iv got same problem with my 10 month old bullx il be waiting to here the replies too mate. iv heard mixed things most say wont make a difference if its in them they will do it  not long got back from vets in our area its it caerwys a well known vets he has told me not to castrate him yet as there is no worries only when he becomes around the age of 9_10 yrs it may to to cancer but not at the age of 15 months so we will see what happens