Spaying a Dog: Benefits, Risks, Timing and Recovery

Benefits of Spaying

• Prevents pyometra, which affects about 1 in 5 unspayed females by age 10^1,14
• Greatly lowers mammary cancer risk when done before the first or second heat^2,8
• Prevents heats, unwanted pregnancy, false pregnancy and ovarian and uterine cancers^8,1

Risks and Trade-Offs

• Urinary leaking, usually while asleep, which can often be managed with medication. Larger breeds such as Vizslas, Dobermans, Weimaraners and Boxers are most at risk.^3,1 See urinary incontinence in dogs.
• Weight gain, because her energy needs drop. Adjust her food and keep her active.^8,4
• Leaking can start years later. In one older study that followed spayed females for 3 to 10 years after surgery, about 1 in 5 became incontinent. Removing only the ovaries carries the same risk as removing the uterus too. Medication makes about 3 in 4 affected dogs dry.¹⁵
• Joint problems and some cancers in certain large breeds, such as Golden Retrievers and Labradors, when spayed before about a year of age.^5,12,6
• Surgical complications such as bruising, swelling or infection, and rarely bleeding.¹

When to Spay a Dog

• Small dogs (under about 45 lb as adults): US guidelines suggest spaying before the first heat, at about 5 to 6 months.⁶
• Large dogs: guidelines suggest waiting until growth stops, anywhere from about 5 to 15 months depending on the dog, to lower joint and some cancer risks, weighed against a higher mammary cancer risk with each heat.^6,5
• Any age: adult and older dogs can be spayed too.¹

Vets usually avoid spaying during a heat, because the uterus has a bigger blood supply then.¹⁶ If she has a false pregnancy, spay after the signs have passed.¹⁷ Spaying in the weeks after a heat can trigger a false pregnancy a few days after surgery in some dogs, so many vets prefer to spay in the resting phase between heats.^18,19

What Happens During a Spay

Under general anesthesia, the vet removes the ovaries and uterus (ovariohysterectomy) or just the ovaries (ovariectomy). Both work equally well in the long run. Some vets offer laparoscopic spays through 2 or 3 small incisions.¹ An "ovary-sparing spay" removes only the uterus, so she'll still come into heat. Few vets offer it.²⁰ A 2023 owner survey found that dogs that kept their hormones longer, including those with ovary-sparing spays, had fewer health and behavior problems, but it included only 159 dogs with this surgery.²¹

Spay Recovery

• Keep her quiet for about 2 weeks, with no running, jumping or rough play, and only short leash walks.^1,8
• Use a cone or recovery suit to stop licking.^1,8
• No baths or swimming until the incision has healed.⁸
• Check the incision daily. Mild bruising is normal.⁹
• Give the pain relief your vet prescribes for the first few days.¹

Will Spaying Change My Dog?

Spaying doesn't change her personality, intelligence or playfulness, and having a litter first doesn't make a dog calmer.⁸ Her metabolism slows, so she may need a little less food.⁸ Her adrenal glands still make small amounts of sex hormones after spaying.²² See also neutering dogs and pyometra.

Frequently Asked Questions

What is the best age to spay a dog?

About 5 to 6 months for small breeds. For large breeds, many vets now wait until growth stops. Ask your vet about your dog's breed.

How much does it cost to spay a dog?

Prices vary widely by region, clinic and the dog's size. Low-cost clinics and shelters are often cheaper.

How long does spay recovery take?

About 10 to 14 days of rest and restricted activity.

Can a dog be spayed while in heat?

It's possible, but most vets prefer to wait because of the higher bleeding risk.

Why is my spayed dog leaking urine?

Spaying raises the risk of urinary leaking. It's usually treatable, so see your vet.