Returning healthy, fixed cats to their territories leads to a decrease in the infectious disease rate among these cats as they no longer transmit diseases sexually or from mother to kitten at birth, and they are less likely to transmit diseases through bites. Many infectious diseases in cats are acquired due to being housed around other cats, so minimizing the amount of time they spend in the shelter will decrease the rate of diseases in the population. As the outdoor cat population declines, there is a smaller chance that outdoor cats will be hit by cars or injured in other ways.
