The days are really starting to stretch now and there does seem to be light at the end of the tunnel.

As we all look forward to long summer days and (hopefully) warmer and drier weather, the advent of spring and all that it brings will fill some equine owners with a degree of trepidation.

For some equines and their owners, the spring flush can be a pretty traumatic time.

Dr Green

There is nothing better than watching a herd of contented horses munching on a sward of fresh, green grass. Traditionally, Dr Green was seen as the cure-all for any winter ailments as horses were turned out for summer.

Nowadays, it seems that more and more of us find spring a very stressful time. The first shoots of spring grass should have a health warning on them for many equids.

Even before we, mere humans, are aware of it happening, the grass will start to grow through the old dead sward that has accumulated over the winter or through the mud and bog (depending on your situation).

This is the first problem – it is eaten as quickly as it is grown and most folks will see that there is still nothing much to eat, so no need to worry yet.

Look out for less consumption of any hay offered, a change in consistency and colour (to green) of their poo and excess gas. All of these can provide clues to the fact that your horse is getting access to more grass than he is letting on!

Growth flush

The next problem is that this first flush of spring grass is very sweet and attractive to horses.

Grasses store sugars near the base of the plant, so when your horse nibbles on short grass, he is getting a high sugar parcel.

This means that even though he may be just nibbling, there can still be too much sugar and fructans (the storage carbohydrate for grass) for sensitive individuals.

Clover also starts to peep through and it can also cause issues, as its storage carbohydrate is starch. Clover has no place in a field with horses and unfortunately tends to take over the sward if left unabated.

Try to reduce the amount of clover in your sward year on year.


This high sugar grass can easily set off laminitis in sensitive animals due to the effect that is has on blood glucose and insulin levels.

It could also set off laminitis in a horse that has never had laminitis before but who, unbeknown to the owner, has been sitting on a metabolic (EMS) knife edge for months, maybe even years.

Gassy bellies

For those who show their sensitivity to this sudden increase in sugars and starch (from clover) by exhibiting bouts of gassy colic, this can also be a dangerous time of year.

These horses tend to gorge themselves as soon as a fresh bite of grass is available, overwhelming the digestive system and upsetting the gut flora.

This results in increased fermentation and gas build up in the hindgut, which can lead to a very painful colic.

As a double whammy, this type of colic and the upset to the gut environment can oftentimes end up as a laminitis case too.

Spring fling!

The other issue that is heralded with the return of spring grass, is more of a behavioural issue.

Many horses undergo a personality transplant at the time that spring grass starts to come through.

Increased sugar levels in the diet mean an increase in fast release type energy available to the horse and that, in conjunction with the possibility of an upset gut, can make for a rather lively and/or grumpy ride.

There are some thoughts that low levels of magnesium in lush grass is also responsible for some undesirable behavioural traits, hence why many of the calmers on the market rely on magnesium.

Grass sickness

Spring time also sees an increase in the number of grass sickness cases.

Whilst this can hit at any time of the year, the majority of cases occur between April and July, with a peak in May.

Despite more than 100 years of research, the causes of this awful disease are still not fully understood but the current research is pointing towards a soil borne organism as the likely culprit (clostridium botulinum).

As horses are nibbling at short, sweet grass, they are very close to the soil, especially if paddocks are poached or fairly bald, this in conjunction with a disturbed gut microflora population could allow this dreaded disease to take hold.


At the first signs of milder and sunnier weather – normally from March onwards – sensitive individuals and their grazing should be closely monitored.

Highly sensitive individuals might need to be secured away from grazing altogether and kept in an area without grass – on hard standing, arena or stable – until the spring danger time is over.

Protective factors for all of the above spring issues include:

n Offering hay at all times (this is particularly important where grass sickness is a potential worry). Hay ensures that the fibre content of the diet is maintained and helps to stabilise the gut microflora.

n Soaked hay is useful for good doers and insulin sensitive individuals as it helps to reduce the sugar intake of the horse.

n Using digestive enhancer supplements, such as Yea-sacc, to help to stabilise gut microflora.

There are also supplements available that will help control excess fermentation and/or gas build up to lessen the risk of grass colic. Different supplements work for different horses.

n Restrict access to grazing by the use of strip grazing, track systems etc depending on your facilities and horses.

n Ensure that daily requirement for vits and mins and salt are being met. Pay particular attention to selenium and vitamin E levels as these powerful antioxidants ensure that your horse’s immune system is kept healthy.

Horses will very often lick and eat soil if they are short of salt and/or trace elements and this habit is best avoided if possible.

n Horses also require trace elements and quality protein to enable them to mobilise fat and digest nutrients correctly. Try the use of a low calorie balancer pellet.

n Muzzles will allow a horse to stay with its field mates whilst reducing grass intake and it is harder to get at that short, sweet grass when wearing a muzzle. Muzzles will work well for colic-prone gorgers.

Longer term strategies

If you are lucky enough to have your own land, it is worth while looking at longer term strategies to help with sensitive individuals:

n Resow with older, traditional grasses, which provide a slower year round growth, rather than an early flush.

n Only use fertilisers if required. Get your soil analysed and top up accordingly. Use slow release, low nitrogen fertilisers to avoid massive grass flushes.

n Set up a semi-permanent track that horses can be moved on to early in the season (once all the mud has gone) and/or create a hard standing area. This can be a God send for EMS and laminitis-prone horses as well as those prone to gassy colics.

Supplementation with soaked hay or forage analysed as low in sugar is the key to the success of these systems.