Quick Reads: Magical Latherin!

Photo courtesy of Amanda McCoy: Dewey, a four-year-old Quarter Horse, displays a healthy lather, evidence of her body’s natural cooling system at work.

Quick Reads: Magical Latherin!

By Désirée Braganza, EdD, EBQ

Here’s a general explainer on horse sweat. It doesn’t apply to horses with metabolic issues or those in intensive sports like endurance. And as always, if a horse (or human) shows signs of overheating or heat exhaustion, that’s a veterinary or medical concern. Cooling measures and professional care come first.

Sticky, sweaty days are upon us and our horses are right there with us. Or, if you’re south of the equator, you may be exercising with winter gusto. Either way, though we share mammal status, human sweat and horse sweat are very different.

Unlike us, horses don’t sweat just to cool, they sweat with a chemical twist. One protein in particular makes their sweat magical: latherin. This was explored in a 2013 study, The structure of latherin: a surfactant allergen protein from horse sweat and saliva. Though published over a decade ago, latherin remains a mystery scientists continue to probe. Here’s a quick glossary before you dive into the article:

Latherin: The protein in horse sweat. It’s what you see as foam when horses really work up a sweat.

Surfactant: Because horses have pelted hair, latherin breaks the surface of liquids so sweat can move along the hair shaft, evaporate, and cool the body.

Allergen: Some people and other species are allergic to latherin. This may give horses a protective edge.

Detergent: Latherin keeps coats clean. Oddly, it acts as an antimicrobial, killing harmful microorganisms but sparing the beneficial ones.

In saliva: Latherin also shows up in horse saliva. Why? Perhaps it transfers to the coat during self or social grooming.

Very few mammals produce latherin at all making it one of the traits that sets horses apart.

Everyday Tips

• Notice when and where your horse sweats and how it relates to temperature and conditions.

• Resist the urge to over-bathe. A bit of “dirty” may be doing your horse good.

• Choose bathing and grooming products carefully, whether natural or synthetic. Each horse’s skin and coat microbiome balance shifts with seasons, climate and environment.

• Pay attention to any sudden changes in your horse’s sweating pattern. Think of it as another vital sign that can potentially be an early indicator of pain or a functional imbalance.

A penny for your thoughts? Have you noticed your horse foaming up after exercise or staying clean in ways you can’t quite explain? We’d love to hear from you.

About the Author

Dr. Désirée Braganza received her equine behaviorist qualifications from the Natural Animal Centre, then located in the UK and South Africa. As a member of Bodhi Horse Practice, she collaborates with equine professionals worldwide on research projects specific to experiences of domesticated horses from an ethological lens. She is a horse partner, a rider, and has cared for and supported numerous horses over the years. Désirée recently relocated from Northern California and is now based in Athens, Georgia, USA. She consults internationally in-person and virtually.

Friendly Reminder: These articles are meant to spark thought, not replace expert guidance. Consult equine professionals for individual advice.