The most obvious benefit of sterilising our pets is to keep us away from problem of having more pets that we can accommodate at home. We all know that no one can tell how many baby a pregnant dog or cat will deliver baby at the end of their pregnancy. We saw extreme cases where a mother dog or cat deliver more than 10 babies. We also know that an adult female dog or cat can have two pregnancy periods every single years. If you have a female pet and let her mate and get pregnant, you can imagine how quick the growth of population can be, only in your home. Note also as the babies will carry their own babies later on.