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Healthy Pastures, Healthy Horses Keeping our horses safe and healthy: the prevention of plant toxicity through good pasture management This is the largest database of its kind.

The promotion of good pasture health has far-reaching impacts, including reducing the presence of toxic plants and invasive weeds. Just as our own diets create disease and disorder within our bodies, the diets of equines do the same for theirs. Yet far too often, equines (horses of all sizes and breeds, donkeys, mules, and ponies) graze in unhealthy pastures. The consequences of toxic plants and w

eeds in pastures are many, and can be very severe. For instance: one mouthful of some ornamental shrubs can kill a horse within hours...eating a certain prickly weed can create a deadly addiction...the wilted leaves of some shade and fruit trees can kill your horse...some toxins persist for years even when dried in hay…many invasive and noxious weeds are highly toxic in amounts as little as eight ounces...and it can take months or years of ingesting some toxic plants and weeds before clinical signs even appear, at which time it may be too late for treatment. Years of graduate research and study have resulted in our database of several hundred plants that cause toxicity in equines. The effects of many of these plants can be fatal, sometimes very swiftly. Even if toxic events do not result in death, most result in high financial cost. Good vet care is expensive; tests and treatments can be outrageously high priced, and there’s no guarantee of success. Euthanasia and burials are pricey...and then there are the emotional costs. The anguish when your horse is ill or hurting...or the pain of losing it...is excruciating. Knowing that it was preventable through awareness on your part is heartbreaking. Being proactive is a must. We cannot adopt a wait-and-see attitude where the issues of equine and pasture health are concerned. It is possible to greatly reduce, if not nearly eliminate, plant toxicity through proper pasture management and diligence. Good pasture management techniques also significantly increase forage production and reduce feed/hay costs, prolong the grazing season, decrease the presence of weeds and unwanted plants, improve soil condition, help keep the watershed healthy, benefit wildlife and your neighbors, and create a sustainable system. The purpose of this page and these materials is to educate and inform about good equine pasture management, plant toxicity, toxic invasive weeds, and grazing issues. Equines have been our champions for centuries; now it is up to us to be theirs. Thank you, for their sake, for your interest and support. One way of supporting our work and writing is through Buy Me A Coffee. We welcome and appreciate a few horse cookies now and then. :)
https://www.buymeacoffee.com/EtoE

13/07/2025
~ Hot, dry weather and pastues ~Hey all: many of us are in the throes of hot temps and dry weather. Here are a few remin...
12/07/2025

~ Hot, dry weather and pastues ~

Hey all: many of us are in the throes of hot temps and dry weather. Here are a few reminders to help equines and pastures through these periods:

Plentiful cool, clean water is our best defense against not only heat-related ailments, but particularly plant toxicity. It dilutes toxins and helps toxic plant material move through the gut more quickly. It also helps to prevent impaction.

Watch for new populations of invasives and potentially toxic plants. Of particular concern are areas around water sources, manure piles, bathroom spots, fencelines, and shaded spots.

Look for down/wilting trees/branches, especially those of the cherry/plum family (Prunus spp.), oaks (Quercus spp.) and the maple/boxelder family (Acer spp.). These can be particularly toxic when stressed by breakage or hot weather.

Hungry horses are horses at risk. They tend to sample plants they ordinarily would find unpalatable just to fill their bellies. If forage heights are 3" or less, move animals and provide supplemental hay.

Remember that heat-stressed, depleted pastures can undergo substantial damage that lasts for years. As above, if average forage height is 3" or under, move horses to another pasture or if that's not possible, feed hay to help prevent soil compaction and grass mortality.

Bored animals are also at risk. When they're bored, they nibble at anything. Be sure to know the plants in all loafing areas. If there are toxic plants, remove them or exclude animals from that area until plants are gone.

Remember that some plants are able to continue to set seed after pulling or cutting, so all plant material should be disposed of in bags in garbage bins. If removal isn't possible now, at least cut flower heads and put them in grocery/garbage bags for disposal.

Watch animals for signs of phytophotodermatitis (photosensitivity). Whether primary (from a toxin directly) or secondary (from liver disease caused by hepatotoxins), if we see sunburn-like clinical signs, the cause needs to be addressed. Move animals to a shaded area with plenty of good water and hay, and call the vet to be safe. Mild cases can be treated with OTC ointments but we should never assume it's 'just a sunburn'.

