To avoid unwanted litters and genuinely reduce the hormone-driven roaming and marking tied to females in season (Neilson et al. 1997). Neutering also rules out testicular tumours, especially if a testicle hasn't descended. It won't, however, erase anxiety, reactivity or a lack of training.

When should you spay your female?

It depends mainly on her adult size . In a small female, spaying fairly early is still fine. In a large or giant one, it's often best to wait for skeletal maturity (often 12 to 18 months) to protect her joints (Hart et al. 2020). Spaying her before the first season gives the best protection against mammary tumours.

How much does spaying a female cost?

It depends: it's abdominal surgery, so often dearer than neutering a male, and the price rises with the size of the dog. Only the clinic's quote gives you the real price for your case; ask what it covers (check-up, anaesthetic, cone, follow-up). Cost should never decide in place of the medical picture.

Spaying or neutering your dog

Health & preventionPart of · Health & prevention

Spaying or neutering your dog

Q: Will neutering calm my dog down?

Not like a magic wand. It acts on what's hormonal (sexual roaming, marking, restlessness around a female in season), not on fear, reactivity or training. On those, it's the day-to-day work, with a 'yes' that marks the good behaviours, that makes the difference.

Q: Will my dog get fat after neutering?

Its energy needs drop, so it can put on weight if nothing changes, but that's not inevitable . Cut the portion back a little from the day of the operation and keep an eye on its shape (ribs easy to feel, a defined waist). Planned for, weight gain is very easy to avoid (AAHA 2021).

10 min read

Spaying your bitch or neutering your dog isn't a question of right or wrong: it's a decision to take with your vet, based on her size, her sex, her age and her lifestyle. No single rule fits every dog, and there's nothing to feel bad about, whichever way you go.

There's no wrong choice, only the right one for your dog

Two camps often square up: “always neuter early” against “never do it”. Both are wrong. Neutering has real benefits, but also real trade-offs, and the balance between the two shifts from one dog to the next. A small bitch and a giant-breed male are not in the same situation. So the right answer depends on your dog, it gets weighed up with your vet, never by copying the neighbour.

The real benefits

In females, spaying removes the risk of pyometra, the womb infection that affects, according to a large Swedish study from 2001, close to one entire bitch in four before the age of ten.
Many people believe that spaying a bitch before her first season lowers the risk of mammary tumours, the most common disease in the entire bitch. But the scientific review that examined this link, in 2012, judged the evidence too weak to state it with any certainty, both the protective effect itself and its link with age. Science hasn't settled the question.
No more seasons twice a year, so no more accidental matings and no more repeated phantom pregnancies.
In males, a 1997 veterinary study shows that neutering genuinely reduces roaming after females and the restlessness that comes when a bitch nearby is in season, and that it rules out testicular tumours.

The real trade-offs

In large and giant breeds, neutering before growth is complete can raise certain joint risks, such as a cruciate ligament rupture (a ligament in the knee) or dysplasia (a hip or an elbow that forms badly), and certain cancers. It depends heavily on the breed, and stays very low in small dogs, according to a large American study from 2020 that followed 35 breeds.
Some spayed bitches develop, sometimes years later, urinary incontinence (leaks while resting), which is more common in large breeds. It usually responds well to treatment.
After the operation, your dog burns less energy: if you don't adjust the bowl, he puts on weight.

Weight gain after neutering isn't automatic: cut the ration back a little from the day of the operation and keep an eye on his shape (ribs easy to feel, a visible waist) over the following months. Anticipated properly, it's very much avoidable, according to the 2021 guidelines from the American Animal Hospital Association (AAHA).

The right moment depends above all on size

Your small dog

Neutering early puts almost no risk on his joints.
In small dogs, growth finishes early: no need to wait as you would with a big dog.
Settle the timing with your vet, there's no rush.

Your large or very large dog

Sex hormones help “close” the growth of the bones.
It's usually better to wait until bone growth is finished, often around 12 to 18 months, sometimes later.
That same 2020 study shows the right age really does depend on the breed.

Your bitch

As she ages, a bitch left entire is mainly at risk of pyometra and mammary tumours.
Many people believe that spaying her before her first season protects better against mammary tumours, but science has no solid evidence for that.
If she stays entire, learn to spot the signs of pyometra.

Your male

Neutering acts on the hormones (roaming after females, marking), not on training.
An undescended testicle (cryptorchidism) is a genuine reason to neuter: the tumour risk there is very real.
A reversible hormone implant can sometimes let you “test” the effect before deciding: talk it through with your vet.

The decision, with your vet

Cases where it's often a real plus

Your bitch is diabetic: spaying helps stabilise the disease.
Your male has an undescended testicle (cryptorchidism).
Your male switches off and bolts as soon as a female is in season, and management alone is no longer enough.
Your middle-aged bitch is still entire and you want to rule out the risk of pyometra.

Cases where it's better to talk it over with your vet

Your dog is large or very large, and still growing.
You're hoping to fix a behaviour problem (anxiety, reactivity): neutering doesn't wipe it away.
You're unsure about the timing: nothing is urgent, choose it with your vet.

After the operation: a few quiet days

A routine spay or neuter mostly calls for rest. In the bitch, it's abdominal surgery, a little “heavier” to recover from than the male's neuter, which is more superficial.

10 to 14 days

Rest for roughly 10 to 14 days

Your dog mustn't run, jump, take the stairs freely or have a bath while the skin closes up, according to the guidance from the American Society for the Prevention of Cruelty to Animals (ASPCA).

Keep the cone on until the wound has healed

Saliva and licking soften the wound and infect it. Don't touch the incision, don't clean it: protect it, and keep an eye on it.

Outings on a short lead, even in the garden

Take him out just to relieve himself, no freedom and no rough play.

Swap physical exercise for mental exercise

Offer him suitable chewing, a snuffle mat, calm scent games: a dog with something to do keeps to his rest without frustration.

Don't miss the check-up appointment

That's what gives the green light, not appearances: a dog “looks recovered” long before the tissues are strong.

If you choose to leave your bitch entire: within the two months following a season, a bitch who is flat, drinking and urinating a lot, vomiting or with a distended belly, with or without any discharge, may have pyometra. It's a life-threatening emergency: get seen without delay. A Swedish study from 2016 shows that the form without discharge is the most serious.

Hart B.L., Hart L.A., Thigpen A.P., Willits N.H. — Assisting Decision-Making on Age of Neutering for 35 Breeds of Dogs, Frontiers in Veterinary Science (2020)
Beauvais W., Cardwell J.M., Brodbelt D.C. — The effect of neutering on the risk of mammary tumours in dogs: a systematic review, Journal of Small Animal Practice (2012)
Jitpean S., Hagman R. et coll. — Closed cervix is associated with more severe illness in dogs with pyometra, BMC Veterinary Research (2016)
Brodbelt D. et coll. (CEPSAF) — The Confidential Enquiry into Perioperative Small Animal Fatalities, Veterinary Anaesthesia and Analgesia (2008)
Neilson J.C., Eckstein R.A., Hart B.L. — Effects of castration on problem behaviors in male dogs (1997)
Nutrition and Weight Management Guidelines, AAHA (2021)
Egenvall A., Hagman R., Bonnett B.N., Hedhammar A., Olson P., Lagerstedt A.S. — Breed risk of pyometra in insured dogs in Sweden, Journal of Veterinary Internal Medicine (2001)
McGreevy P.D., