Sheaths also swell as a result of being dirty.. Horses with large beans (accumulations of secretions at the end of the penis) and large accumulations of sheath smegma (normal pasty secretion) often swell. Horses that urinate into their sheaths tend to have dirtier sheaths and more problems with swelling.
Some people think Alaska has less sunlight than other places. The opposite is true. Averaged over an entire year, Alaska gets 10-17 minutes more daylight per day than the rest of the country. If you include civil twilight, Alaska gets 40 minutes more light on average than the rest of the country.
The earth gains between 10 and 1,000 tons of mass in the form of dust each day. On average, only two meteors about the size of an open hand hit the earth each day. With that figure, you would think the earth would gain so much mass over hundreds of millions of years it would eventually spin out of the solar system.