Veterinarians often use "depression" as an indicator that a horse isn't feeling well. An owner familiar with a horse's usual attitude and responses can easily detect when he appears "off." It may manifest as a reluctance or unwillingness to work, a lack of enthusiasm for his favorite meal or a change in body language. Your horse may be communicating that he is unhappy about his job, his living quarters or the absence of a friend, but it also can signify something serious. Report any unusual behaviors or attitude changes to your vet so you can unravel the source of your horse's depression.
A Sign of Illness or Pain
The American Association of Equine Practitioners lists depression as a common denominator in many illnesses. Familiarize yourself with your horse's typical behaviors and attitudes so any changes are noted quickly.
If your horse appears depressed but is not running a fever and is eating normally, look for other causes; check for swelling on his legs or the beginnings of an abscess on his feet. Use a hoof tester to note any sensitivities on the bottom of his hoof. Think of any recent procedures he may have had, such as vaccinations. Some can cause soreness, and other negative reactions so check the vaccination sites for sensitivities, warmth and tightness. If the depression doesn't abate, your veterinarian may do a thorough exam, including a blood profile -- depressed horses have lower levels of cortisol than nondepressed horses.
If your horse appears depressed but is not running a fever and is eating normally, look for other causes.
Other Causes of Depression
Depression in horses is similar to that in humans, and can result from common sources: In addition to pain or illness, horses can be depressed due to anxiety and stress. Horses who don't like to jump, for example, may appear depressed when their riders appear, or when they are at horse shows. Horses experiencing a great deal of stress may develop an illness, such as colic or ulcers, which can lead to pain and depression. A horse also can become depressed from the loss of a pasture mate or companion.
Understanding a horse's body language will help you detect depression, especially with a new horse who you don't know well. If your horse is standing with his hind end to a stall door or gate, with his head in the corner, consider it a sign. His ears may be drooping to the side, which can indicate he is in pain. A horse who typically greets a person at his stall door or gate will display a lack of interest when he is depressed and will not attempt to make eye contact with either humans or other animals. Instead, his eyes appear to look at nothing. This changes, however, if something strange and unusual occurs in his vicinity. He may react more violently and appear to be more sensitive to a sudden event, such as a loose animal.
Treating the Depressed Horse
Remove any known sources of pain. Your vet can prescribe a pain reliever while your horse is healing from an injury to ease depression caused by pain. Ask your veterinarian about a calming supplement to help stress and anxiety at shows. If your horse doesn't improve, you may need to stop showing. Some horses perk up when going on a trail ride versus being ridden in the arena. See if your horse's mood improves when he doesn't jump one day, compared to the next. Change his living quarters; some horses are happier with 24/7 turnout, while others like to be stalled at night. When he's in his herd environment, note the herd behavior around him. If he has one equine friend he likes to be near, try putting them next to one another in stalls at night. If other horses are aggressive with him and run him off food or water, put him with another group.
If changes in living quarters and daily routines don't help, try dietary changes. Increasing forage, adding alfalfa hay and reducing or removing grain may help. Talk to your vet about testing for allergies as part of his dietary makeover.
Horses are herd animals and typically do better in social environments with other horses.