Pasture Plants that can Harm Goats
Updated: Oct 14, 2022
We all know that goats don’t eat just anything. However, there are several plants that do pose health risks to goats. Some of these harmful plants are more common than others, and a few can be found in the pasture.
Pasture management for goats is an ongoing process.
This list of toxins and toxic plants is by no means exhaustive. Also, the goal of this article is to provide an overview understanding of the most common toxins and their effects.
Goats are Herbivores that Browse
Goats are actually classified as Browsers rather than Grazers.
Where animals like horses and cows Graze, which means they eat mostly grass and very low-to-the-ground vegetation, Browsers tend to eat vegetation that grows a little higher from the ground. Bark from trees, leaves, and shrubs are all examples of things that goats tend to prefer.
Additionally, animals who Graze have smaller mouths and stiffer lips for ripping up grass, while Browsers have wider mouths and longer tongues for reaching up and grabbing plants that are higher-up.
It makes them master brush clearers who are capable of finding lots of nutrient-dense and healthful forages. On the flip side, this also leaves them open to finding a lot of nasty stuff that can harm them.
But the attentive goat owner does not need to fear. A bit of awareness and familiarity with your region allows you to eliminate negative plants in your pastures while promoting the positive. Pasture management for goats is an ongoing process; what you get will vary according to grazing intensity, the current season, or other climate factors.
Goats have Great Instincts Towards Harmful Plants
It’s important to note that goats DO have active immune and digestive systems that can be relatively resilient to many toxins.. Many forages can be toxic to goats but it all depends on the dosage.
However, concentrated toxins can be harmful and/or deadly. Goats usually avoid eating harmful plants unless there is little else available to them, or at times - just out of curiosity when plants are first encountered.
Most toxic plants are unpalatable and are very unlikely to be eaten. Many toxins that are ingested are often diluted if other quality feed is available limiting the severity of their effects. However, toxins like Cyanides and some Alkaloids or Glycosides such as Japanese Yew and Oleander are severe and often fatal.
Anything in Excess can be Harmful
Be aware that most any field or pasture that is Over-Grazed will be more prone to invasive species. Special care should be taken in the springtime because the toxic invasive plants often sprout first before native grazing plants will abound.
This is where it’s critically important to actively work on pasture management for goats and have familiarity with your particular region and the types of toxic plants known to grow there. Unfortunately, goats can be exceptionally prone to this as they can eat bitter and abrasive forages that other animals would avoid.
Even tannins, ( while certainly beneficial ), can be poisonous when consumed in high concentrations and/or grazed extensively. Oak leaves, for example, are notoriously very high in tannins which is why grazing animals near them is not recommended.
As a rule of thumb, woodland and wet or swampy areas tend to have a higher likelihood of harboring poisonous plants.
Types of Toxic Plants for Goats
The listings available to us of the plants with a degree of toxicity to goats is Extensive — and some plant specifications require further research, as no one knows when or if the list will ever be complete.
Fellow goat breeders in your region and university extension offices can be your most Invaluable tool in narrowing down what you should look for.
You may even be able to find someone with native plant knowledge who would walk your pasture with you and advise what hay not to buy.
Cyanogenic Glycoside ( Cyanide ) – This toxin makes hemoglobin (blood) less able to deliver oxygen to tissues. Signs and symptoms often appear rapidly and include difficulty breathing, excitement, tremors, gasping, dilated pupils, bright pink mucous membranes, bloat, staggering, involuntary urination and defecation, convulsions, coma and death due to asphyxiation. Treatment for Cyanide is sodium nitrite or sodium thiosulfate however most animals die before treatment is available.
This includes stone fruits like peaches, plums, and wild cherries, which are especially toxic when leaves are wilted, and death can be sudden.
Plants with Pitted Fruits
Clovers – when fresh
Other Glycosides – There are many types of glycosides however most have similar signs and symptoms; some are less dangerous than others. Signs and symptoms include severe vomiting and diarrhea, swollen and inflamed oral tissues, cold extremities, dilated pupils, increased heart rate, weakness and death.