Weeds and native plants, just like forage grasses, can be higher in sugars in hot weather. Even if they're not toxic, ingestion of them can have negative consequences for our IR, EMS, and Cushing's animals.

There's no reason for anxiety or alarm, but during weather events we need to be especially aware of potential dangers. It only takes a few minutes each morning to inspect animals, water tanks, and lounging areas. Fenceline inspections can be a good reason for a twilight ride when it cools (if it cools!).

Be vigilant and keep 'em safe!

Some good info about horsetails and scouring rushes (Equisetum spp.) including recommendations for control.
12/07/2025

Some good info about horsetails and scouring rushes (Equisetum spp.) including recommendations for control.

Horsetail, scouring rush and many other Equisetum species are Pacific Northwest natives. They grow throughout the region. Plants live for many years and are often found in wet or seasonally wet areas. The most common species are field horsetail (Equisetum arvense), giant horsetail (E. telmateia), an...

~ How and why are plants toxic? Part 2 ~Chemical defenses, or toxins, are generally not needed for everyday growth or re...
11/07/2025

~ How and why are plants toxic? Part 2 ~

Chemical defenses, or toxins, are generally not needed for everyday growth or reproduction of plants. They do, however, have a role to play in defending the plant against damage by herbivores.

A great deal of research has been done on plants' chemical responses to herbivores of all sorts, from insects to large mammals. At times, our grazing animals are the unsuspecting victims of plant chemicals evolved for another herbivore entirely, such as an insect. Plants that evolve with certain insects develop chemical defenses against them, and some of these are also highly toxic to grazing animals. Plants are even known to be responsive to touch, and some are able to not only change their growth forms as a result, but also to maintain higher levels of chemical defenses.

This tendency to produce more chemical toxins in response to being grazed may present dangers to our equines. If toxic plants are permitted to grow in pastures, there is the possibility that while the first few mouthfuls may not contain significant amounts of toxins, if the plants are revisited, their chemical defenses may be higher. The more the plant community is under attack, the higher their defenses may be, because at that point, survival is more important than root growth or the production of blossoms.

Many plants don't have these modes of defense, fortunately. Some simply produce more plant material or put their energy into reproduction. However, some toxic plants and w**ds, particularly as the grazing season progresses, can respond defensively to being grazed repeatedly. Some of these defenses may be dangerous for our equines.

Our first line of defense against toxic events is in being proactive by (1) knowing the plants in our pastures and (2) managing pastures for plentiful healthy forage so that unwanted plants aren't a temptation. Let's keep 'em safe and healthy!

Sad post...We were going to have a FrIDay toxic plant and w**d ID quiz but are having Mac issues.So we'll have to put th...
11/07/2025

Sad post...

We were going to have a FrIDay toxic plant and w**d ID quiz but are having Mac issues.

So we'll have to put that off until next week.

Cross fingers!

~ How and why are plants toxic? Part 1 ~The number of plants toxic to our horses (ponies, donkeys, mules) sometimes seem...
10/07/2025

~ How and why are plants toxic? Part 1 ~

The number of plants toxic to our horses (ponies, donkeys, mules) sometimes seems staggering. And it kind of is: our database, which is the largest we know of in existence, has well over 400 species with some type of toxicity to equines.

According to comments we've received from stewards, toxicity can feel as if it's deliberate, as if plants actually have an agenda of hurting our animals. They don't, of course, at least not directly.

Let's take a closer look at why and how plants are toxic.

Herbivores (equines, in our case) select plants for palatability, nutrition, and sometimes ease of ingesting. Plant defenses against this are usually not extreme, as most plants have some tolerance to herbivory and the ability to heal wounds. However, in more extreme cases (as in severe grazing pressure), some plants are able to increase their defenses.

Some of these defenses may also include those that first make the plant unpalatable. They come at relatively little cost to the plant, and may either make plant material tough and hard to chew or digest, or they may produce flavors or odors that are unpleasant.

Physical structures like spines or large numbers of thorns that decrease or prevent herbivory have a somewhat higher cost to plants, as energy and nutrition must be directed toward creating these structures. However, since these structures don't continue growing past a certain stage of efficacy, their cost to plants is temporary.

