Worldwide, too little iodine in the diet is the most common cause of hypothyroidism. In countries with enough iodine in the diet, the most common cause of hypothyroidism is the autoimmune condition Hashimoto's thyroiditis.
The pronghorn is the second fastest land mammal in the world, after the cheetah. It can attain speeds of over 53 miles (86 kilometers) per hour. Size relative to a 6-ft (2-m) man: Fleet-footed pronghorns are among the speediest animals in North America. They can run at more than 53 miles (86 kilometers) an hour, leaving pursuing coyotes and bobcats in the dust.
Horses that are bred for speed, like Quarter Horses and Thoroughbreds, can reach 40 mph for short periods of time. I would say the average fro horses overall is about 33-35 mp â¦ h...it really depends on the horse. I've seen Thoroughbreds only get to 20 and I've ridden my Paint up to about 43.orses speed varies with their stride length, body build, and other factors, but here is a basic idea of how fast-- in miles per hour-- horses move at their various gaits: Wal â¦ k: Roughly 3-4 MPH.