In the year 2040 women attempted a rebellion to take control of the world, men managed to win the war and made all women become second class citizens and lost the title women and were all referred to as girls. From the chaos the Male Republic became the only government on Earth, All girls over the age of 18 were forced to be fully naked unless their masters pay massive fees for them to wear clothes.
Once a girl is 18 unless a parent or master pays for a no sex collar (typically to keep them virgins to increase sale value) which also makes them need to be accompanied in public at all times unless in a bathroom or a no girls establishment where they are left outside on a safety pole. This is an expensive path to go down for a non enslaved girl which helps motivate people to sell them sooner then later. Ones who keep them for too long often go into debt and have to sell the girls. Once a girl is enslaved the master controls all sex she has but most don't enslave the girls but most parents will not enslave their daughters.
All other girls have to have sex with anyone who tells them to and will become the property of them if they refuse but unless they are owned by someone else can be enslaved by anyone including themselves. Many still do get married but are legally seen as kept slaves and kept naked. Girls are not allowed to own money or property to make any independent girls convert to slavery so most either find a husband or master so they are not homeless. The farther north and south you go the more common enslavement is due to the weather.
Any girl can be transformed into a slave or a pet slave with pet slaves being more popular. Typical pets ranged from dogs, cats, cows (better known as hucows), horses (better known as ponygirls although some prefer whorses), rabbits and pigs. There are others animals like monkeys, mermaids, and birds but these are not as common and typically owned by the rich. Girls are transformed and mentally trained so they will be like this for life and the only thing that can be changed is the animal they are but that is expensive and is rare.
Most pets have simple gear attached to them like butt plug tails, muzzles, and paw/ hooves gloves/ boots (typically only for pets in training the only that wear boots permanently are some ponygirls). Genetic alteration to make the girls look like the animals is possible but is expensive and rare. The only common type is a tail since many don't like the looks of butt plugs or want them to always have a tail. The most common gear is a collar or harness and bells on the nipples. Most girls are given daily drugs to keep hormones up keep their bare feet from infection and for hucows to increase breast milk production.