Oleander – extremely toxic
Alkaloid Toxins – There are many types of alkaloid toxins. Signs and symptoms include vomiting, diarrhea, bloat, weakness, nervousness, trembling, difficulty breathing, incoordination, dilated pupils, decreased heart rate, convulsions, coma and death due to cardiac standstill.
Alkaloid plants are powerful organic substances known for their physiological impacts — nicotine and morphine are a couple of famous examples. Plants in the hemlock family, nightshade, and poppies are a few examples that livestock might encounter.
Japanese Yew – extremely toxic
Stagger Grass (Fly Poison)
Yarrow (Mild Gastrointestinal Irritant)
Most of these cultivar ( food ) species have been developed to have reduced toxins and are generally safe to feed livestock.
Nitrate Toxins – Several Nitrates exist, but when nitrates are digested they breakdown to nitrites which bond with hemoglobin which blocks oxygen delivery to tissues. Signs and symptoms include tremors, increased but weak pulse, decreased temperature, weakness, staggering, difficulty breathing, discolored mucous membranes, nervousness, frequent urination, diarrhea, collapse, coma and death; surviving animals may abort. Blood of affected animals is dark red or brown. Nitrate toxicity may be treated by veterinary treatment of methylene blue.
Clovers – when fresh, dry is neutral
Oxalate Toxins – Ruminants tend to be more resistant to oxalates. Ruminants can however be affected when the majority of their grazing is made up of oxalate plants such as Greasewood. Oxalate toxins can cause swollen kidneys, bleeding in the rumen wall, and fluid in the abdominal cavity. Signs and symptoms can include weakness, depression, weak pulse, gastrointestinal paralysis, salivation, vomiting, diarrhea, difficulty breathing, coma and death.
Lactone/Helenalin Toxins – The primary culprit of this toxin is Sneezeweed. This is a mild toxin that may become severe if no other forage is available over time. Signs and symptoms include wasting, depression, profuse vomiting, salivation, stiffness, weakness, secondary pneumonia and death. No treatment exists - but animals may recover from early detection and removal from the source.
Enzyme Toxins – Enzyme toxins are somewhat unique in the sense that they destroy necessary nutrients. These toxins essentially create an abnormal nutrient deficiency of vitamins and or minerals. Thanks to the ruminant digestive system, many enzyme toxins are greatly neutralized by the production of vitamins from nitrogen in the digestive process. Some however carry carcinogens as well that cause tumors typically in the bladder.
Cicutoxin – Hemlocks. like poison hemlock and water hemlock, are most common for this toxin. The concentration of this toxin is in the roots and creates a strong carrot odor. Cicutoxins are potent and fast acting. Signs and symptoms include rapid respiration and pulse, dilated pupils, drooling, muscle tremors, convulsions and coma, culminating in a death from asphyxiation.
Toxalbumin – Black Locust is the primary toxin containing plant. Signs and symptoms of toxalbumin include lack of appetite, diarrhea, weakness, depression, founder, weak pulse, hindquarter paralysis, cold extremities, dilated pupils and colic. Death from toxalbumin is rare, no treatment exists and it is a slow recovery.
Hypericin – Hypericin is a photosensitizing toxin. meaning that it is made worse by exposure to sunlight. Unpigmented skin becomes inflamed and itchy and large areas may slough. They may also go blind, convulse and die. St. Johnswort is the primary plant.
Hypericin / Photosensitizing plants:
St. Johns wort
Gallotannin – Oaks are most well known for carrying Tannins. Tannins are most concentrated in young leaves, and green acorns. Tannins affect the kidneys and gastrointestinal system. Signs and symptoms of Gallotannin toxins include poor appetite, emaciation, constipation followed by diarrhea, frequent urination, depression, excessive thirst and death. Mild cases may be treated with calcium hydroxide. This may also be used preventatively if oaks cannot be avoided. Also, thanks to the ruminant digestive system, Goats can usually neutralize mild tannins, although high concentrations can still pose a risk.
Resin Toxins – Resin toxins make up a smaller group of toxins generally presenting with signs and symptoms including incoordination, salivation, bloat, weakness, muscle spasm, coma, and death. Animals may be found down, unable to stand, with their heads weaving from side to side. There are many various plants and toxicities as well.
Resin Toxin Plants:
Ponderosa Pine (mostly for cattle)