After two months of being human, Sally found she was loving being human. She could do so much more than as a mere dog, like eat all the tasty meats she wanted AT THE TABLE, driving was quite fun, the whole "internet" thing was so fascinating, the perpetual estrus that humans possessed that initally caught her attention about humanity was still titillating her, and she had even grown to like the garments female humans wore, especially the short skirts, but there was just a couple of things she thought could do improve humans... well, namely the females.
Sally did find while she loved being human, there were things they were inferior at, namely hearing and smelling things. Sally also found after a couple of weeks of being human, she kinda... missed her tail. She knew it was a bit stupid now with her expanded human intellect, but some of her best memories were chasing her tail, plus she realized a dog's tail showed emotion so much clearer than how human females seem to.
Sally's solution came when she was perusing the internet one day after learning about the existence of anime and found images of kemonomimi, namely inumimi, AKA doggirls.
Using the Chronivac, she put in a command for a universal change for all human females to become random kemomomimi, i.e. acquiring animal ears, tails, enhanced senses, strength, and if applicable, things like horns, wings, or udders if their species has them. She also added a command that would make all human females physically fit, cured of and immune to all currently known diseases, and all adults sport breasts no smaller than E-cups. Sally threw in those last features as something she thought would increase females' allure over males, and Sally did want to increase humanity's promiscuity somehow. Also, all the artwork of the kemonomimi anime girls that inspired her to do this all had giant breasts, so she thought it made sense.
Sally meanwhile set an exception in the rules in the Chronivac to make sure she would become a doggirl. She then thought about whether to make this a reality change or not, when... "No, I think it'll be more fun if all the females change around the world and everyone noticed." Sally wondered though, "But how to set this up?"
About then, Richie, who used to be the brother of a former human named Jeff, who was now the family's collie Jessie, and as a result of the Chronivac now made him Sally's brother, came in with his mom Gina, coughing. "I don't know when you got the flu honey, but I'll get you a doctor's appointment for tomorrow." Gina said to the sick Richie.
Sally overheard this from her upstairs room and was hit with inspiration. "That's it!! A virus!! That's how I'll have the Chronivac do it!!" She set up the parameters of a quick-acting virus that would make females change over one to six days, setting her own infection to be one of the faster infections of the lot. With that, Sally hit Enter and awaited the new kemonomimi world.