Whinny’s Wisdom: A Field Mouse’s Perspective on Horse-Killing Weeds

Hey there, fellow creatures of the field! Whinny here, a curious little field mouse with a nose for adventure (and sometimes, trouble). Today, I want to talk about something important for any horse that gets turnout: poisonous plants!

You see, us field mice have a pretty good idea of what’s safe and what’s not safe to nibble on. But horses, with their big noses, curious ways, and knack for self-harm, can sometimes get into trouble with plants that look harmless but are actually quite poisonous. So, I’m here to share some of the most common culprits in North America, straight from the perspective of a tiny, knowledgeable rodent.

The Pretty, But Deadly: Azaleas and Rhododendrons

These flowering shrubs are a sight to behold, with their vibrant blooms in shades of pink, purple, and white. Here in North Central Florida they’re everywhere. But don’t let their beauty fool you! All parts of azaleas and rhododendrons are toxic to horses, containing a nasty toxin called grayanotoxin. If your horse ingests even a small amount, it can cause severe problems like:

* Excessive drooling

* Loss of appetite

* Colic

* Muscle weakness

* Abnormal heart rhythm

* Coma

* Death

The Tall and Toxic: Red Maple Trees

Red maples are majestic trees that add a touch of autumn splendor to the landscape. However, their leaves, bark, and twigs contain a toxin called gallic acid, which can be harmful to horses. If your horse munches on these parts, especially in the fall when the leaves are wilted or dry, it can lead to:

* Severe anemia

* Colic

* Muscle weakness

* Kidney damage

The Unassuming Threat: Black Walnut Trees

These common trees might seem harmless, but their leaves, nuts, and bark contain a toxin called juglone. This nasty stuff can cause problems for horses, including:

* Laminitis

* Colic

* Diarrhea

* Skin irritation

The Bitter Surprise: Milkweed

While most horses avoid this plant due to its bitter taste, it’s important to be aware of its potential dangers. Milkweed contains a toxin that can cause serious problems if ingested, such as:

* Muscle weakness

* Seizures

* Respiratory difficulties

* Coma

* Death

The Hidden Danger: Poison Hemlock

This plant might look like harmless parsley, but it’s one of the most poisonous plants in North America. All parts of poison hemlock are toxic, and even a small amount can be fatal to horses. Branches falling into a water source can contaminate the water as well! Symptoms of poisoning include:

* Muscle tremors

* Convulsions

* Respiratory failure

* Death

Keeping Your Horses Safe: A Field Mouse’s Tips

Now, I know what you’re thinking: “Whinny, this is scary! How can I keep my horse safe from these sneaky plants?” Don’t worry, my friends, I’ve got some tips for you:

Know your pasture: Regularly inspect your pasture for any of the plants mentioned above. If you find them, remove them immediately. If in doubt, contact the local County Extension Service. It’s free and they are incredibly knowledgeable!

Provide good quality hay: Horses who are well-fed are less likely to nibble on potentially harmful plants.

Be aware of seasonal changes: Some plants become more toxic at certain times of the year, like red maples in the fall.

Contact my Doctors immediately: If you suspect your horse has ingested a poisonous plant, don’t hesitate to seek veterinary help. Time is of the essence in these situations.

Remember, knowledge is power! By being aware of the dangers lurking in your fields and pastures, you can keep your horses safe and healthy. And if you ever see a curious field mouse like me, don’t shoo me away! I might just have some helpful insights about the sneaky plants hiding in plain sight.

Until next week,

~Whinny

P.S. If you’d like to watch an entire Seminar video about poisonous plants put on by our local extension office, CLICK HERE. It’s a great presentation from a few years ago, very entertaining and very educational!

Hey everybody, Whinny here! Horses can be exposed to and graze on plants that can be harmful or even fatal. More often than not, horses will choose good quality grass or hay over a toxic weed or plant, especially if they have a good mouse friend to keep them out of trouble. However, over grazed pastures and the natural environment of Florida can predispose horses to be exposed to some toxic plants. In this blog post, we’ll explore several poisonous plants commonly encountered by horses: Red Maple, Acorns, Nightshade, Pokeweed, Creeping Indigo, and Fireweed. Understanding these plants and their potential dangers is critical for ensuring the well-being of our equine friends.

