Here in the UK we have very wet, cold winters. Our horses either get very little turnout during the winter months, or when they do go out, the fields are muddy and bare. Our spring can be quite unpredictable, either it stays wet and cold, or it’s hot and dry, meaning the grass doesn’t grow. Then almost overnight, the conditions change and bright green grass shoots up. Horse owners everywhere breathe a sigh of relief, start turning their horses out more and rejoice in the fact that they won’t need to feed as much hay. But how many of us actually stop and think about the risks of summer grazing poses to our horses?
It’s not just natives at risk of summer grazing
I think part of the problem is when we think “spring grass” we think “native ponies.” Yes, they are typically at a higher risk of conditions such as laminitis, but all horses can react badly to spring grass. It’s also not just those we consider good doers who are at risk. All horses are at risk and horse owners should be considering these risks when turning out on fresh grass.

What are the risks of summer grazing?
There are plenty of risks of summer grazing, from the dreaded laminitis to fresh horses injuring themselves.
Cases of colic increase with fresh grass
When the spring grass finally comes through many vets see a spike in colic cases. We had a case of colic at our yard this year, suspected to be gas from too much rich grass. This was the first time we had had a case of colic in my 4 years at this yard, so while it’s something we all keep in mind, it did take us all by surprise.
Fresh grass usually causes colic by disrupting the bacteria in the horses gut. The gut bacteria are a big part of the digestion process in horses. This is why we make feed changes slowly, so we don’t disrupt the bacteria too much and to make sure there are enough of the right bacteria in there to digest what we are feeding them. When a horse has had limited or poor quality grazing and then start eating the new spring grass, this can overload the bacteria in the gut. This can lead to colic.
Laminitis a big consideration on fresh grass
Once the grass shoots up, there is a spike of cases of laminitis. There have been many theories as to why this happens over the years. But the current belief is that the extra sugar in the grass can effect the blood insulin levels, which in turn leads to laminitis. While laminitis is mainly associated with native type horses and ponies, possibly due to them being more likely to struggle with insulin regulation, laminitis can affect any horse.
One thing what really concerns me is how blasΓ© some people are about laminitis. Yes it can be very common, but that doesn’t make it any less serious. Something what has really stayed with me is a vet saying “laminitis is an emergency, just like colic.” If your horse has any signs of laminitis you should be talking to your vet as the earlier you act, the better the outcome. For mild cases you might not need a vet visit, but I would always be phoning up and asking advice.
Increasing obesity in horses
It is natural for horses to put on a bit of weight over the summer, but it is also natural for horses to lose this extra weight over the winter. Horse owners are a bit paranoid about their horses losing weight. This combined with better management and equipment available, many horses don’t lose any weight over the winter. So when the fresh spring grass and longer summer grazing comes around, they put on a bit more weight each year, without really losing it.
Obesity is a huge risk to horses in the UK. One vet practice believes they put down about 30 horses a year due to obesity. We know that obesity increases the risk of conditions such as laminitis. But it can also be a factor in other injuries, such as tendon injuries, not healing.
Fresh, fizzy horses
Many horse owners will have experienced the fizzy behaviour what sometimes come with fresh spring grass. While this in itself isn’t a health risk, if your horse is prone to silliness, they might be more likely to injure themselves when the grass comes through. One of my vets recently said she usually sees a slight increase in field injuries when the grass comes through. If they can be silly to handle or to ride when they get a bit fizzy, they could also be putting you at a higher risk than usual. So it is certainly something to bare in mind.
What can you do to reduce the risks of summer grazing?
No matter your horse and how you manage them, you should always bare fresh spring grass in mind and should be ready to make changes over the summer if needed. These changes could be big, small, permanent or temporary. But you should always have a few plans in the bank as you never know when you might need them. Here are some of my top tips for reducing the risks of summer grazing.
Reduce their grazing on fresh grass
If you can reduce the amount of fresh grass they are eating, you are not only reducing the calories from this, but also less sugar, which is often the bigger problem. There are so many different ways you can do this, depending on whether you are more concerned by calories or sugar.
Limiting their turnout time
One quick and easy change you can make is to limit their turnout time. Our horses usually go out from 7am to 6pm over the summer. But after our grass shot up, they came in between 1-2pm instead for a week. This doesn’t work for all horses as horses can eat their entire daily allowance in 3 hours. So unless you are turning out for less than 3 hours, it might not be enough for your horse.
Limiting the grazing available
There are a few ways you can do this. You could strip graze, use a starvation paddock or use a grazing muzzle. But the aim of this method is letting them still graze as normal. But they won’t be able to get as much as the fresh spring grass, meaning less sugar and calories.
Change when they are grazing
If you are particularly worried about the sugars in the grass, you can change when they go out to avoid the times of day when the sugars are highest. Typically first thing in the morning when there is frost or heavy dew is when the grass has the most sugar in it. Waiting until later to turn out can stop your horse getting this extra sugar.




Reduce their overall calorie intake
Just like us, reducing their calorie intake will hopefully stop them putting on weight and might even be enough to help them shed some extra pounds. Whether or not you think your horse is prone to ulcers, I personally don’t like horses being left without forage for hours. While it can be really important to really restrict some horses, I think there are other things you should try first.
Trickle Feeding
If your horse doesn’t live out, you can look at trickle feeding them in the stable. The idea behind trickle feeding is that you feed them less, but in a way what takes them longer to eat. From small holed haynets, haybags, to putting their feed in treatballs, there are plenty of ways to slow your horse down so they end up eating less while still having constant access to forage.
Soaking Hay
Soaking hay breaks down some of the sugars in hay, meaning the horse will get less calories from it. For best results you really need to soak the hay for about 12 hours, but really even soaking for a few hours should make a small improvement. This means you can feed your horse a bit more hay, so they don’t run out, but will get less calories that unsoaked hay.
Reduce their hard feed
Most horses won’t need as much hard feed over the summer, especially if they are a good doer. For horses in work I always like to make sure they are fed some hard feed, purely to make sure they are getting everything they need. But with so many low calorie balancers on the market, even good doers can get a hard feed without extra calories. If your horses is getting more fresh grass than they were, you should look at reducing or changing their hard feed.
Slowly increase exercise
Just like us, if we exercise more, we burn more calories. If your horse is in work and is having more grass, you might want to slowly increase their exercise. This could be anything from slowly increasing the difficulty of their schooling, to just going on an extra walk around the block each week.
If they aren’t in work, or you don’t want to increase their workload, you can look at increasing the time they spend walking. Track systems have become quite popular recently. This is basically where you section off parts of your field so they have to walk further to get to different things in the field such as the water and the hay.
Extra protection
If you are most worried about extra injuries from having a bit too much extra energy, you can look to add some more protective wear and procedures. You might want to turn them out in brushing boots or turnout boots. You might want to handle them in gloves, hat or even in a bridle when you usually use a head collar. You might want to keep their exercise a bit simpler, more lunging and flat work, less jumping and hacking.
You will know what your horse responds best to, what keeps them more manageable and what fires them up. Use this to make any small changes you think will help keep you both safe until they settle back down again. There is nothing wrong with putting something in place to help cope with the temporary behaviour changes.