I have a giant breed senior dog that is unable to walk very far in his old age. He was so happy to hop in here when he got tired today. It's roomy, and easy to load a big ol dog into. I have a 125lb Mastiff, and was close to 140lb in his younger days. This could easily accommodate even bigger guys/ gals than Big Doug. Think Wolfhound, or Great Dane. This wagon is easy to pull and is super smooth. I found it hard to find something sturdy enough for a dog like mine. If you're looking for a sturdy wagon for anything, this is the one.