The Equine Expert

Ask the Expert – 5 questions about the risk of overgrazing and how to reintroduce horses back to grass!
By Tanja Schnuderl

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Tanja Schnuderl is a member of The Equine Expert LLC. She provides consulting and expert witness services specializing in barn management, horse behavior and appraising. Spring has sprung and the grass is growing, which means that a lot of horses are returning to their grass pastures. We talked to Tanja Schnuderl about tips to reintroduce horses back to grass and potential risks of overgrazing.

What are the risks of overgrazing?
We all know how complex and sensitive a horse’s GI tract is. Whenever there is a change in a horse’s diet, you always want to closely monitor them and double check that the horse is adjusting well. Switching from hay to grass in spring is a big change in their diet and needs to be treated just like that. Overgrazing can cause horses to colic. The ingestion of lush grass is also one of the primary causes for laminitis or “founder” (while the two are technically not the same, the terms are commonly used interchangeably within the equine community). Eating excessive amounts of grass, before their system had time to adjust to the change in diet, can cause this extremely painful condition in horses. Severe cases of laminitis can result in the horse being euthanized.

How do you get horses safely back on grass again?
That depends on what the winter situation of your horses is and if they have access to grass year around. In states with a winter season, barns often have horses in a paddock with hay, so the grass can grow and then switch the horses back into grass fields in spring. If that’s the case, you want to take it slow and steady when introducing them back to grass. Once the grass is growing and they have nibbled on the tiny bit of grass in their winter paddock, horses can get turned out in their grass field for 2 hours. The following day the turnout time can be increased to 3hrs, the day after that turnout will be for 4hrs, and so on until you reach the time limit on what your general turnout situation is.

What symptoms or signs should we look out for in our horses while they return to grass?
As barn manager, I monitor the horses closely every day for any signs and symptoms of sickness or injury. Part of my daily routine during AM and PM feed is to check if all horses are eating fine. Equally if not more important is to check what their poop looks like. No poop or very runny poop (diarrhea) are concerning, cow-like poop should be monitored, etc.
During the days when we reintroduce horses to grass, I also pay close attention for laminitis warning sings. Laminitis symptoms include the lameness in both front limbs (or all four) and the horse standing rocked back with the weight on their hind feet.

Don’t forget to adjust their grain intake!
A lot of horses get additional grain during the winter for different reasons e.g., to make up for the lack of grass, or to get a bit more weight on older horses during the cold days. However, once they are back on grass you want to take a close look at your feed board and check if you need to adjust the daily grain for your horses. Horses typically pick up weight quickly, once they are being turned out on grass.

Watch out for warm days with freezing nights!
This goes for fall days as much as spring days. There is a correlation between a rapid change in temperature and sugar content in grass. If the days are warm and sunny, the sugar content in the grass increases (so that the grass can grow during the night). If during the nights the temperature drops below freezing, the grass can not grow and the increased sugar content is still stored once the new day starts and the temperatures rise again. This leads to grass with and increased sugar content, which is super yummy for horses but can cause horses to potentially overgraze and an increased risk of laminitis.

Tanja Schnuderl is a team member with The Equine Expert LLC, a multi-discipline equine expert witness and consulting firm with expert equestrians offering legal expert witness and consulting services in court cases and legal matters. Tanja is an expert on Barn Management and Horse Behavior.  She is the Barn Manager for Moon Rising Farm just outside Washington DC and Principal of Sigma Equine LLC, an equine appraisal business. Tanja grew up in Germany and was a paralegal for many years.  For more information on Tanja Schnuderl email,

Laminitis in Horses | American College of Veterinary Surgeons - ACVS
Laminitis: Prevention & Treatment | AAEP
Cold Weather  - The Laminitis Site


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