By Dr. Wendy Pearson, Ph.D. (Dr. of veterinary toxicology)

There are few things we humans are more sensitive about than our body weight. Where the rest of the world sees our gentle curves and happy smiles, we see lumps and wobbles and wrinkles. We generally have a far worse opinion of our own body condition than do any of the people around us. I would hazard that this is because our friends and family care about us and see the best in us, and recognize that while we may have a few extra curves we are healthy and happy, and that’s what counts. And if anyone ever said things about our friends that resemble what we have said about ourselves, most of us would likely get pretty vocal about defending our friends.

And so it is with our horses. Our emotional connection to our horse often blinds us to his or her extra “fluffiness” – and a plague on anyone who dares suggest our Fluffy needs to shed a few pounds!

The best way to steer clear of family feuds around your horse’s waistline is to apply a simple set of objective rules when assessing Fluffy’s body condition. Feeding to body condition is a strategy that celebrates the individuality of our horses. It recognizes that no two horses are the same and the “rules” for feeding are loose guidelines that undergo fairly rigorous refinement in the feed room.

There are two scales commonly used to assess body condition – Body Condition Scoring (BCS) goes from 0 to 5, and the Henneke Scale scoring system ranges from 1 to 9. A key similarity between these scales is that they assess the amount of fat on a horse. This is important because it accounts for the fact that fat is deposited preferentially on different parts of the skeleton. For example, a severely malnourished horse will, when weaned onto a healthy diet, deposit fat first along the lumbar spine. The very last place fat is stored on a horse is over the ribs. So, in most cases the ribs are the telltale landmark of how well-conditioned the horse is. For a healthy body condition ribs should not be visible, but should be felt when you run your hand along the horse’s side. There should be some fat around the tail head, and the withers should be rounded, with the shoulders and neck blending smoothly into the rest of the body. The ideal body condition is somewhere near the middle in both the 0 to 5 and the 1 to 9 scale, but it will vary with individual horses. Some horses will never achieve the ideal body condition, preferring either to hover around thin-ish or plump-ish.

This horse is fit and in a healthy body condition. His ribs are not visible, but can be easily felt. There is some fat around the tail head, withers are rounded, and shoulders and neck blend smoothly into the rest of his body. Photo: Canstock/Melory

Regulating feed intake

One of the key factors in maintaining a healthy body condition in your horse is the amount of food your horse actually eats. Let’s face it, some horses left to their own devices will literally pig out. But for others, it doesn’t matter how much expensive high-fat grain you offer, they’ll just pick like sparrows and look suspiciously like they need a daily cheeseburger with fries.

Feeding behaviour is regulated, at least in part, by a hormone called ghrelin. In horses this hormone is produced more or less consistently throughout the day, with larger amounts being produced at night. It contributes to horses’ trickle-feeding behaviour, wherein they prefer to eat small amounts frequently throughout the course of the day. And many of us who offer hay to horses 24/7 can attest to the fact that horses eat considerably more at night than during the day. When we impose “meal feeding” on horses, ghrelin gets produced in larger amounts during times of feed restriction. This can contribute to horses bolting their feed at mealtime and may predispose them to choke or colic.

As the main component of the horse’s diet, hay should be the basis of a complete ration. If you suspect your horse is not getting enough nutrients from his diet, have your hay analysed and then balance the ration with concentrates. Photo: Shutterstock/Zhuralev Andrey

Related: How to Interpret Your Hay Test

Why is my horse too skinny?

Conscientious horse owners frequently turn to the published National Research Council guidelines for feeding horses. But all too frequently, despite the ration being optimized for a horse’s weight, age, and workload, the horse still carries a low body condition score. This can be because the horse isn’t eating enough, or the horse is not able to extract energy from his diet, or the diet isn’t offering the nutrients the horse needs.

The horse that stays thin no matter how much or how often he is fed may not be getting enough nutrients from his diet, or he may have an underlying health condition. Photo: JD Lamb/Flickr

In cases where the horse isn’t eating the feed offered, this may be attributed to poor dentition (teeth should be floated at least once a year), stress (the stress hormone cortisol reduces production of ghrelin, thus inhibiting the drive to eat), or ulcers. Horses can be encouraged to eat more over the course of a day by providing smaller, more frequent meals. This is consistent with the way horses are hardwired to feed and can actually encourage them to eat more by avoiding big variations in ghrelin production. It can also reduce stress by eliminating fasting between meals. And gastric ulcers can be dramatically reduced because the stomach is not left empty for long periods of time.

If your horse stays skinny irrespective of how much or how frequently you feed, this can be an indication of not getting enough nutrients from the diet. Sometimes this can be fixed simply by conducting a nutrient analysis of the hay, then balancing the ration with concentrates. Hay is the mainstay of a horse’s diet and should always be considered the starting point for any complete ration. Other things to consider might be parasite burden (a simple inexpensive fecal analysis can tell you if the horse has an unhealthy parasite load), or gastric ulcers (which inhibit the ability of the gastrointestinal tract to digest and absorb nutrients). And again, increasing the frequency of feeding will often increase the total amount of nutrients consumed over the course of a day and can help put weight on a hard keeper.

This severely undernourished horse was assessed at a body score of 1 on the Henneke scale. He has no fatty tissue, and his vertebrae, ribs, tail head, and the bones of his withers, shoulder and neck are visible. When the emaciated horse begins to gain weight, fat will be deposited first along the lumbar spine, and last over the ribs. Photo: Wikimedia Commons

Related: How to Safely Refeed the Malnourished Horse

Why is my horse too fat?

While it’s relatively easy for most of us to wag a disapproving finger at a skinny horse, we tend to be more forgiving of our excessively fluffy equine friends. But carrying too much weight can be even less healthy for a horse than carrying insufficient weight. Health conditions that plague overweight people, including arthritis, insulin resistance, heart disease and circulatory problems, are equally prevalent in overweight horses. Insulin resistance has reached almost epidemic proportions in pleasure horses, and is frequently associated with obesity and laminitis. Insulin sensitivity and glucose metabolism are involved in the complex endocrine regulation of feeding behaviour. In its most simple explanation, insulin resistance decreases activity of enzymes that degrade ghrelin; thus ghrelin remains high in the blood and the stimulus to eat prevails. Controlling insulin resistance can be very challenging for horse owners as there is little in terms of a cure that we can rely on. Feeding compounds that can increase insulin sensitivity (e.g. fenugreek and cinnamon) can help control irregularity in plasma ghrelin.

“Fluffy” gains weight almost by looking at food. Being overweight is less healthy for a horse than being underweight, and carries numerous health problems. Photo: Dreamstime/Nigel Baker

Feeding a fat horse can be very difficult as often this horse will put on 20 pounds just by looking at a bale of hay. The key is to reduce energy intake without sacrificing nutrient intake. This can be achieved by feeding hay that has been soaked for 24 hours to reduce sugar content, and offering this in small amounts frequently over the course of a day. The diet can then be balanced with a ration balancer, which contains balanced nutrients without additional energy. Just providing a balanced ration can be enough to reduce excessive feed intake in overweight horses.

Feeding to body condition score is an excellent strategy to maintain a healthy body weight in horses. It recognizes the fact that all horses are individuals and must therefore be offered a diet that meets their unique needs. Your horse will thank you for it.

Related: Fruits for the Insulin Resistant Horse

Related: The Dangers of Equine Obesity

More by Wendy Pearson

Main photo: Canstock/Steing