A practical method of reducing spread of disease by hypodermic needles

Transmission of infection between animals is possible when using multidose syringes. The possibility of infection spreading can be reduced by using a telescopic device which fits the syringe barrel and is topped by a cap containing plastic foam impregnated with biocide. Under laboratory conditions, and continually contaminating the needle with various bacteria, infection could not be cultured in broth until after at least 25 injections and in most cases contamination did not occur after 50 injections. When culture was undertaken on solid media breakdowns occurred more frequently, possibly because the agar became lodged in the needle and shielded the bacteria from the biocide.