Inflammation of The Urethra (Urethritis, or Gleet).
This affection belongs quite as much to the generative organs, yet it can not be entirely overlooked in a treatise on urinary disorders. It may be induced by the same causes as cystitis (which see); by the passage and temporary arrest of small stones, or gravel; by the irritation caused by foreign bodies introduced from without; by blows on the penis by sticks, stones, or by the feet of a mare that kicks while being served; by an infecting inflammation contracted from a mare served in the first few days after parturition or one suffering from leucorrhea; by infecting matter introduced on a dirty catheter, or by the extension of inflammation from an irritated, bilocular cavity filled with hardened sebaceous matter, or from an uncleansed sheath.
Source: Diseases of the Horse