What’s the name of this animated film?

Hi, can someone please try and help me identify a movie I watched as a kid? It was an animated film featuring animals as characters. Unfortunately I can’t remember an awful lot but this is what I think I do remember:

There is a fox (young boy) called David (maybe wearing a blue coat) whose mother becomes ill and her new partner refuses to get her help from a Doctor (think he was after their fortune or something) and David seeks help from his aunt who he thinks doesn’t like him. There was a scene where the Aunt (also a fox/vixen) flips out after buying clothes for girls when David was born, not expecting him to be a boy. She leaves abruptly after this. I also think David was with a girl (can’t remember what animal) when they went to seek help.

These are the only scenes I can remember so sorry for the obscure memories! I watched this sometime during the early 90s on TV and didn’t catch it all. I’m guessing it was made late 80s, early 90s. I’m in the UK too.

Any help would be greatly appreciated as for some reason it keeps popping into my head and I haven’t seen any sign of it since!

Thanks,

Mat