Horses are herd animals and an isolated, lonely horse is at greater risk of colic and other health problems. The horse herd provides security, status, emotional support and entertainment. Without a pasture mate, many horses get lonely.
She may pace the fence lines and cry or whinny when stalled. She'll be stressed and may develop ulcers. Signs of stomach ulcers include loss of appetite, dull coat, behavioral problems and biting or kicking during girthing.
What to do? Consider a pasture mate. There are a lot of adoptable horses out there. Not all are ride-ready but most will make great companions for your solo horse. You'll be doing both horses a favor!
Horses like to hang out with horses, but they enjoy the companionship of lots of different quadripeds. Donkeys, goats and llamas often make great pasture mates. And they generally require less upkeep than a horse.
There are some medical and herbal options available for the stressed, lonely horse. Consult a qualified professional before beginning any type of medicinal or herbal therapy on your horse.
Isolation is not natural to your horse. It's ok for a short time, but your horse will not thrive if kept alone.