There are many beneficial uses of hydrotherapy (the use of water to treat illness or pain) in horses. Water is frequently used to bathe and cool overheated horses, or applied to swollen or inflamed areas. Application of slightly pressurized water can help physically remove debris and promote drainage from a new wound.
However, due to water’s relative lack of electrolytes in comparison to body fluids and cells, there is a tendency for delicate healing cells that are bathed in water to absorb water, swell and possibly rupture. This is the reason that isotonic saline is preferred over water for bathing sensitive or new wounds, and why sterile saline solutions (rather than water) are used to flush the eye or used in surgery to bathe and flush abdominal organs.
That said, the use of water under pressure is a basic tool and one that horses should be taught to accept readily. As with many things, there is an art to teaching a resistant horse to accept being sprayed with a hose.
Apply a halter and leadrope to the horse. Stand on the left side of the horse at the shoulder and facing toward their rear end.
Turn on the hose at low pressure, pointed away from the horse. Then gradually move the stream of water toward the horse. Start by slowly running a gentle stream of water on the left shoulder and elbow area. Gradually move the water stream toward the area of concern, keeping water contact with the horse the whole time.
If the horse moves away, apply pressure on the face with the halter and SIMULTANEOUSLY keep water flow right on the same area. If the horse does not resist, stop the water stream every 10 seconds or so, and reassure them with voice and a gentle pat, then gently restart the water.
Many horses not only tolerate, but learn to enjoy cold water hosing.
Tips for safety & Success
It is best to practice this skill on your horse before you need to use it.
Apply a moderate amount of water pressure to an area. Horses usually tolerate pressure quite well, provided it is not excessive or directed on a newly injured or wounded area. Warm water hosing is helpful in treating chronically inflamed areas. For new wounds, use cold water.
Consult with your vet before you hose a wound that might be surgically repaired.