Forget blooming flowers and robins. One of the surest signs of spring around a barn is horsehair—and lots of it. By now your horses are probably actively shedding, leaving a layer of hair in the aisle, on your clothes and inside your truck. Shedding is more than just a nuisance, though. It’s a complex physiological process that tells you a lot about your horse’s health.

Shedding is not triggered by temperature. It’s linked to photoperiods: As the hours of daylight increase, a horse’s winter coat begins to loosen and shed. This process started way back in late December, but you usually won’t see the obvious, hairy results until now. 

Some horses hang on to their coats longer than others, but an individual’s shedding “schedule” will typically be consistent from year to year. Along the same lines, some horses shed out in a particular pattern each year, losing hair from their necks first, for instance, then along their flanks. This can lead to a very unsightly “patchy” period but isn’t cause for concern.

Click here to learn how myths about coat color have been proven false.

It is worrisome, however, if a horse isn’t shedding out as he usually would. If your normally punctual shedder is holding on to his coat longer than usual this year, it could be a sign of Cushing’s disease, particularly if he is older. Horses with Cushing’s also tend to shed the long “cat hairs” under their bellies and chins last, so the sudden appearance of that pattern is also cause for concern. 

Horses with Cushing’s disease are more likely to develop laminitis, so let your veterinarian know right away if your horse isn’t shedding normally. The sooner you have a diagnosis and can begin treatment, the better.

Don’t miss out! With the free weekly EQUUS newsletter, you’ll get the latest horse health information delivered right to your in basket! If you’re not already receiving the EQUUS newsletter, click here to sign up. It’s *free*!

This article first appeared in EQUUS issue #439.