Are You Loving Your Horse to Death? Equine Obesity

Disclaimer: If your horse is overweight, please consult with your veterinarian and equine nutritionist about the best feeding program for weight loss. Depending on medical issues, that sometimes come with equine obesity, and/or level of activity, each horse will have a different weight loss journey.

Is my horse overweight?

By definition, a horse is considered overweight if they score between a 7-9 (a 9 being Obese) on the Body Condition Scale (BCS). Please see the earlier newsletter about Body Condition Scoring to learn how to properly score your horse.

You may also consider calculating an estimated weight for your horse. The University of Minnesota has a chart to calculate this based on breed/type, height and length of your horse.

My horse is overweight, now what?

For the overweight horse that doesn’t have any metabolic diseases the best way to gear up for a weight loss program is first identifying the “why”. Is it the amount of exercise your horse is receiving? Could it be the amount of feed and/or your horse is consuming? Understanding a ratio of input versus output will be beneficial in determining how to treat your horse over the course of the next 90 days.

Another thing we have to consider is the caloric input vs output. If you are feeding your horse too many calories that they are having a hard time burning, over time your horse will start to store adipose tissue, or fat. In most cases owners that see their horse everyday may not realize that their horse is gaining this adipose tissue until their horse has increased their BCS to beyond the ideal range. This issue can lead to other health concerns such as Equine Metabolic Syndrome (EMS), laminitis and hyperlipemia. Hyperlipemia is where the stored fat enters the bloodstream to be processed through the liver, but overloads the liver because there is so much.

*the scenario below is calculating calories utilizing techniques from a previous newsletter titled “Counting Calories”

Scenario 1: An 8 year old Warmblood mare in light work coming out of the “Off Season”. Owner noticed the mare had gained weight and is now at a BCS of a 7.0, weighing in at 1250lbs. Nothing changed in the mare’s diet however, she wasn’t in any work for two months. She’s out on pasture with a meal at noon of alfalfa hay, and on a performance feed “X” worth 1590Kcals fed at a rate of 10#/day.

1590 Kcal x 10 = 15900 from the grain                    15900 divided by 1000 = 15.9 Mcal

0.9 Mcals x 18.75# (1.5% BW in pasture) = 16.785 Mcal pasture consumed

2.2 Mcal from alfalfa meal *assuming the alfalfa meal is a flake of alfalfa hay*

15.9 + 16.785 + 2.2 = 34.975 Mcals

When this mare was at “maintenance” (no work) she was only needing 18.45 Mcals of energy a day. Once she got into light work she needed only slightly more energy at 23 Mcals a day.

The easy solution: A reduction in 11.975 Mcals of energy a day would result in weight loss if the current workload were to be maintained. However, if the workload were to be increased to “moderate work” the Mcals allowed would increase to 27.668 Mcals resulting in only a 7.307 Mcals reduction.

Option 1: Reduction of 11.975 MCals

Horse feed “X” has a minimum feeding recommendation of 9# based on light work for an average horse. Reducing the feed by 1# a day and also removing the noon time meal of alfalfa hay would result in the reduction of …Mcals.

1590 Kcal x 9 = 14310 Kcals grain              14310 divided by 1000 = 14.31 Mcals

14.31 + 16.785 = 31.095 Mcals

*We would still need to reduce the number of Mcals consumed*

Option 1a: Adding a muzzle to pasture time would reduce the amount of pasture consumed by roughly 30% (according to the University of Minnesota extension) Which would reduce the amount of Mcals consumed to 11.750.

14.31 + 11.750 = 26.06 Mcals of energy a day.

*It would still be higher than the energy required for this mare, but would allow for a safer weight loss program without too many changes and cutting out nutrients that she will need*


Option 2: Increasing the amount of work to moderate from light work.

This mare being in light work isn’t burning enough calories and would benefit from increasing in her workload to accommodate the number of calories consumed. In combination with a reduction in 

calories consumed. Adding days of long trotting for 30 minutes with proper warm up and cool down of at least 3-5 times a week (from maintenance and not light work) will create enough aerobic exercise for weight loss.

*It’s important to note that every horse is an individual and what works for one may not work for another. However, this basic model will create weight loss since it puts the horse in a caloric deficit while still maintaining the minimum amount of forage and vitamin & mineral intake. Horses are foragers and must consume hay, pasture or another source of fiber fairly constant throughout the day. Starvation will not produce the ideal weight loss outcome that will keep horses happy and healthy.


Scenario 2: A 28 year old Quarter Horse gelding that is out on pasture 24/7, retired from work and only has a salt lick. He has a BCS of a 6.5 and is arthritic so exercising isn’t an option at a frequency most horses could maintain.  

*this gelding is considered at maintenance and will only need 16.4 Mcal/day. The pasture he is on produces 16.785 Mcal/day.

So, what now?

Option 1: Utilizing a muzzle while grazing out in the pasture will reduce his intake by about 30% according to studies conducted by the University of Minnesota. There are plenty of options for muzzles on the market, and choosing the right one for your horse may take some trial and error. Thankfully there are great resources to help with this decision. Adding a multivitamin or ration balancer will benefit him by balancing out the pasture he is getting.

Option 2: Weighing the hay out in a slow feed hay net. This accomplishes two things. One, you know exactly how much hay your horse is being offered and can better track the caloric intake. Two, the slow feed hay net not only reduces the waste of hay but slows down the intake on average by 40%, allowing your horse the same amount of time to consume a lesser amount of hay. This ensures no behavioral changes in your horse’s mood while limiting forage intake, (meaning the likelihood they’ll become grumpy is less). Adding a multivitamin or ration balancer will benefit him by balancing out the pasture he is getting.

A byproduct of the slow feed hay net is blood insulin levels. In a study by the University of Minnesota, eight adult Quarter horses with an average body weight of 1,241 pounds and a body condition score (BCS) of 7.2, were fed in individual stalls and provided about 60 percent of their maintenance energy needs, split evenly between two meals (morning and afternoon). Horses were either fed on the floor or in hay nets and had their blood tested on days 0 and 28 every thirty minutes after feeding.

In this study they were able to look at the glucose, insulin, cortisol and leptin content with the results proving that horses fed in slow feed hay nets had lower peak insulin levels and cortisol levels. This is due to the longer period of consuming forage versus the horses that were fed on the floor.

Option 3: Both! Some horses can handle mentally having both options done at the same time, while other horses may see this as a “constraint” and will exhibit behavioral changes. It would be a trial and error to determine if your horse can maintain its mood while having both options added to their new routine.

With an overweight horse, there are of course several methods for weight loss. These two scenarios are purely to give some insight on options, however every weight loss program should be discussed and designed with a veterinarian and nutritionist. This isn’t a quick, short cut type of management and patience will be necessary in order to conduct this plan correctly. Majority of equine weight loss programs will take 90 days to shift 1-2 BCS, fully dependent on the horse and management style.


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