Q. I have an overweight pony I started on a weight-loss program recently. I know a good way to ensure I’m giving him the right amount of forage is to calculate the weight of the forage as a percentage of his body weight. Should I calculate this based on his current (overweight) body weight, or his ideal body weight?

A. It is excellent that you realized your pony should be on a weight-loss program. Ponies, even more so than horses, are often easy keepers, which means they metabolize feeds efficiently, making them prone to obesity and related health challenges. I would strongly encourage you to have your veterinarian evaluate your pony for potential metabolic issues to make sure you aren’t fighting a more complicated problem.

Calculating Equine Forage Intake

There are a couple trains of thought about weight reduction and how to calculate desired feed intake on a percent of body weight basis. The common thread running through all these methods is that reducing caloric intake is key to weight loss. I would recommend no matter what method you choose, you come up with a way to consistently and objectively evaluate your horse’s weight, be it pounds of body weight or inches (or both). Also consider how you can increase his calorie expenditure, or the amount of exercise he gets in a day. A combination of decreasing calorie intake and increasing calorie expenditure will produce the best results.

One common recommendation from nutritionists is to feed the horse or pony 1.5% of their current body weight in forage. The other is to feed him 2% of the desired body weight in forage. Since you did not give the type of pony or his current weight, I am going to show example calculations for a 14-hand Welsh pony that weighs 850 pounds with an ideal weight of 750 pounds. Using the 1.5% of current weight method, he should eat approximately 13 pounds of hay per day. Fed at 2% of desired body weight, he should eat 15 pounds of hay per day. You did not mention how much you currently feed, but I would caution against dropping the amount too quickly or drastically. Always feed at least 1.5% of the horse’s current weight, unless a veterinarian directs otherwise. Restricting forage too much can induce hyperlipidemia (an excess of lipids in the bloodstream), cause insulin resistance issues, and lead to stereotypies such as wood chewing.

Other Factors in Equine Weight Loss

Reducing the amount of forage offered per day will help your pony lose weight, but it’s also important to consider the type of hay you’re feeding. It should be a more mature grass hay with a neutral detergent fiber (NDF) level of between 50% and 65%. A measure of insoluble fiber, the higher the NDF, the fuller your horse will feel, decreasing his appetite (similar to when people trying to lose weight increase their fiber intake. Having your hay analyzed is the best way to determine the NDF content. Avoid immature grass hay and legume hays, because they usually contain more calories than your pony needs.

Also ensure your pony doesn’t consume his allotted hay too quickly. You can accomplish this by feeding flakes of hay every few hours or dividing the hay into multiple meals. You can also invest in a hay net with very small holes, or even put your hay in multiple nets, to make it more challenging for your pony to pull out the hay.

Take-Home Message

Adjusting the amount and type of hay your pony eats can help him lose weight efficiently and safely. Make sure to monitor your pony’s weight loss carefully. Once he reaches the desired weight you might need to increase his hay intake to help him maintain a healthy weight. Work closely with your veterinarian and an equine nutritionist to ensure your pony does not have any underlying health conditions, and confirm his diet meets his nutritional needs.