Bio-pets came out in the early 3000's, originally weapons developed by America, China, and Japan against Russia and their allies in World War 3. They were humanoid, with animal like legs and paws, tails and ears, smallish muzzles, and stood upright. Most had the intelligence of a ten year old, and their durability allowed them to move independent of the army during the Russian winter, setting up forts and raiding enemy camps.
Once Russia was subdued, no one really knew what to do with the child-like animals. Many wanted to decommission them, AKA put them down. That is, until the Queen of England (The Queen is eternal even in the year 3000) took a Bio Corgi named Lester as her personal companion and body guard. People rallied to have the war veterans released, and they were. Soon, Bio-Pets were as popular as cats and dogs.
It turned out they could communicate with animals quite easily, and they could learn and think the same as a ten year old. They were awarded the same legal rights as children, owners being replaced with legal guardians. Many worked easy jobs, such as store-clerks or animal trainers; a few were zookeepers.
Bio-pets were a normal, integrated part of society. They were everywhere. It was all the worse when the plague hit.
It started in Canada. The first victim was a cat-girl named Macy. She got a bad cough and a stuffy nose, normal flue symptoms. But it only escalated from there. Her fur started falling out, her muscles and mind deteriorated until she was little more than a snarling, hungry skeleton. Finally, the vets put her down. More cases started popping up everywhere, spreading to animals and Bio-Pets alike.
Two years later the plague went dormant again, and any remaining Bio-Pets were put down as a precaution. Most animals were dead, and those that survived were in special protection programs. Only the obscenely wealthy could afford them.
People were desperate for companionship, and the Governments were desperate to prevent a total economical collapse. That's when the first human pets came out.
They were mostly non-violent criminals and volunteers, though why anyone would volunteer for experimental body modification is beyond me. It took a few years and quite a lot of failure, but in the year 3400 the first batch of Human Pets was on the market.
