There are many differing opinions about the benifits of spaying and neutering your pets. Some research on the age at which to spay and neuter dogs was published by Margaret Root-Kustritz, DVM, PhD of the Univ. of Minnesota and can be seen at PetMD.

The following is a list of reasons to Spay or Neuter your Pet from the ASPCA website:
These are general observations and are supported by several scientific studies, however your experience may not always reflect these observations.

  1. Your female pet will live a longer, healthier life.
  2. Neutering provides major health benefits for your male.
  3. Your spayed female won’t go into heat.
  4. Your male dog won’t want to roam away from home.
  5. Your neutered male will be much better behaved.
  6. Spaying or neutering will NOT make your pet fat.
  7. It is highly cost-effective.
  8. Spaying and neutering your pet is good for the community.
  9. Your pet doesn’t need to have a litter for your children to learn about the miracle of birth.
  10. Spaying and neutering helps fight pet overpopulation.