You may be served personally, or by another person of suitable age, mail or substituted service as determined by law and / or the judge. (rocketlawyer.com)
The most suitable age would be 6 - 12 months for a front carry, or 12 - 24 months for a back carry. (daddilife.com)
If you do not intend to allow your dog to breed, a vet can advise you on the most suitable age for sterilization. (breedingbusiness.com)