Yes the fist recomendation will be castration. but in some cases you need to use a good treatment and thats the topic here. In some specific cases the owner need to use one more time the female to get his last litter or the dogs are severely stressed by the environmental or because the breeder use imbreeding that could affect just the litter and dont pass for they decendents (f2) in these case you dont need to use castration.but its very rare to happend. Anyway, 2 new medicine are available today and we cant debate here.