Solutions For The Skinny Horse

It’s more than throwing more feed at him.

Some horses can’t maintain a healthy amount of flesh, and it’s frustrating. Giving these horses more to eat is necessary, but it’s not that simple. First, make sure there isn’t an underlying problem. Be sure to check for:

1. Dental and mouth problems. The most common reason for weight loss is poor teeth. Watch for wasted forage around the feeder or feed dropping from the horse’s mouth while he’s eating. Nasal discharge, foul-smelling breath and swelling around the face may also indicate the horse’s teeth or gums need attention. 

First, rule out potential problems, like dental issues.

2. Worms. Inadequate internal parasite control can lead to weight loss. Taking a fecal sample to your vet for an egg count drug recommendation to target specific parasites is wise but not always practical. If this isn’t your cup of tea, then choose a broad-spectrum drug, like ivermectin or moxidectin, and deworm your horse. 

3. Disease. Illnesses can go unnoticed in the early stages, especially when you see the horse every day. Always involve your veterinarian initially in weight-loss problems. In addition to an exam, expect him to do blood tests, like a CBC (complete blood count) and liver enzymes. 

The Basics. Hay and grass are equine dietary staples. Offer hay free-choice 24/7.

Maximize grass hay, but consider alfalfa, too. Alfalfa complements grass by providing amino acids, the building blocks of protein. It can be fed as hay, cubes or pellets (be sure to moisten the cubes or pellets to prevent choke).

 Approximately 30 to 40 percent of the total hay ration can be fed as alfalfa, but avoid feeding more than 50% to prevent enteroliths. 

Concentrated feeds add calories, but don’t automatically reach for oats or sweet feed. Both are high in carbohydrates but not calories. Instead, consider feeding fat sources, as fat has more than twice the calories of carbohydrates. If you feed a commercially fortified feed, check the label for one that offers a high amount of fat—at least 8%. Good sources to see on the ingredients label are alfalfa meal, beet pulp, soybean meal, rice bran and ground flaxseeds without added cereal grains and molasses. 

You can also easily supplement fat, if you don’t want to disrupt your choice of a grain/concentrate. Choices include soybean oil, corn oil, flaxseed (ground or oil), rice bran and its oil, chia seeds, and hemp seed oil. While all contain the same 9 kilocalories per gram, they vary in fatty acid content, and that’s important to your horse’s overall health.

The goal is to simulate the types of fatty acids found in living grasses: a ratio of 4:1 of alpha-linolenic acid (an omega 3) to linoleic acid (an omega 6). Unfortunately, commercial feeds usually include soybean and corn oils, which are high in omega 6s. Therefore, to maintain the optimal balance, we like to add ground flaxseed or chia seeds, which are excellent sources of omega 3 and provide high-quality protein. 

Chances are you can purchase flaxseeds from your feed dealer and grind them yourself. However, most of us find ground stabilized flaxseed a much simpler choice. Many supplements are flaxseed-based, but if you want to add pure flaxseed to your horse’s diet to increase his fat, we like the flaxseed from HorseTech (, 800-831-3309) and OmegaFields (, 877-663-4203). Note of caution on OmegaFields’ OmegaShine: It does contain a small amount of oats, so may not be a good choice for insulin-resistant horses. HorseTech also carries chia seeds.
If yet more fat is needed, consider adding rice bran, or olive, canola, or rice bran oils, since they’re highest in the monounsaturated fatty acid known as oleic acid (an omega 9), which does not promote inflammation in the body.
Oils are heavy products to ship, so it may be wise to purchase them locally, if you can. We found good choices from: MannaPro (, 800-690-9908), Kauffman’s (, 800-332-5244), McCauley’s (, 800-222-8635), Triple Crown (, 800-451-9916), and AniMed (, 859-737-3441). We also like the oil form of Equi-Omega (, 800-248-0330), which is a good mix. 
All oils contain a combination of different types of fatty acids, but some are higher in one type over another. The table below compares commonly fed oils. 
How much fat? When adding oil, start with only one tablespoon per meal. You can slowly build up to one cup (240 ml) per day for the maintenance horse and as high as two cups per day for the intensely exercised horse. However, many horses don’t like oily feed, so take your time and prepare to back off if necessary. When feeding ground flaxseed or chia seeds, build up to ½ cup (120 ml) per day per 400 lbs. (180 kg) of desired body weight (a 1,200-lb. horse would work up to 1½ cups of ground flaxseed). 

