A seagull teacher gets kidnapped by gestapo-like peoples

Hello !

I try desesperetly to remember a cartoon movie i watched as a kid. For what i remember :

– There was a seagull teacher (almost every character is an animal). At the beginning of the movie, the student drew a caricature of him on the class board. It becomes alive at one moment to slap the teacher
– The main character is a yellow dog (not sure of that one)
– At one point the teacher gets kidnapped and his class go to save him
– It’s a 80’s or 90’s movie
– The story happens in america
– The graphic style is similar to Oliver and Company

That’s all i remember. No idea if it is a Disney, Dreamworks, whatever-company.

Hope you can help me 🙂