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.
Source(s): http://www.ultimatehorsesite.com/info/farandfast.h... Mar 2nd, 2011 at 3:51 AM Reply. ginefer 0 20 to 30 mph the top speed is 40 mph. Answers. How far and fast a horse runs in one day really depends on the condition and breed of horse, as well as the terrain and weather conditions.That being said it is possible for some horses to travel as far as 60 miles or more in a day, but a more average distance is around 20-30 miles a day.ource(s): http://www.ultimatehorsesite.com/info/farandfast.h... Mar 2nd, 2011 at 3:51 AM Reply. ginefer 0 20 to 30 mph the top speed is 40 mph. Answers. How far and fast a horse runs in one day really depends on the condition and breed of horse, as well as the terrain and weather conditions.