Brucellosis disease primarily affects female animals by causing what issue?

Brucellosis is a contagious disease caused by bacteria of the genus Brucella, and it primarily affects female animals, notably in cattle, goats, sheep, and dogs. One of the most significant impacts of brucellosis in female animals is its association with abortions. Infected females may experience spontaneous abortions, usually around the fifth month of gestation. This occurs because the bacteria infect the reproductive tissues, leading to inflammation and ultimately causing the fetus to be expelled from the uterus.

This issue not only affects the health of individual animals but also has substantial implications for livestock production as it can hinder reproductive success, thereby impacting herd stability and economic viability for farmers. While brucellosis can lead to other issues such as infertility and decreased milk production, the critical and immediate impact of the disease is most prominently recognized in relation to causing abortions, making this the most appropriate answer.