Do you know what book this is?

When I was 6 or 7 I read this book. I don’t really know why I want to find this book but I just feel like I need to.
I think it was supposed to be a book for older children, as I do vaguely remember some minor swearing. It was about a boy who I think was a teenager who had a dog (a deerhound or a wolfhound) and he made a cart for the dog to give kids rides in. I have no idea what it was called or who wrote it but any help would be appreciated SO much!
This probably isn’t enough information, but I guess I can just hope one of you may have read it. I guess all I can do is continue searching through Google for it.
Thank you!