The physical examination of the sexual and generative organs is made in large part through the rectum, and this portion of the examination should be carried out by a veterinarian only. By this means it is possible to discover or locate cysts of the kidneys, urinary calculi in the ureters, bladder, or upper urethra, malformations, and acute inflammations accompanied by pain. The external genital organs are swollen, discolored, or show a discharge as a result of local disease or from disease higher in the tract. The manner of urinating is sometimes of considerable diagnostic importance. Painful urination is shown by frequent attempts, during which but a small quantity of urine is passed; by groaning, by constrained attitude, etc. This condition comes from inflammation of the bladder or urethra, urinary calculi (stones of the bladder or urethra), hemorrhage, tumors, bruises, etc. The urine is retained from spasms of the muscle at the neck of the bladder, from calculi, inflammatory growths, tumors, and paralysis of the bladder. The urine dribbles without control when the neck of the bladder is weakened or paralyzed. This condition is seen after the bladder is weakened from long-continued retention and where there is a partial paralysis of the hind quarters. Horses usually void urine five to seven times a day, and pass from 4 to 7 quarts. Disease may be shown by increase in the number of voidings or of the quantity. Frequent urination indicates an irritable or painful condition of the bladder or urethra or that the quantity is excessive. In one form of chronic inflammation of the kidneys (interstitial nephritis) and in polyuria the quantity may be increased to 20 or 30 quarts daily. Diminution in the quantity of urine comes from profuse sweating, diarrhea, high fever, weak heart, diseased and nonsecreting kidneys, or an obstruction to the flow. The urine of the healthy horse is a pale or at times a slightly reddish yellow. The color is less intense when the quantity is large, and is more intense when the quantity is diminished. Dark-brown urine is seen in azoturia and in severe acute muscular rheumatism. A brownish-green color is seen in jaundice. Red color indicates admixture of blood from a bleeding point at some part of the urinary tract, usually in the kidneys. The urine of the healthy horse is not clear and transparent. It contains mucus, which causes it to be slightly thick and stringy, and a certain amount of undissolved carbonates, causing it to be cloudy. A sediment collects when the urine is allowed to stand. The urine of the horse is normally alkaline. If it becomes acid the bodies in suspension are dissolved and the urine is made clear. The urine may be unusually cloudy from the addition of abnormal constituents, but to determine their character a chemical or microscopic examination is necessary. Red or reddish flakes or clumps in the urine are always abnormal, and denote a hemorrhage or suppuration in the urinary tract.