Centaur infection

One Day, the lab you worked at had created a special type of carrots, meant to increase the life duration of cows, horses, etc. But your ex-coworker Kai, whom recently got you fired, showed up at your door with the carrots, forcing you to eat them before he left. or, tried to leave anyways. you turned into a busty Centaur with your mind only focused on creating more centaurs. slowly over a few weeks, the infection had spread to over half the human population, with whatever was left of uninfected humanity going into hiding.