Is Dallisgrass Good for Horses? (Be Careful About This Weed)

By Zunnun Ahmed •  Updated: 08/20/22 •  5 min read

The name Dallisgrass makes me imagine a delicate, flowery plant. 

But a total opposite…’s life-threatening!!!!

Actually, its palatability makes the horses so attracted to it that they make themselves sick eating it. Being so tempting yet sickening jerks me to wonder, is dallisgrass good for horses?

Sadly enough, this weed is not good for horses, and its poisoning results in tremors and staggering in the horses. The grass attacks the nervous system of horses, resulting in shaking, muscle weakening, and falling. This convinces me to let my horse avoid eating dallisgrass totally.

This article is all about dallisgrass, its components, pros and cons, origin, and why it’s toxic for not only horses but all livestock.

So……..What is dallisgrass?

Hailing from Uruguay and Argentina, The dallisweed is now a common bunchgrass and is quite famed due to its fast shooting up to 2 meters tall. Before knowing more about how and what it does, let’s look at its fact file. 

Let’s talk about its structure.

This grass grows in the form of loose bunches and the Grothe is 1 to 5 feet tall. The plant is erect. 

The base of the stem from where the leaf starts is flat, but the stem is hairy and inflated. The ligule (undergrowth of a leaf where it attaches to the stem) is covered with a membrane.

What is dallisgrass

Is horseweed poisonous to horses?

Yes, the horseweed is poisonous to horses, cattle, and many other animals like dogs and cats. It has alternative names: Mare’s tail, Canada fleabane, and Canadian Horseweed. 

The main problem is……..

The horseweed happens to be found in gardens, fields, roadsides, and vacant areas. The places horses like to roam around for grazing.

This weed is basically attacking the digestive tract, mouth, or skin when taken. You could find your horse with clenched jaws after eating it. The weed can irritate the nostrils of the horses. 

Fact: The weed tastes bitter, and the usually livestock don’t prefer to eat dallisgrass unless they are super hungry. 

Related: Can Horses Eat Sunflower Seeds? Explore Nutritional Benefits

What makes Dallisgrass poisonous for livestock?

The grass is influenced by a fungus similar to ergot fungus. 

This is Claviceps paspali, found at the tips of flower heads of the dallisgrass in the form of a sticky substance. 

You need to have a closer look at it. 

The fungal pathogen becomes a disease to the plant. When it is consumed by livestock, it leads to mental illness. Specifically to the horses, the problems it can cause are many:

Why don’t you feed dallisgrass to your horse?

I know it seems refreshing to see the fast-growing green weed.

But how it affects the horses would stop you from thinking positively about dallisgrass.

Here is why you may not like feeding your horse with it:

Hence, the problem is the fungus in the dallisgrass makes it a wrong choice for your horse.

Related: What happens if a horse eats corn?

How to know your horse gets poisoned? Symptoms of dallisgrass poisoning in horses

Before explaining the symptoms of the poisoning, it is considered to talk about when it affects. 

Sometimes, the symptoms may appear in the first few hours of consuming the grass or after several days. 

The truth is………It depends on how much dallisgrass is eaten by horses. 

Moreover, some horses don’t even show the slightest symptoms of poisoning. But they commonly appear to all eating the dallisgrass in the same pasture.

Symptoms include:

The symptoms must be considered as soon as they appear and come under veterinary guidance. It is because there are cases where the poisoning has led to coma and death in horses.


The weed mentioned above, dallisgrass, is not likely a good choice for your horse. The bad news is that there is no antidote for the poisoning. 

The vet would go for detoxification and liquid intake to flush out the poison from the kidneys of horses. It is better to stay away from your horse from the weed as prevention is always better than cure. 

Zunnun Ahmed

We are a group of horse enthusiasts. We want to provide information and tips to help others learn more about horses, how to care for them, and how to enjoy them.

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