08/09/2023
For all of my friends that own, train, or care for horses. This is a MUST READ...
What is the longest a horse can safely go without food?
Answer from a veterinarian-
More and more I see horses and ponies stood for long periods of time with no hay or haylage. Usually under the guise of a “weight control diet”. So how long can a horse be without food before damage is done? And what damage is done?
For those with a short attention span, I’ll give you the answer to begin with - 4 hours, maximum.
Why?
Horses are grazers. They are designed to eat constantly. They have no way of storing their acids and digestive enzymes, they’ve never needed to. They have no gall bladder to store bile and their stomachs release acid constantly, whether or not there is food in the stomach and intestines.
A horses stomach only holds approximately 8-15 litres. Depending on the substance eaten, it takes on average 4-6 hours for the stomach to completely empty. After this, the acids and enzymes start to digest the inside of the horses stomach and then the intestines. This causes both gastric and intestinal ulceration. It has been estimated that 25-50% of foals and 60-90% of adult horses suffer from ulceration. But I won’t go into detail about this, there is a lot of information around about ulcers.
So is that it? Are ulcers the only concern?
No, having an empty stomach is a stress situation for a horse. The longer they are starved, the more they release stress hormones, cortisol predominantly. Cortisol blocks insulin and causes a constantly high blood glucose level. This stimulates the body to release even more insulin, and in turn this causes fat tissue to be deposited and leptin resistance. Over time this causes insulin resistance (Equine Metabolic Syndrome). All of these mechanisms are well known risk factors for laminitis and are caused by short term starvation (starting roughly 3-4 hours after the stomach empties). Starving a laminitic is literally the worst thing you can do. Over longer periods, this also starts to affect muscle and can cause weakness, and a lack of stamina so performance horses also need a constant supply of hay/haylage to function optimally.
Let’s not forget horses are living, breathing and feeling animals. We talk about this stress reaction like it’s just internal but the horse is well aware of this stress. Door kicking, box walking, barging and many other stable vices and poor behaviour can be explained by a very stressed horse due to food deprivation (we all have that Hangry friend to explain this reaction). Next time you shout or hit a horse that dives for their net, remember their body is genuinely telling them they are going to starve to death. They know no different.
But surely they spend the night asleep so they wouldn’t eat anyway?
Not true. Horses only need 20mins REM sleep every 24 hours (jealous? I am!). They may spend a further hour or so dozing but up to 22-23 hours a day are spent eating. So if you leave your horse a net at 5pm and it’s gone by 8pm, then by 12am their stomach is empty. By 4am they are entering starvation mode. By their next feed at 8am, they are extremely stressed, physically and mentally.
Now I know the many are reading this mortified. I can almost hear you shouting at your screen “if I feed my horse ad lib hay he won’t fit out the stable door in a week!!”
I will say that a horse with a constant supply of hay/haylage will eat far less then the same horse that is intermittently starved. They don’t eat in a frenzy, reducing the chance of colic from both ulcers and over eating.
Don’t forget exercise. The best way to get weight off a horse is exercise. Enough exercise and they can eat what they want!
Written by Vikki Fowler BVetMed BAEDT MRCVS
A few edits for the critics-
Firstly, feeding a constant supply does not mean ad lib feeding. It means use some ingenuity and spread the recommended amount of daily forage so the horse is never stood with out food for more than 4 hours. I am not promoting obesity, quite the opposite, feeding like this reduces obesity and IR. This can be done whilst feeding your horse twice a day as most horse owners do. Just think outside the box. Hang a hay bag or hay net*is one solution. Every horse/pony and situation is different, but this is a law of nature and all horses have this anatomy and metabolism. How you achieve this constant supply is individual, the need for it is not.
*the use of hay nets in the UK is very very high. I’d estimate 95% of horses I see are fed this way and very very few have incisor wear or neck/back issues as a result. Yes, feeding from the ground is ideal, but a constant supply, I feel trumps this. Again with ingenuity both can be safely achieved.
Final finally 🤦♀️ and I feel I must add this due to the sheer number of people contacting me to ask, feed your horses during transport!!! I am astonished this is not normal in other countries! Again in the UK, we give our horses hay nets to transport. We don’t go 10 mins up the road without a haynet and a spare in case they finish! Considering we are a tiny island and we rarely transport even 4 hours, we never transport without hay available. I have never seen an episode of choke due to travelling with hay available. If you are concerned, use a slow feeder net so they can’t take too much in at once.
If you get to the end of this post and your first thought is “I can’t do this with my horse/pony, they’d be morbidly obese”, you haven’t read the advice in this post thoroughly.
Thanks Trish!!
