When do horses lose their summer coats?

Most of us are acutely aware what happens towards the end of winter when horses start to lose their coat as great tufts of it fall freely to the ground when grooming, stick to your eyelashes and get up your nose! But are many of us so know what happens with its summer coat? I suspect not.

The answer lies in understanding how a horse’s hair grows. It’s influenced primarily by the changing levels of daylight throughout the year. In early to midsummer, hair growth is dormant. This is technically known as the ‘telogen’ phase. As the amount of daily sunlight diminishes in late summer, the horse's hair starts growing. This is known as the ‘anagen’ phase. This phase continues until the full winter coat has grown. Through the winter nothing much changes until early spring, when increasing daylight triggers the new hair to grow as the old coat sheds out.

Horse with a Summer coat

The hairs of a horse’s summer coat are much shorter and thinner. They give a really healthy horse a sleek and shiny coat. These short, fine hairs protect your horse from overheating in the warmer weather. However even as early as the beginning of August in the UK, the hours or rather minutes of sunshine each day, gradually diminishes each day, little by little. To start with you certainly wouldn’t notice but by the time the harvest is taken in, you’d probably notice a change in your horse’s coat.

Occasionally warmer than normal temperatures slow or halt the growth of the winter coat but temperatures have to be significantly warmer and not just for a day! So prepare yourself for a woolly bear of a horse but from what we understand from the Long Range Weather Forecast, it looks like he’ll need it this year as, supposedly, it’s going to be a bad one but we’ll see.


Kim Horton

Co-Founder of EQUUS and a keen equestrian, when Kim's not at her desk she's with her horse, Waldo.


  • Shirley Hassen posted on October 15 2017 at 06:10 AM

    My 15 years old filly is losing her winter coat. Her hair is patchy, showing skin. She gets fed well, hay and bag food. I am told that she should not be patchy. Chrystal is not sick and this molting happens every year. Does she have a problem or is the patches normal.

Leave a comment