Red Maple (Acer rubrum)

   Red maple leaves, especially when wilted, contain a toxin called gallic acid, which attacks red blood cells. Ingestion of even a small amount of these leaves can lead to hemolytic anemia, methemoglobinemia, and potentially death in horses. Symptoms may include lethargy, dark urine, blue colored mucous membranes, jaundice, and colic.

Whinny’s Wisdom: Immediate treatment is crucial, including intravenous fluids, and supportive care.

Nightshade (Solanum spp.)

  Nightshade plants, known for their bell-shaped flowers and berries, contain the toxic alkaloid, atropine. Our savvy readers may be familiar with atropine as a topical used in treating eye conditions to dilate the pupil in certain situations. Ingestion can cause dilated pupils, nervousness, and irregular heartbeat. Luckily, the plant is bitter and not often eaten if there’s other food available.

Whinny’s Wisdom: Promptly diagnose and treat nightshade poisoning to minimize symptoms and complications.

Acorns (Quercus spp.)

   Acorns from oak trees are toxic to horses, primarily due to the presence of tannins. Ingesting acorns can lead to gastrointestinal upset, colic, and kidney damage. Chronic exposure may result in metabolic issues and laminitis.

Whinny’s Wisdom: Managing pastures to minimize exposure and providing ample forage alternatives can help prevent acorn ingestion.

Pokeweed (Phytolacca americana)

   Pokeweed is a significant concern for horses, as all parts of the plant are toxic and contain saponins, oxalates, and phytolacine. It can lead to severe gastrointestinal issues, including colic and diarrhea.

Whinny’s Wisdom: Early intervention is key, and treatment may include fluid therapy and medications to manage symptoms.

 Creeping Indigo (Indigofera spicata)

    Creeping indigo poses a serious threat due to its palatability to horses. Horses that consume this plant may experience a wide range of symptoms that could include corneal edema, mucosal ulcerations or neurologic signs that can range from dull attitude to narcoleptic-like behavior.

 Whinny’s Wisdom: Immediate veterinary attention is necessary to address neurological symptoms and provide supportive care. Heavy trafficked or overgrazed areas can perpetuate the weed.

 Fireweed (Urtica chamaedroides)

  Fireweed, also known as Heartleaf Nettle, contains stinging hairs that can irritate the skin and mucous membranes of horses. Ingestion can lead to lethargy or difficulty swallowing. More commonly, horses are seen due to urticaria, or hives, from skin contact. This plant can cause severe discomfort to the skin and horses may appear to have colic or neurologic signs.

 Whinny’s Wisdom: Address skin irritation promptly with appropriate care and remove fireweed from pastures if it is identified. It can often be found in areas with sparse grass growth, like feeding areas or near fence lines.

Conclusion

As veterinarians, it’s my docs’ responsibility to educate horse owners about the dangers of toxic plants like Red Maple, Acorns, Nightshade, Pokeweed, Creeping Indigo, and Fireweed. Encourage pasture management practices that minimize exposure to these plants and emphasize the importance of early intervention in cases of plant poisoning. By working together, we can ensure the health and safety of our equine patients and provide them with the best possible care.

Until next week,

~Whinny

P.S. Have you subscribed to this blog? Don’t rely on Facebook to let you know it’s out! If you’ll scroll down a bit more to the big purple box and give me your email address, I’ll send the blog right to you, and a day before it goes out to everyone else! Don’t take a chance on missing out on my mousy wisdom!

It’s poisonous plant season around North Central Florida, so I thought I’d drop a little plant wisdom on you humans. All of my poisonous plant wisdom has come from listening to seminars here at the clinic by really knowledgeable people from a place called the County Extension Service. They tell me they are a FREE service, and they can help with all kinds of things. If you’ve got questions about plants after reading my weekly dose of cat wisdom, I suggest you contact your local extension office. Heck, they’ll even come to your farm and check out your plants with you! 

Quick dog and cat tip before I begin, since we all love cats (and tolerate dogs): Lillies are deadly to cats in very, very small (like microscopic) amounts, and Coonti palms work the same way for dogs.

Red Maple

While beautiful, Red Maple trees are very, very bad for horses. Eating as little as 2 pounds of Red Maple leaves will cause toxicity in horses. Like many plants, wilted leaves contain the most toxin. The toxin, gallic acid, causes the body to attack and kill the red blood cells. This makes the blood unable to carry oxygen. Horses are affected within about 24 hours of eating. They become extremely depressed, and may even have blue mucous membranes. They will also urinate red or dark brown urine. There aren’t great treatment options for this toxin. The Docs give them lots, and lots, and I mean lots, of IV fluids. If they make it 36 hours, it’s very likely they will recover.

