PARATYPHOID IS CARRIED BY MICE AND RATS AND SOME TIMES AN INFECTED BIRD WHICH CAN BE A CARRIER AND SHOW NO SIGNS. I HAVE PERSONAL EXPERIENCE OF THE LATTER WHICH WAS BIRDS I PURCHASED FOR STOCK.IF CAUGHT IN TIME BAYTRILL WILL WORK BUT THE BEST PRODUCT IF YOU CAN GET YOUR HANDS ON IT IS DE WEERDS PARA STOP.KEEP YOUR EYES OPEN FOR TRAILING WINGS AND SWOLLEN WING OR LEG JOINTS AS THESE ARE TELL TAIL SIGNS AND AT THIS POINT THE ONLY CURE IS THE BIG LOFT IN THE SKY