied to the point of injury or death
Horses can react to restraint with extreme violence, stocks, hobbles, etc
Please remember, that with the exception of testing after suspected acute poisoning (with ingestion no more than 48 hours ago), there is no real "test" to confirm locow**d poisoning. The behavioral and physical symptoms are the best guide. These horses cannot be desensitized, they literally have brain damage, and they will never be their old selves again. They must be euthanized for safety of all people around and involved. They can be nearly unresponsive one second and rearing and flipping violently the next. Google it, this stuff is nasty and it is still a very real problem. Look up the pictures, get familiar with the plant. We have only had a handful of horses brought to us that were locoed but we have had to deal with a fairly advanced case even recently. The horse lived on pasture and had little interaction with people so the novice owners never saw any issues. One of the other locoed horses was brought to us as a feedlot purchase that was "extremely reactive" and the owners were afraid of it. Because it had strangles and was not halter broke no one ever connected any of the dots. I have attached the pictures of the type I have seen most often around here, and around most of Colorado. Flowers can be white and purple in various shades. Contact the CSU extension office if you need assistance in identifying it.
CHRN is a 501(c)3 non profit organization dedicated to helping at risk equines and those in danger of slaughter.
