I once snuck into a neighbor's apartment to take care of his new puppy. His new, deathly sick puppy that needed 24 hour care to get better, and whose owner decided bar hopping was more important than his new, sick puppy. It cried all day everyday until it was too weak to cry anymore. One night I carried it over to the apartment I was staying in to let it sleep with me for awhile so he would have company.
The puppy got better and we made the neighbor send it to his parent's house where it would get the love and attention it deserved. But the point is, crying dogs make me really nervous now. What if it's sick? What if it's master is hurt and it's trying to alert someone to help?
Turns out it's just a new puppy and most likely just really lonely during the day when it's owners are at work. Also, the owners never told the office they were getting a puppy, most likely trying to avoid paying the pet fees. So yeah, basically I just ratted them out and they're probably going to get in trouble now.
I don't regret telling on them though. I could never forgive myself if it had turned out something was really wrong and I'd ignored it.