Male vs Female Dog: Which Should You Choose?

Side by side

Size: in most breeds males are larger. The AKC lists male Labrador Retrievers at 65 to 80 pounds against 55 to 70 for females, and male German Shepherds at 65 to 90 against 50 to 70. Intact behavior: males may mark, mount, roam and show inter-male aggression; females have heat cycles and an urge to escape to find a mate, per VCA. After surgery: VCA says these hormonal behaviors are removed or reduced.

Health: spaying prevents pyometra and uterine and ovarian cancer and sharply cuts breast cancer risk; neutering eliminates testicular cancer and reduces prostate disease. VCA says spayed and neutered dogs generally live longer. Personality: VCA states that neither surgery changes personality, intelligence, playfulness or affection. Best for: either sex makes an excellent pet; choose the individual.

Size and strength

The clearest, most reliable difference is size. AKC breed standards usually give males a higher height and weight range: male Rottweilers at 95 to 135 pounds against 80 to 100 for females, and male Doberman Pinschers at 75 to 100 against 60 to 90. In a giant or guardian breed that gap matters for leash control and handling.

In small breeds the difference is often a few pounds, and some breeds list a single range for both sexes. If size is your main concern, look at the parents of a puppy, since they predict adult size better than sex alone. With an adult dog, what you see is what you get.

Intact males: marking, roaming and mounting

VCA lists the hormonal behaviors that neutering removes or reduces: mounting, urine marking, certain types of aggression, roaming, which can lead to car accidents and other injuries, and separation anxiety or fearful elimination. It also says neutering may be used to treat certain forms of aggression, such as aggression between males.

For health, VCA says neutering eliminates the risk of testicular cancer, the second most common cancer in intact dogs, and reduces the risk of enlarged prostate, prostate infection and hormone-related problems such as perianal adenomas and hernias. Guide, hearing and police dogs are routinely neutered without any loss of working ability, VCA notes.

Intact females: heat cycles

An unspayed female goes through heat cycles, and VCA notes that dogs in heat feel an urge to escape to find a mate, a dangerous behavior that spaying eliminates. Spaying also removes the hormone swings that cause false pregnancy after a heat, and VCA lists reduced separation anxiety and fearful elimination among its benefits.

Medically, VCA says spaying prevents pyometra, a fatal uterine infection, eliminates uterine and ovarian cancer and greatly reduces breast cancer: dogs spayed before their first heat have less than a 0.5% chance of developing it. It also notes that letting a dog have a litter first has no calming effect, despite the myth.

During a heat cycle, washable dog diapers help keep discharge off furniture, and for intact males that mark indoors a belly band can protect the house while you work on training.

Timing, trade-offs and personality

VCA is candid that timing involves trade-offs. Spaying or neutering large-breed dogs before bone growth is complete has been linked to a higher risk of cruciate ligament tears and, for females, certain cancers, and surgery before maturity may be associated with noise phobia. Spayed females can develop urinary incontinence later in life. VCA says large breeds may benefit from waiting, so ask your vet about the right age for your dog.

Both surgeries lower metabolism, but VCA stresses that obesity comes from overfeeding and too little exercise, not the operation itself. And on personality, VCA is clear: neither procedure changes personality, intelligence, playfulness, affection or, in males, guarding instinct. Breed, socialization and training shape behavior far more than sex.

How to choose

Start with the individual. Meet the puppy or adult dog, watch how it plays and how it responds to people, and ask the breeder or shelter about its temperament. If you already have a dog, think about the match: ask your trainer or the shelter which kind of companion your resident dog is most likely to accept.

Then plan for the practical side: whether you will spay or neuter and when, a budget for the surgery, and secure fencing while your dog is intact. Book a vet visit soon after your dog comes home to discuss timing, vaccinations and a healthy weight.

This page is general information, not veterinary advice, and it cannot replace an examination by the vet who knows your pet.