I know a person that did this. They had this dog for a ton of years and posted about it on Facebook about how it was so sad he had to get put down but it was the right thing to do. I was curious what was wrong with him. My father told me it was because he had gotten really aggressive. This was super weird to me because I'd known him so long. Turns out that aggressive actually meant that he'd killed a chicken that they let roam their yard and then attacked some another time after that so they took him to the vet and had him put to sleep. My dad couldn't understand why that made me so pissed off and then they were trying to get sympathy online for it almost like something happened to him and not like they literally killed him instead of keeping him on a leash or the chickens put up because apparently they're lazy AF

Sorry for the rant this is just somewhat recent and I'm still so pissed about how awful people are.