The production of high amounts of chemical toxins is usually at the highest cost to other areas or processes, such as growth of roots or foliage or the production of blossoms and seeds. For that reason, plants often don't produce huge levels of these defenses on a constant basis, as they're expensive for the plant to maintain.

This is the reason we see toxicity in stressed plants such as Prunus (cherry family) spp. or Sorghum (sorghum family) species, among others. When the plant is under physical stress, it can't afford to lose foliage, so it produces defenses against damage. This is true of entire plant communities, not just single plants. At other times, toxicity levels are much lower.

Part 2 later this week...

~ It's WeedsDay ~In mid-late summer we tend to see a lot of unwanted plants popping up in pastures. The term 'unwanted' ...
09/07/2025

~ It's WeedsDay ~

In mid-late summer we tend to see a lot of unwanted plants popping up in pastures. The term 'unwanted' couldn't be more true for members of the potato/tomato family (Solanaceae).

Many members of this family are toxic, possibly deadly so. The toxic threshold can range from a few ounces to a few pounds of plant matter. Toxicity varies between fruits and foliage; with some species the fruits are more toxic, and with others, less so. The green fruits are generally highest in toxins, however.

The toxins are glycoalkaloid or tropane alkaloids; solanine is the most common one. Saponins are also found in many family members. Many nightshades are also nitrate accumulators.

Clinical signs usually initially center around the gut with diarrhea and colic, but also may include appetite loss, lack of coordination, staggers, mouth/gum irritation, excessive thirst, vision issues, agitation, cardiac irregularities, hypersalivation, excessive urination, increased or decreased heart rate, odd behavior, convulsions, tremors, dilated pupils, depression, collapse, and death.

This list is by no means comprehensive, but it contains some of the common species that are fairly widespread.

Deadly nightshade (Atropa belladonna)
Buffalobur, buffalo burr nightshade (Solanum rostratum)
Climbing nightshade, bitter nightshade, day jessamine (Cestrum diurnum)
European bittersweet, woody nightshade (S. dulcamara)
Cutleaf nightshade (S. triflorum)
Black nightshade (S. nigrum)
Bull nettle, horse nettle (S. carolinense)
Silverleaf nightshade (S. eleagnifolium)
Jerusalem cherry )S. pseudocapsicum)
Hairy nightshade (S. sarrachoides)
Common nightshade (S. americanum)
Jimsonw**d (Datura stramonium)
Western horsenettle (S. dimidiatum)

These aren't w**ds but are found in our gardens:

Potato (S. tuberosum et al)
Tomato (S. lycopersicum et al)
Ground cherry (Physalis pruinosa)
Tomatillo (Physalis ixocarpa et al)

While it's important to keep our equines away from the garden members of this family, some of their country cousins pose as much if not more dangers. Most of these plants are also toxic to other animals, including humans, so none of them (except the garden species) are plants we want on our properties.

This is a time of year to be especially vigilant about toxic plants. Those weekly pasture walks are a must now with forage quantity and quality decreasing. Let's keep 'em safe!

~ It's Toxo Tuesday ~Not all toxic w**ds are ones that equine stewards notice in pastures. Some common ones are overlook...
08/07/2025

~ It's Toxo Tuesday ~

Not all toxic w**ds are ones that equine stewards notice in pastures. Some common ones are overlooked due to their small size and innocent appearance. One group of these is the Oxalis genus.

Numerous Oxalis species are toxic, and toxicity varies between them. Most severe toxic events occur with the ingestion of large amounts, but smaller amounts can cause illness as well. Toxicity can be either acute (large amounts in short periods of time) or chronic (smaller amounts over long periods of time).

They are regionally known as oxalis, sorrel, wood sorrel (or woodsorrel, yellow wood sorrel, or wood-sorrel), soursob, sourgrass, yellow sorrel, lemon clover, shamrock, or good luck plant. They're often confused with clovers because of the similar leaves with 3 leaflets, though Oxalis have blossoms with 5 petals and heart-shaped leaflets.

They contain oxalic acid or calcium oxalates, a compound that creates a severe calcium deficiency that can result in a blood clotting disorder.

