EQUINE obesity is rightly seen as one of the biggest welfare issues facing horses currently and there are a range of factors that can contribute to it: feed type and amount, amount and intensity of exercise, forage type and amount et cetera. One of the most important factors though, and usually the one that determines the others, is whether the horse’s owner thinks that it is underweight, appropriately conditioned or overweight.

In a recent study, two members of the UCD Equine Clinical Studies research group visited owners and their horses and ponies at their home yards. A mix of breeds, ages, activities and heights were included. As part of a general health assessment, each horse or pony’s body condition was assessed by an equine vet using the 9-point Henneke scale, one of the most widely used scales for assessing body condition score (BCS). The owners answered questions on all aspects of their horse’s health and management including how they monitored weight and/or body condition and were asked to indicate where they thought their horse was on the scale from poor to extremely fat.

From the vet’s assessment of the horses and ponies taking part in the study, 45% were overweight, 3% were underweight and 52% were appropriately conditioned. While this was the first study to look at an Irish population of sport and leisure horses, proportions match figures found in Scotland where management practices would be similar to Ireland.

Looking at the owners’ perceptions of their horses’ condition, what we found was that owners of both underweight and overweight horses thought that their horses were closer to ideal than they actually were, with the owners of the most overweight horses and ponies being most inaccurate. A number of owners of horses and ponies who were BCS 8 (fat) thought that their animals were BCS 5 (moderate).

Henneke scale

As part of this study, we also gave the owners information on the Henneke scale and how to use it and asked them to apply it to their horse or pony and come back to us with a second score. We had expected that this would lead to improved accuracy from their first scores but surprisingly it didn’t, and some owners actually got worse, specifically the owners of those horses and ponies most at risk of obesity-related diseases or conditions.

We also identified, through the yards that had multiple participants sign-up, what are termed “yard cultures” when it comes to equine obesity and condition monitoring. This is where owners and horses in the same yard will show similar results. For example, in one yard, which was lucky enough to have a weigh scales on site, the accuracy of the owners perceptions was over double that of the study population in general; in a second yard, where the participants took monthly photos to monitor condition, their accuracy was 50% higher than the average; but in a third yard, where only one participant mentioned monitoring condition in a specific way, accuracy was only half that of the population average. When it came to the actual condition of the horses and ponies in each yard, at least 75% of the horses and ponies in the first two yards were in appropriate condition whereas two thirds of those in the third yard were overweight. This indicates that the horses and owners you and your horse are surrounded by can influence your horse’s condition and your perception of it.

Good practice

You might be thinking this is a horse owner problem but it’s not; it’s a human being problem! Similar inaccuracies have been shown for people and their pet cats and dogs, parents and their children, even GPs and their patients. So, what can you do as an owner to help you and your horse or pony in this regard?

The first, and most important thing, is to listen to and heed the advice of your vet and farrier. Discussions around weight can be awkward so it may be good practice to open the conversation, even if you think your horse or pony is in perfect condition, by asking your vet what they think of your horse’s condition at their vaccination visit.

The next thing would be to use a specific means to monitor your horse’s condition. Methods used can include weight tapes (there is discussion about how well weight tape measurements actually relate to weight but as we’re talking about monitoring here, the important thing is to use the same method in the same way consistently), regular photos or indeed using a BCS system such as the Henneke scale (this may be more accurate when used by individuals with more extensive experience; we hope to research this hypothesis in the future).

An important thing to note is to not assume that because your horse is older, it’s automatically going to be thin or that because it’s a cob, it’s automatically going to be overweight and there’s nothing you can do about either of those things. Again, talk to your vet to get advice on managing weight if you notice your horse is unintentionally losing or gaining weight. Similarly, horses of any breed can be overweight or underweight.

Finally, try to be aware of factors, such as the yard culture you’re surrounded by or even previous weight-related issues that may make you more prone to overestimating (for example, if you’ve had a laminitic horse) or underestimating (if you’ve had a poor-doer) condition, that can affect the accuracy with which your perceive your horse or pony’s condition.

In the future, the ideal would be to develop a system of condition monitoring that is not based on subjective assessments. There have been some developments in this regard using calculations involving morphometric measurements but these haven’t yet been tested outside controlled conditions. In the meantime, taking the steps above and being proactive about your horse’s weight will help you keep your horse or pony in the correct condition.