Since poisonous plants pretty much all look alike to me, I have included a picture of one.

Creeping Indigo

This is one horrible poisonous plant, and ‘Creeping’ is the key word. It creeps along very close to the ground, making it really hard to find. Creeping Indigo also spreads by long, hard-to-pull roots and seeds making it difficult to fully kill in one round. This plant makes you go to full-on war. 

Horses need to eat around 10 pounds of creeping indigo daily for about 14 days to develop signs. That seems like a lot, but some horses develop a taste for this weed and seek it out! The toxins are 3-nitropropionic acid (3-NPA) and indospicine. These toxins attack the nervous system in many weird ways. That means the symptoms of Creeping Indigo toxicity are difficult at best to figure out. They can vary from runny, squinting eyes, sleepiness, nystagmus (this is the fancy term for eyes wiggling back and forth), gait abnormalities, and mild colic-type signs. Yep, a wide variety. To add to the joy that is Creeping Indigo, there are no lab tests to identify the toxin, and no real way to know if it’s the cause of the problem. Special tests on tissue taken after an animal has passed away can identify the toxin.

Here’s a picture of Creeping Indigo to help you identify it, although it’s not always flowering, which really makes it hard. It will die if you spray it with Grazon, or other similar products, but you MUST pull up the dead plants since the seeds are still viable! The ways to hate Creeping Indigo are many.

Crotalaria

Crotalaria is commonly known as rattlepods or rattlebox, due to the sound of the seeds rattling in their pods. This one suckers you in with pretty flowers, then BAM! Your liver gets annihilated. This plant really starts growing in late summer, but if you look you’ll find it around right now.  It likes damp places, such as the area around the water buckets or troughs in your pasture.

It has big broad leaves with a spike of small yellow flowers, and commonly grows to 4′ in height. Luckily, crotalaria tastes very bitter, so unless animals are starving, they usually won’t eat it. Interestingly, some less-toxic strains of this plant are consumed by humans in various places around the world. It just proves my point that some people will eat anything.

This one will happily die with pretty much any plant killer, but it does like to come back every Fall.   

Oleander

This plant often gets planted as a decorative hedge. Horses think decorative hedges have been placed for snacking purposes. One mouthful of this hedge is enough to cause problems! In humans, a very small amount is enough to kill. The toxins in oleander are powerful cardiac poisons like digitoxigenin, and oleandrin. They target the heart muscle and cause it to die. 

Horses that eat oleander can show signs from poor performance to extreme lethargy, depending on how much they ate. All I have to say about this one is don’t plant it in the first place. It’s not good for your horse, your dog, your cat, or you. If you do have oleander, be very, very careful removing it. All it takes is some sap in a small skin wound to cause problems with human hearts! 

Nightshade

Last of the horrible Top 5 Poisonous Plants is nightshade. This fun little guy loves to grow along fence lines. Long ago, crazy humans used the plant to dilate their eyes since they thought it looked good. The main toxin in nightshade is atropine. My Docs use it as a drug in its purified form. If your horse eats nightshade, they will experience fun things like diarrhea, nervousness, irregular heartbeat, and extreme sensitivity to light. 

Luckily this guy also doesn’t taste very good. Keeping plenty of hay in front of your horses is a great way to keep them from checking out nightshade to see if it’s tasty. The easiest way to get rid of it is to check your fence lines regularly and simply pull them up. They should be thrown away or burned after removal since the berries remain toxic even when dried. 

Poisonous plants are no joking matter. These are just a few of the big culprits out there. Many humans don’t even know what they’ve got for poisonous plants without a little guidance from people like my Docs or their local Extension Agent. Good pasture maintenance creates a poor environment for most poisonous plants. Know who can help you with that? Your county Extension Agent! Now go walk those pastures to check your weeds.

Until next week,

~Tony

P.S. There’s a full seminar over on my YouTube Channel on poisonous plants, presented by the Alachua County Extension Office. The audio is rough in the beginning, but it’s full of great tips on how to identify things, eradicate things, and make your farm as safe as possible. You can watch that seminar HERE, and make sure you subscribe to my Channel while you’re there!

Poisonous Plants

Plants are delicious. Who doesn’t love to chow down on a plant the humans have carefully placed for decorative purposes? I know I do. I have learned, however, that not all plants are safe for eating. This rule applies to cats, dogs, and horses.  This week I’m going to educate you humans on the top 5 poisonous plants in the horse world.

