What does this dream mean? And is this also a coincidence?

Yesterday, I had a dream where I was in a bridge made out of cement and there was a girl holding a puppy on the edge of the bridge and the puppy is just wriggling while the girl holds it. I walk closer to the girl and she turns around. She says "I have to let this puppy go. I can't keep it." she smiles and then drops it and I saw that we were in a really high bridge and the puppy just splatters with a lot of blood coming out. I was shocked and then I woke up. I told my mom about the dream and she says that when she was in a bridge before, she was playing with her puppy in a wooden bridge and her puppy fell off the bridge and my mom saw that there were leeches under the bridge who sucked the blood out of her puppy. I think that it's a coincidence because it was a puppy too, and we were both in a bridge, and the puppy dies.