you're often taking on someone else's problem

I agree, we tried to adopt a dog last year, he was cute, playful and healthy. The woman assured us he was a great dog, and he seemed really nice, so we paid the fee, filled out the app and took him home. Once he came in contact with our 3 year old, things changed, he kinda looked at our kid as "prey", circled her about three times with a really shifty look then decided to have a taste, I intercepted him mid pounce (luckily the dog was unharmed as well as my child) but he immediately went back, I understand trying to work with character flaws but obviously we couldn't have that in the household.