Let's begin with the poor bloodhound. Most of the time when we see him, he's talking about what may be, or is, wrong with him, among other gloomy things. However, towards the end of the Pet Shop episode, he smiles as he talks about himself getting adopted by a nice family. At least he counts his blessings!
In the US series, the Buffalo talks about how he's gone through hard times, but his grandchildren make life worth living. The animation has a few tears roll down his face and he's clearly choked up in happiness.