TROCAR AND CANNULA.

New Zealand Mail, Issue 1726, 29 March 1905, Page 64

TROCAR AND CANNULA.

A simple and useful instrument is the trocar and cannula, used in tapping horses, sheep, or cattle Avhen isolated from the formation of gases due to acute indigestion. As avill be seen, the cannula is a metallic cylinder or tube Avith the rim at one end bent outward Avith a sort of flange, Avhich opposes the handle of the trocar. Into this cylinder or cannula is received the trocar, which, Avhen in place, should exactly fit top Avith the sharp-pointed end protruding beyond the end of the cannula. In this Avay together the instrument is to be driven within the distended flank of the suffering animal, nearly to the flange or guard, the cannula held there firmly by the thumb and forefinger, and the trocar removed, thus alloAving the escape of gas. There is almost no danger in the use of this instrument on cattle or sheep, and very little danger with horses. With cattle and sheep bloat is the distension of the rumen or paunch, and

the trocar should therefore be used on the left side, about lialf-way between the point of th© hip and the last rib. In the horse the distension takes place in the large intestine, and appears on the right side instead of the left, and the puncture should therefore be made on

the right side, and in the same relative location as in cattle or sheep. This little instrument will be found invaluable iu an emergency. Like the revolver once was in Texas, “you won’t need it all the time, but when you do you’ll need it migiity bad.” When not in use, both trocar and cannula should be kept clean, and should be smeared with gasoline to prevent rusting.— “Breeders’ Gazette,”