My daughters started the local animal rescue and we've seen a lot of abused animals. One family bought a 6 week old puppy on craigslist and their son dumped battery acid on it and it died. They went back to the seller and demanded another one for free and the seller gave them another puppy from the same litter. About a week later the father took the puppy to the local emergency vet because his son had chopped off the puppy's tail and ears and couldn't get the bleeding to stop. The vet called the police and they seized the puppy and asked the rescue to hold it as evidence in a cruelty case. The family demanded the puppy be returned and sued the rescue to get it back. A local lawyer represented the rescue for free. The family went on a social media rampage and trashed the police and the rescue.
Another guy wanted to adopt a dog and filled out the paperwork. When he found out that the rescue had contacted his former vet for a reference he went nuts started calling my house and threatening my daughter.
On at least two separate cases, renters were thrown out of their homes for non payment of rent and left their animals in the house to die. The two dogs ate sheetrock to survive and were near death when we got them.
We see lots of dogs that were used for bait dogs. People tie them up and put muzzles on them and then let their fighting dogs tear them apart to get used to killing other dogs.