Donna Campbell Smith is an author, freelance writer, and photographer. She has an AAS degree in equine tech and is a certified instructor.
What Is Slobbers and What Causes It?
You bring your horse in from the pasture and are alarmed to see saliva pouring out of her mouth. Standing in the cross ties while you groom her, she drools a puddle on the floor.
What in the world is wrong? Does this warrant a vet call? Is this a dangerous situation or just a messy one? Why is one horse slobbering and another is not? And why is your horse slobbering this particular year after years of grazing in the same pasture?
Slobbering (Drooling) May Be Caused by a Fungus Found on Clover
What your horse is likely suffering from is "clover slobbers."
Which types of clover or plants cause horses to drool?
Red clover seems to be the most likely species to cause this condition, but all clovers and legumes can host the fungus that causes slobbers. It is not actually the plant itself causing this problem, but a fungus that grows on the plant or hay made from red clover. The fungus Rhizoctonia leguminicola produces a mycotoxin called slaframine.
The fungus flourishes in cool, wet, and humid conditions. It appears in late spring and early summer and even in fall months as tiny black specks on the clover plants. It is so small that it is difficult to see with the naked eye.
Some horses apparently really love clover, while others can take it or leave it, which explains why some horses are affected and others are not. Some horses may be more susceptible than others to the mycotoxins.
What else might cause a horse to slobber?
That being said, mechanical or chemical reactions to plants can also cause salivation. Irritation from the hairy stems of clover can cause this gross reaction, and plants other than clover including burdock and foxtail can also cause slobbers. One common plant that can cause a chemical irritation is buttercups. The best defense from these weeds is to keep your pastures mowed regularly.
Hay made from the clover can also cause salivation if it contains the fungus. The most immediate danger from clover slobbers is dehydration since the horse is losing fluids from the salivation.
How to Treat a Slobbering Horse
- The first thing to do to "cure" slobbers is to take the horse out of the pasture. The slobbering will cease within 24 hours.
- Be sure the horse drinks plenty of water.
- If you notice any symptoms other than the slobbering, or the slobbering does not subside within two days call your vet. He may prescribe an antihistamine.
- Mowing the pasture and removing the infected plants can alleviate the problem.
Is Clover Slobber Dangerous?
While clover slobbers is not life-threatening, severe problems can arise if the horse is exposed to the infected clover for a long period of time, including colic and founder.
This article is accurate and true to the best of the author’s knowledge. It is not meant to substitute for diagnosis, prognosis, treatment, prescription, or formal and individualized advice from a veterinary medical professional. Animals exhibiting signs and symptoms of distress should be seen by a veterinarian immediately.
Donna Campbell Smith (author) from Central North Carolina on July 31, 2012:
Niki, a runny nose could be allergies or upper respiratory infection. You should check with your vet if it doesn't clear up in a few days.
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niki on July 31, 2012:
My horse has the slobbers and a runny nose... is that from eating clovers?
Donna Campbell Smith (author) from Central North Carolina on June 28, 2011:
Phyllis, the only thing I can suggest is maybe sectioning the area into smaller paddocks by running a hot wire to limit how much they eat. But hay is probably the most sensible solution. It is better than a vet bill, or losing a horse to founder and colic.
Phyllis Staver on June 27, 2011:
Tonight I just brought my two mares in from the pasture that has white clover and both of them had degrees of colic. This has not happened before this particular year, but it has been VERY wet in Ohio for many weeks. I am certain that it's the way the pastures are growing with perhaps that fungus present. Several years ago we had a purebred Arab mare founder on it. This makes me angry since we equine owners have no control over weather conditions; yet we get to make late at night trips to the vet to get medicine to help our beloved horses recover. It's SO frustrating. I hate feeding hay in the summer, but I don't want sick horses either! It's too early (June) to wish for a frost. So what do you do?
Donna Campbell Smith (author) from Central North Carolina on June 27, 2011:
Andrew, they can still get slobbers from dried clover in hay, etc. The only danger I know of is dehydration if they are not getting plenty of water since they are losing fluid when they slobber.
ANDREW on June 26, 2011:
ALL THREE OF MY DRAFT HORSES AS OF TONIGHT HAVE THE SLOBBERS, FROM I,M GUESSING, CLOVER INTAKE. THEY GRAZE ALL DAY ON 13 ACRES.iT'S EVERYWHERE. OUR OHIO 1ST CUT IS ALREADY CUT,BAILED AND STACKED IN OUR HAYLOFT.IS THER AN ACTIVE INGREDIENT IN DRIED CLOVER THAT CAN STILL HARM THEM
Mary L. Stephens on July 13, 2010:
Very informative, useful and a help - thank you!
proudgrandpa from Charlotte, NC on July 18, 2008:
I think my neices baby has been eating clover. Oh, I guess that isn't the same as teething.
Very informative hub, I had never heard of Clover Slobbers. Thanks for the hub. NEIL