A guinner is a cute baby guinea pig. But guinners could also be full grown guinea pigs, kind of like how a dog can be a pupper.
Most guinners tend to be fat fucks and that's what makes the so god damn adorable. They also are good at attracting ladies.
Female: "Wow what a cute guinner you have there!"
Male: "Thanks, would you like to pet him and maybe go out to dinner sometime?"
Someone who in Facebook comments will scream about how much that cute little puppy or guinea pig is getting abused when in realty they're fine. They will criticize the pets diet, habitat, and interactions based on one video. Facebook vets love to jump to conclusions and cry animal abuse whenever possible.
Wow that facebook vet thinks they know SO much about animals and what is good and bad for them. They should totally judge the owner based on one video.