Scientific and Equine Consultant

What might be some of the reasons why my horse has lost his appetite?

What Might be The Reasons Why My Horse Has Lost His Appetite?

Dr David Marlin

Today it seems we are more likely to hear about concerns with overweight horses than those that are underweight, but appetite is important for maintaining your horse in a healthy state and it can be worrying for owners when horses appear to go off their feed. However, even a horse that is on the thin side is in no immediate danger as long as it is drinking and eating sufficient forage to maintain hindgut function.


Illness & Pain

One of the most common reasons a horse may suddenly go off his food is because he is not feeling well or is in pain. Horses usually have a depressed appetite in the early stages of infections by viruses or bacteria and so it can be worth checking for other clinical signs, such as a raised temperature, nasal discharge or swollen lymph nodes under the neck. Other common causes of pain or discomfort which can reduce appetite include gastric ulceration, dental problems, hindgut disturbance, musculoskeletal problems or pain following surgery.


Has your food gone off, been contaminated or is it a bad batch?

Another obvious reason why your horse may be backing off his feed is that there is something wrong with it. Check that the feed smells and looks as expected and ask anyone else you know who may be feeding the same feed. If they have had similar problems or contact the manufacturer. If the food does have something wrong with it then chances are you will not be the only one calling them up and they should put two and two together. Any feed with oil in is at an increased risk of spoilage in warm weather due to oxidation of the oils which can lead to the feed being unpalatable.


A sudden increase in training intensity?

Horses may also temporarily lose appetite for a short period when they move from moderate to hard work and especially if they are competing. This will also be more likely in hot weather. Sometimes some horses have trouble eating the “right” amount of hard feed for the work they are in. If this could be the problem, then moving towards high energy dense feeds such as linseed will often help reduce the volume of feed the horse must eat but at the same time deliver the required amount of energy.

Obviously if you have recently changed your feed then it may be your horse simply doesn’t like it. Just like people, not all horses like the same things.  When changing to a new feed you should always start by mixing a little of the new in with the old and gradually change until it is all new over a period of 10-14 days. This not only reduces the risk of hindgut upset but also reduces the risk of rejection.

If your horse has worked very hard at a competition then whilst we would imagine that he would be hungry, in fact the opposite may be true and he may have a decreased appetite, especially if he is dehydrated.


Hot weather

In the Summer when it is hotter in theory your horse should need to eat more as he will be using up more energy to keep cool (through sweating and breathing), however, like ourselves, horses  may also have times when appetite is reduced. If a horse is being bothered by flies this may also put them off eating.



It is conceivable that some horses could get bored with their feed, but not in the same way that we recognise that eating the same food each day would be boring for us. If there is nothing obviously wrong with your horse then using some dried herbs or chopped succulent carrots or apples may help stimulate appetite. But beware. Once you start your horse may expect this treatment every day! It’s also important to watch for horses that may be low in the pecking order which can be bullied by others leading to depression and poor appetite.


Over-facing: overestimating how much feed your horse actually needs

Overestimating how much feed a horse needs is another potential reason why a horse is not eating everything put in front of it. In this case it is not that the horse has lost its appetite it just that its appetite has been exceeded and it knows when to stop!


Older horses

Older horses may also have a reduced appetite in the same way that older people do. They may not be as active and therefore it’s easy to overestimate their energy requirements and try to feed them too much. If they do have a decreased appetite and are failing to maintain condition then energy dense oil based feeds are the way to go.



It is not unusual for horses to lose their appetite slightly from time to time and this may happen for no apparent reason or for obvious reasons such as the food being off, pain or discomfort, infectious disease, transport, hard work, etc. But in most cases reduction in appetite usually lasts only a few days. If poor appetite is an ongoing problem then switching over to energy dense high oil based feeds is an easier and safer way to ensure horses get the energy they need. If reduction in appetite occurs suddenly and for no obvious reason and persists for more than a few days then it will obviously be important to consult with your vet to ensure there is no serious underlying health problem related to the loss of appetite.

Date: September 08, 2015