As I remember, 'Toto' is a dark grey/black-coloured dog of uncertain breed. Could you not get a hairy fur-effect fabric and make up a costume? Don't know exactly where you could get such a material, but someone yet may come up with an idea as to where.
There used to be a company in London called Theatre Zoo that hired animal costumes. They provided them for plays and films, don't know if they are still there.