Your Comprehensive Guide for the “Skinny” on Underweight Horses

Equine Nutrition, Equine Care

Hay there horse owners!

We are in that chilly time of year when going to see our horses requires hand warmers, a good hat, and a reliable car heater. For those missing one of those toasty elements, you’re a braver woman than myself.

But the cold doesn’t keep us from seeing our favorite velvet noses. Equestrians are resilient, even in the worst of conditions. Not even the arctic blast stops us from being with our horses multiple times a week. But sometimes when we look at our horses every day, small changes in their conditions can take longer to notice. Then one day you remove their winter blanket and see your beloved horse has suddenly lost some weight. Your heart drops as you notice their topline declining, and you want to do everything to help them bounce back.

Horses can lose condition for a variety of reasons, and we want to help. Today at Equine Outfitters LLC, we are going to determine why horses can lose weight and how to bring them up the body scale. We prepared this comprehensive guide to give you the resources to make the best decision for your horse.

* Disclaimer: The purpose of this article is to provide general information, not diagnose or treat any conditions. Please consult your veterinarian with any health concerns about your horse.

Is My Horse Underweight or Lacking Muscle?

First, we need to determine if your horse is truly underweight, or just lacking muscle. For horses hovering along the edge, it can be tricky to differentiate between the two. Contrary to popular belief, horse body assessments aren’t a one size fit all anymore. Some horses can have a topline with ribs showing, whereas others have fat covering their bellies without any topline. New nutrition developments are defining the latter as topline deficiency syndrome.

To help clear the confusion, we’ve created a fantastic sheet to help you evaluate your horse’s topline and body condition. In the BCS/TES Evaluation Sheet, you can access our in-depth scoring system that will give you a clear picture of where your horse falls on the scale. After using this guide, you will better understand if your horse is needing supplemental calories, amino acids, or both.

Click here to unlock the BCS/TES Evaluation Sheet.

After taking a look at the BCS/TES Evaluation Sheet, you’ve decided that your horse’s weight really isn’t that bad. They’re on the leaner side, and while they have a layer of fat, you’re just not seeing them fill out along their topline. If your horse is affected by topline deficiency syndrome, we have a couple of options for you to try.


The first option is to try a good probiotic with digestive support. The one we highly recommend is the BioEZ Equine Digestive Optimizer. A healthy digestive and immune system will help your horse feel better and increase its ability to process nutrients. This supplement is fantastic for horses needing to improve body condition, loose stools, and even colic too.


Another helpful option is adding amino acids to your horse’s diet. Amino acids are the building blocks of protein which is responsible for building muscle. When horse’s are deficient in amino acids, it can become an uphill battle trying to increase their muscle mass. For horses needing more muscle mass, we cannot say enough good things about the Topline Advanced Support from Progressive Nutrition. This supplement targets the topline with advanced support to show quick muscle improvement. Along with the balanced amino acids, the topline support supplement also has rice bran to enhance muscle building, flaxseed for balanced omega fatty acids, along with other nutrients to support weight gain, stamina, and performance. If your horse is suffering from topline deficiency syndrome, we highly recommend trying the Progressive Nutrition Topline Advance Support.


How to Tell if Your Horse Is Underweight


Now that we’ve covered if your horse needs muscle as opposed to weight, let’s talk about the underweight horses. An underweight horse is one that doesn’t have enough fat and muscle to cover their body. Underweight horses normally have a combination of a thin neck, sunken withers and ribs showing, along with their spine and hip bones protruding.


To determine if your horse is underweight, there is a helpful tool called the body condition scale (also commonly referred to as the BCS.) The BCS has clear visual explanations on a scale of 1-9 to tell you where your horse falls on the scale. In the picture below, we have the horses segmented into categories of underweight, adequate, and overweight.


Why is My Horse Underweight?


Now that you’ve identified where your horse falls on the BCS/TES Evaluation Sheet, we need to identify why your horse is underweight. There are many factors as to why horses lose weight or have trouble gaining and trust me it’s not for a lack of trying. Sometimes there are factors that make it difficult for a horse to gain or maintain a healthy body weight. And honestly, identifying the exact reason can be half the battle. Below we will provide a list of factors that contribute to underweight horses.

Not Enough Calories

A common reason horses are underweight is that there simply aren’t enough digestible calories to support their workload. Some owners get lucky with easy keepers, but for the hard keepers maintaining weight can be a little more complicated. And because of this, we all know there isn’t a one size fits all approach to horse feed management. The mature quarter horse in moderate walk trail work will not have the same caloric demands as the young sport horse in an intense training program. A couple of ‘quick fixes’ for the hard keepers are adding more good quality forage to their diet, introducing or increasing their concentrated grain, or adding another source of fat like rice bran or oats to their diet.

