My uncle worked Manchesters on Rats for years, Im talking about 20yrs ago now. I can remember them being very efficient, however they were a nightmare around other dogs always fighting, in the end he had no more due to this. The only one I know now is a pet, still very sharp with other dogs but is also very nervy around people, its NOT its upbringing as they have had Fox and Jack Russell terriers all their life.
Dawn.