The best commercial product for weight gain probably isn’t going to be cheap. In reviewing various products specifically marketed for weight gain, we felt that the manufacturer’s goal was often to make the product inexpensive and easy to handle and store. So, we eliminated any from our choices that didn’t meet our minimum requirements: 

Kauffman’s Coat, Skin and Weight is our top commercial choice.

1. The fatty acid composition of the fat source should be common to what horses would naturally eat. Therefore, no hydrogenated oils or fats high in saturated fat.
2. To ensure a balance of fatty acids, the product should contain a mixture of fat sources. 

For us, the fat source is critical. Most supplements designed to promote weight gain will either be high in fat, pre/probiotics, or a combination of these. The term “vegetable fat” on the ingredient label means the fat is plant-based, and some companies purposely use that term to protect proprietary information, which is understandable.

If you’re concerned about exactly what plants are being used, call the company and ask. Most will answer honestly, as they want what’s best for your horse. If they refuse to answer or don’t know, you may want to rethink the purchase.
There’s nothing wrong with soybean, corn, wheat germ, hemp seed, safflower or sunflower oils being included, even though they’re mostly omega 6s, as long as there are omega 3s to balance them. However, we’d avoid hydrogenated, saturated and trans fats. 

Digestive enzymes and protein are worthwhile supplement ingredients to aid digestion. Digestive enzymes can be recognized by the “ase” suffix at the end of the word (e.g., protease, amylase, lipase, etc.). 

Products designed to build muscle are good for the underweight horse. They often contain high protein ingredients (e.g., soybean meal, alfalfa, whey), branched chain amino acids, or the naturally occurring anabolic steroid gamma oryzanol. These products enhance muscle development during physical exertion, but they won’t have any effect when given to a sedentary horse so may not be worth your while for less active horses. See Products Chart.

Bottom Line. Underweight is not a normal condition, so rule out health problems first, and then feed a nutritious diet. Remember to adjust your horse’s diet slowly. It takes a few weeks for a horse’s system to adjust to extra fat, so be patient. 

Be sure to:
• Feed ground flaxseeds and/or chia seeds. These fatty feeds are balanced with omega 3s and 6s.
• Add oil for calories. 
• Choose a good pro/prebiotic.
• Mix protein sources to provide a large amino acid pool. 
Our favorite commercial supplement is Kauffman’s Coat, Skin and Weight because of its high omega 3s, high protein, and high microbial count.

Probiotics May Help . . . 
. . . especially if the horse is somehow under stress, whether due to age, illness or activity.

You can feed the best forage available and your horse won’t get its maximum benefits if his digestive enzymes aren’t up to snuff. Normally, billions of beneficial bacteria work in the digestive tract to produce enzymes needed for digestion. If their numbers diminish, then digestion isn’t optimal. If the horse has trouble holding his weight, battles an illness (especially if antibiotics are used), is under stress (like shipping or stall confinement) or is experiencing diarrhea, a probiotic might help. 

A prebiotic is different than a probiotic because the prebiotic doesn’t contain any live microbes. Instead, a prebiotic feeds and strengthens the existing bacterial flora. The result is weight gain, since the horse gets more calories from what he eats. Prebiotics are listed as “fermentation products,” derived when bacteria ferment various carbohydrate sources. Ration Plus (, 800-728-4667) is a good prebiotic choice.

A probiotic consists of live microbes and replaces the beneficial bacteria destroyed by stress, pasture restriction, or antibiotic therapy. Cultures of live yeast organisms are also used as probiotics. Yeast benefits the horse by stimulating the growth of fiber-digesting bacteria. The most common strain of yeast fed as a probiotic is Saccharomyces cerevisiea. 

Probiotics also help promote the formation of B vitamins, which stimulate the appetite, protect the digestive tract lining, and synthesize body protein (e.g., muscle, red blood cells, enzymes, antibodies and specific body tissues). Not enough B vitamins can result in weight loss due to malnutrition at the cellular level. 

When shopping, check the number of colony forming units (CFUs), which tells you the number of microorganisms. There should be at least one billion (denoted by 109) CFUs per organism. More is preferable. If the product shows 106, 107 or 108, we don’t consider it concentrated enough for a significant benefit. Yeast+ from Horse Tech (, 800-831-3309) contains a high number of yeast organisms.

Article by Contributing Nutrition Editor Juliet Getty, Ph.D.

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