SOLVED. Childrens book with a young girl who goes to live with her mean grandfather or uncle who has a dog named Thugdon(?). [s]

[Jennifer]

I think this was Scholastic book that I read in the 70's. The girl also had a kitten she hid in her room. The grandfather (or Uncle?) also had hidden some money in a trunk in the water but it was paper money so was ruined. It was kind of a depressing book

[Nóinín]

The House in the Wood aka A Sound of Crying ?
You can read it online over at https://archive.org/details/soundofcr...

[Rainbowheart]

Seconding A Sound of Crying. There's a German Shepherd named Thugdon.

[Jennifer]

That's it!!! Thanks so much