Best Answer: Age of your dog should be one year for spaying. Six months is the age where most people feel more comfortable spaying their pet, but vets can do it as early as 2 1/2 to 3 months. My own dog was neutered at the shelter at 3 months old. Prices vary depending on the vet. Anywhere from $20-$80. There are spay and neuter clinics which even do it for free or near free.