Hatha yoga is a moderately-paced, catch-all name for the vast menu of poses that are practiced wherever you can roll out a sticky mat.
An 1100 lb horse on a dry forage diet at an average temperature of 68 degrees Fahrenheit will need a minimum of 6-7 gallons of water per day or 48-56 lbs of water, and many horses will drink more water than the minimum.
In the hot weather the horse ought to b drinking 10 to 20 gallons a day. However he needs to be checked by keeping him in a stall and keeping track of his real water intake. As with humans high water intake can be a sign of other problems.