Q: This time of year, my horse’s mane and tail get very dry, and even his coat seems dry. I use coat conditioners when I bathe him, but I’m wondering what I could do nutritionally that might help?

A: If you live in a hot, dry climate, preventing a dry mane and tail and coat can be challenging. I find this to be especially true of horses living in dry lots or with dirt runs where they are basically rolling in dust.

Other than using topical products to try to maintain coat quality, the best you can do is to give the horse’s skin and coat a fighting chance by ensuring you’re feeding all the building blocks needed to maintain skin and coat health.

Minerals

Key nutritional players in this arena are zinc, copper, fatty acids, and biotin. Zinc is vitally important to a number of enzymes in skin. Epithelial cells that make up skin require zinc for reproduction, maintenance, and repair. Additionally the synthesis of keratins (proteins that protect epithelial cells and that are found in hair) and other associated proteins rely on zinc for proper function. While zinc is found in forages, the amounts present might not meet your horse’s needs.

Copper is generally in even shorter supply in forages than zinc. Copper is necessary for the enzyme lysyl oxidase, which in turn is required to maintain the structural integrity of the cross-linkages that provide strength to collagen in the skin.

Together copper and zinc impact melanin, the protein responsible for hair pigmentation. Therefore, inadequate copper and zinc status might not only impact the keratinization of hair but also its color. Hair is at greater risk of oxidative damage if melanin is inadequate.

If you’re just feeding forage, consider adding a source of copper and zinc that provides about half of the National Research Council’s daily requirement, which for a 1,100-pound horse is 50 milligrams of copper and 200 milligrams of zinc. My preferred method is using one of the quality ration balancing feeds and supplements available on the market because they also supply other essential nutrients that might be missing in a forage-based diet.

If you’re already feeding a commercial feed, make sure that you’re following the feeding directions and offering adequate amounts, otherwise your horse might have deficiencies in nutrients key to coat quality.

Fat

The cell membrane layers that connect the cells that make up hair contain large amounts of fatty acids. The fat in the cuticle cells make them hydrophobic, meaning they don’t attract water. This acts to make them waterproof but also keeps moisture in. Cuticle cells should lie flat like shingles on a roof, but if they become damaged, they peel away from the hair allowing internal moisture to escape.

Therefore, ensuring adequate amounts of essential fatty acids in the diet might help improve coat quality. I particularly like sources of supplemental fats that provide more omega-3 fatty acids than omega-6, such as flax or camelina. For coat improvement purposes, I find plant-based sources to be more than adequate, and about 4 ounces of flax seed or 2 ounces of the oils should be enough for you to see an improvement in an average-sized horse.

Biotin

While we typically think of biotin in relation to hoof health, biotin also plays a role in skin and coat. Biotin is a B vitamin that is actually made by the bacteria in the horse’s hindgut making biotin deficiency unlikely.

However, in other species inadequate biotin results in poor quality skin and coat. This makes sense when you consider that biotin involved in fatty acid synthesis, amino acid metabolism, and a range of other metabolic pathways. While there are no guidelines for how much biotin to supplement to see improvement in coat quality, research suggests 20 to 30 milligrams for and average-sized horse to aid in hoof quality and we can assume similar levels are necessary to see coat improvements.

Take-Home Message

Ensuring that your horse has the building blocks necessary to create a healthy coat from the inside is your best way to defend against a dry coat. However, make sure that you are not shampooing your horse too frequently as this can remove naturally occurring oils. Additionally, look for simple shampoos that contain few detergents and avoid those with alcohol as these can strip the oils from a horse’s coat.