Quick dog and cat tip before I begin: Easter lilies are deadly to cats in very, very small amounts, and Coonti palms work the same way for dogs.

Red Maple

While beautiful, Red Maple trees are very, very bad for horses. Eating as little as 2 pounds of Red Maple leaves will cause toxicity in horses. Like many plants, wilted leaves contain the most toxin. The toxin, gallic acid, causes the body to attack and kill the red blood cells. This makes the blood unable to carry oxygen. Horses are affected within about 24 hours of eating. They become extremely depressed, and may even have blue mucous membranes. They will also urinate red or dark brown urine. There aren’t great treatment options for this toxin. The Docs give them lots, and lots, and I mean lots, of IV fluids. If they make it 36 hours, it’s very likely they will recover.

Since poisonous plants pretty much all look alike to me, I have included a pictures of these various plants.

Creeping Indigo

This is one horrible poisonous plant, and ‘Creeping’ is the key word. It creeps along very close to the ground, making it really hard to find. Creeping Indigo also spreads by long, hard-to-pull roots and seeds making it difficult to fully kill in one round. This plant makes you go to full-on war.  Horses need to eat around 10 pounds of creeping indigo daily for about 14 days to develop signs. That seems like a lot, but some horses develop a taste for this weed and seek it out! The toxins are 3-nitropropionic acid (3-NPA) and indospicine. These toxins attack the nervous system in many weird ways. That means the symptoms of Creeping Indigo toxicity are difficult at best to figure out. They can vary from runny, squinting eyes, sleepiness, nystagmus (this is the fancy term for eyes wiggling back and forth), gait abnormalities, and mild colic-type signs. Yep, a wide variety. To add to the joy that is Creeping Indigo, there are no lab tests to identify the toxin, and no real way to know if it’s the cause of the problem. Special tests on tissue taken after an animal has passed away can identify the toxin.

Here’s a picture of Creeping Indigo to help you identify it, with chapstick container for size reference. It will die if you spray it with Grazon, or other similar products, but you MUST pull up the dead plants since the seeds are still viable! The ways to hate Creeping Indigo are many.

Crotalaria

Crotalaria is commonly known as rattlepods or rattlebox, due to the sound of the seeds rattling in their pods. This one suckers you in with pretty flowers, then BAM! Your liver gets annihilated. This plant really starts growing in late summer. It like damp places, such as the area around the water buckets or troughs in your pasture.

It has big broad leaves with a spike of small yellow flowers, and commonly grows to 4′ in height. Luckily, crotalaria tastes very bitter, so unless animals are starving, they usually won’t eat it. Interestingly, some less-toxic strains of this plant are consumed by humans in various places around the world. It just proves my point that some people will eat anything.

This one will happily die with pretty much any plant killer, but it does like to come back every Fall.   

Oleander

This plant often gets planted as a decorative hedge. Horses think decorative hedges have been placed for snacking purposes. One mouthful of this hedge is enough to cause problems! In humans, a very small amount is enough to kill. The toxins in oleander are powerful cardiac poisons like digitoxigenin, and oleandrin. They target the heart muscle and cause it to die. Horses that eat oleander can show signs from poor performance to extreme lethargy depending on how much they ate. All I have to say about this one is don’t plant it in first place. If you do have oleander, be very, very careful removing it. All it takes is some sap in a small skin wound to cause problems with human hearts! 

Nightshade

Last of the horrible Top 5 poisonous plants is nightshade. This fun little guy loves to grow along fence lines. Long ago, crazy humans used the plant to dilate their eyes since they thought it looked good. The main toxin in nightshade is atropine. My Docs use it as a drug in its purified form. If your horse eats nightshade they will experience fun things like diarrhea, nervousness, irregular heartbeat, and extreme sensitivity to light. Luckily this guy also doesn’t taste very good. Keeping plenty of hay in front of your horses is a great way to keep them from checking out nightshade to see if it’s tasty. Most of the time this one can be treated with time. The easiest way to get rid of it is to check your fence lines regularly and simply pull them up. 

Poisonous plants are no joking matter. The best way to know what you’ve got? Call your County Extension Service and have them come walk your property. County Extension Agents are full of all kinds of useful knowledge about plants and grass. Best of all, they are part of your tax dollars at work!