I volunteer at an animal shelter, run by a major animal care organisation. Every time I go in, there's some horror story or other.
The least horrible is the terribly matted animals. So thick with mats that the skin of their belly is being pulled to their chin all the time, and vice versa. And the skin under the mats is so degraded and in such poor condition that sometims we don't want to try bathing the animals until the vet has seen them, even though we know they need to be clean. You try to tell yourself the animal is a stray - sometimes I don't ask if it's a stray or a surrender because I know how angry I'm going to get if its a surrender.
(Side note to anyone who owns a Maltese Terrier or Maltese cross: your vet is not kidding about brushing the dog every day! Something about that fur just makes mats happen out of nowhere.)
Then there's the people who bring in dogs who've bitten someone. If we know the animal has bitten someone, even with provocation, they're highly unlikely to pass the temperament test and if they don't, they're going to be put to sleep. We tell the owner, and try to discuss the situation.
If the animal is likely to be fine if it's properly trained, we practically beg them to talk to a behaviour specialist, obedience trainer who understands fear aggression, vet, or the like. Once every other blue moon, the person takes our advice.
If they don't take our advice, or the animal isn't going to be fine with training, we still ask if they would take the dog to the dog's familiar veterinarian to be put to sleep in familiar surroundings, with their family nearby.
If we take them, they stay in a small concrete and steel cage(*) for eight days, marked with 'WATCH' because they're a biter so we volunteers can't go in and keep them company, or take them on walks. (Paid, insured staff handle the WATCH-marked animals.) Then they go on a long car trip to get temperament tested, and then put to sleep. We don't want to traumatise the poor critter like that. They don't deserve it.
(*) We're getting new quarters later in the year. New buildings for us, and much better housing for the animals. Yaaay!
It's really sad when people bring us pets they no longer want. Treating animals as disposable. I'm not meaning people who've had sudden, unexpected life changes: my own girl-kitty came from a woman who had a stroke and suddenly had to go into a nursing home. I'm meaning the people who see animals as disposal and us as a dumping ground.
It's worse when people refuse to admit to themselves that they're bringing the animal in for us to euthanise, and put their animal through a scary, traumatic experience when it could be a gentle one.
No dog wants to be in a shelter. Walking down the cage rows is heartbreaking and heartwarming at once. Every dog but the trauma-frightened ones is up against the front of the cage, trying to get you to take them for a walk, give them loving. Hoping it's them you're coming for. And the trauma-frightened ones are looking to the door, half-hoping and half-fearing you're coming to talk to them. If you sit in front of their cage and let them come to you, they will. And they'll bravely lick your hand, and look up at your face as if saying 'is that okay?'
Dogs just want to be Good Dogs. And sucky humans let them down. It breaks my heart.