no point in keeping a dog that doesnt do everything you ask of it, you will never be happy with it and it will never end well.
but sometimes you dont have the choice, if you rear a dog from a pup, and it isent a good at ferreting as you wanted it to be, but was top notch on the lamp, what would you do, just get rid of the dog and say f**k it, i will get a new one, or stick with it and work more on the discipline it isent so good at, with the chance it may improve? as i said what you put in is what you get out!!!
some dogs just dont make the grade full stop mate, thinking any differenet