Some clinical signs include: staggers, weakness, colic, neurological issues, kidney disorders including failure, unthriftiness, enlarged heads, decreased bone density and increased fractures, muscle tremors, hyperparathyroidism, collapse, and death.

Treatment normally consists of removal from forage containing Oxalis spp. and calcium supplementation. Success of treatment depends on the levels of toxicity and damage.

These are species that many equines find palatable but likely don't normally graze on when good grasses are present. They do, however, remain green longer than grasses. During times of the year when forage is low they can present a danger.

If Oxalis spp. are part of our pastures in significant amounts, it may be time to look at control options. They can be persistent and difficult to control, and often require multiple treatments. As always, vigilance and being proactive are our best tools in keeping animals safe.

This week's issue of our E2E Info-letter Healthy Pastures, Healthy Horses is now ready for subscribers to enjoy. :) Info...
05/07/2025

This week's issue of our E2E Info-letter Healthy Pastures, Healthy Horses is now ready for subscribers to enjoy. :)

Info-letter subscriptions are how we're able to continue to donate a thousand plus hours a year to keeping your equines safe and your pastures healthy.

This week we explore: What exactly is prescribed grazing? ~ Zoopharmacognosy ~ The seven deadly sins of horse hay ~ Heart rate and variability in athletic horses ~ The benefits of fiber in forage ~ Horse pasture 'roughs' ~ A quick recap of a hay analysis ~ Taking a look at soy in equine diets ~ Free radicals and antioxidants in the equine diet ~ The improper use of mowing in pastures ~ The benefits of slow feed hay nets and their impact on equine health ~ Root health for resilience during drought ~

Subscriptions are available monthly ($5.00, 4-5 issues) or yearly ($50.00, 52 issues). You can also order a sample issue for $1.00. The topics we include aren't covered in our FB posts, so you won't see the material repeated here. See the pinned post above for info on how to subscribe (Buy Me a Coffee, PayPal, Zelle, Venmo). We work hard and long to ensure that you get your money's worth. :)

The info-letters contain three pages of informative, original, easy-to read content for all equine stewards. An entire month of issues costs less than a stop at a coffee stand, so treat yourself or someone you care about, support the work we do, and keep your equines safe and your pastures healthy!

We'd like to thank our loyal subscribers for their support and also for their very kind words of appreciation. Those mean a lot and we're always gratified that folks are enjoying our efforts and knowledge!

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The promotion of good pasture health has far-reaching impacts, including reducing the presence of toxic plants and w**ds. Just as our own diets create disease and disorder within our bodies, the diets of equines do the same for theirs. Yet far too often, equines (horses of all sizes and breeds, donkeys, mules, and ponies) graze in less-than-healthy pastures. The consequences of toxic plants and w**ds in pastures are many, and can be very severe. For instance: one mouthful of some ornamental shrubs can kill a horse within hours...eating a certain prickly w**d can create a deadly addiction...the wilted leaves of some shade and fruit trees can kill your horse...some toxins persist for years even when dried in hay…many invasive and noxious w**ds are highly toxic in amounts as little as eight ounces...and it can take months or years of ingesting some toxic plants and w**ds before symptoms even appear, at which time it may be too late for treatment. During years of graduate research and since, I have compiled a database of hundreds of plants that cause toxicity in equines. The effects of many can be fatal, sometimes very swiftly. Even if toxic events do not result in death, most result in high financial cost. Good vet care is expensive; tests and treatments can be outrageously high priced, and there’s no guarantee of success. Euthanasia and burials are pricey...and then there are emotional costs. The anguish when your horse is ill or hurting...or the pain of losing it...is excruciating. Knowing that it was preventable through awareness on your part is heartbreaking. Being proactive is a must. We cannot adopt a wait-and-see attitude where the issues of equine and pasture health are concerned. It is possible to greatly reduce, if not nearly eliminate, plant toxicity through proper pasture management and diligence. Good pasture management techniques also significantly increase forage production and reduce feed/hay costs, decrease the presence of w**ds and unwanted plants, improve soil condition, help keep the watershed healthy, benefit wildlife and your neighbors, and create a sustainable system. The purpose of this page and these materials is to educate and inform about good equine pasture management, plant toxicity, toxic invasive w**ds, and grazing issues. Equines have been our champions for centuries; now it is up to us to be theirs. Thank you, for their sake, for your interest and support.