The American Kennel Club (AKC) and the Cat Fanciers' Association (CFA) say the benefits of purebred dogs or cats include that they have been developed over time to show specific traits that are useful for hunting, rescue, assistance and other needs. Animal buyers, including pet owners, may choose a purebred to ensure they know ahead of time the size and other characteristics a young animal will grow into. The CFA also says that purebred cats may make better pets because they have a weaker hunting instinct. The HSUS says that a pedigree is not a guarantee of health and temperament, and that mixed breed dogs and cats often show good characteristics of both breeds, and may be less likely to have genetic defects.