Gastric Issues

Another common reason a horse is underweight is by having underlying gastric problems. Gastric issues can range from ulcers, a high parasite load, or even allergies to an element in their current diet. Differentiating gastric issues from others can be tricky, but there are a couple of common symptoms. Horses with gastric problems tend to have dull coats since their body doesn’t process nutrients properly. They can also have low energy levels, loose stools, can be moody and even colic. The best way to diagnose gastric problems is through a consultation with your veterinarian.

Weight Issues with Senior Horses

We love our senior horses! They give us so much love and wisdom. But as they age, senior horses tend to struggle with maintaining weight for a variety of reasons. Common problems with senior horses tend to show up in teeth issues, gastrointestinal problems, or immune dysfunction. These issues can be difficult to combat, but at Equine Outfitters LLC we would be happy to create a customized feed regimen for your senior horse.

Time of Year

In the cold winter months, horses use more calories to stay warm. It’s very common for horses to lose weight in the winter since they’re using more calories than in other seasons. A couple of ways to combat this is by blanketing to help preserve warmth, adding additional available hay, or upping their commercial grain intake.

How Do I Make My Horse Gain Weight?

Now that you understand where your horse falls on the BCS/TES Evaluation Sheet and potentially why they’re having trouble gaining weight, we can start making changes and additions to your horse’s diet.

Analyze Your Grain

Our first recommendation is to break out the scale and weigh your horse’s grain. Many horse owners would be shocked to realize they are underfeeding the recommended grain amount. The reason this is common is that people tend to feed by the number of scoops instead of weighing out the grain. If you’re guilty of this, no worries. We’ve all been there.

After weighing and confirming your current amount of grain, we suggest looking at the recommended amount from the supplier. Each supplier of commercial grain has a recommendation based on your horse’s weight, activity, daily intake of hay and NRC (National Research Council) requirements. You may find that to achieve your horse’s goal weight, you might be underfeeding according to the supplier’s recommendation. If this is the case, then slowly increasing to the recommended amount is a great first step to increasing your horse’s weight. Side note: feed your horse to the weight you want them to be, not their current underweight status.

Another option is to decide if your horse is getting the best grain. With so many grains on the market, it can make your head spin to pick the best one. At Equine Outfitters LLC we specialize in equine nutrition and would be happy to create a custom program for your horse. Click here to book a consultation.

Analyze Your Hay

Now that you know exactly how much grain your horse is getting, it’s time to look at their available forage. Hay comes in many types and forms, so knowing exactly what your horse is getting is critical to its diet. Are they getting hay in the form of round bales, flakes or soaked pellets? What type of forage are they receiving? Is your horse on just one type of forage or are they on multiple? What weight of forage is your horse receiving? These are all important questions to answer before moving forward with other options.

Pro Tip! Another element that is critical to a horse’s diet is to know the actual nutrient analysis of your hay. Forage can vary from regions, seasons, and many other factors. By running an analysis of your hay, it will give you a 100% accurate nutrient analysis breakdown. Then if your hay test comes back with a lower NSC or protein count, you already know that’s an area you can adjust.

Increase Horse’s Weight With More Forage

Once you’ve confirmed exactly how much grain and hay your horse receives, the next standard recommendation is to increase hay. Increasing hay is the most natural way to up your horse’s caloric intake.

On average horses require a minimum of 1.5-2% of their body weight in hay per day with a maximum consumption of 3% total food per day. Here’s an example: you feed you 1,000lb horse 20lbs of hay + 5lbs of concentrate per day but he still needs just a little more weight. You can still increase his hay by another 5lbs per day to maximize the 3% total food per day. When we decide just to increase their hay by a couple of pounds per day, that can be enough to increase caloric intake and increase weight. Granted this is a basic example, but it shows how increasing hay is a simple way to help horses gain weight. Side note: hay quality can play a big part here.

Besides just increasing hay, another option is to introduce a secondary type of hay. If you feel your horse needs additional protein, alfalfa is a wonderful option. Alfalfa is higher in calories than standard grass hay, which makes it a great addition if your goal is to increase weight and muscle. It also comes in the form of flakes, pellets, and cubes, making it easily accessible.

Another option for alternative forages is teff hay. Teff hay is great for horses that need to gain weight without increasing energy. It is also a great option for horses with metabolic problems that need lower NSC and higher fiber. Teff can be less palatable than other types of hay, so if you have a picky eater, it may take them a while to get used to the flavor of Teff.



Managing an underweight horse is not a small task, but we hope after reading this blog you have a better understanding of why horses can be underweight and how to help them. If you’re looking for more support, please feel free to schedule a nutrition consultation with us at Equine Outfitters LLC.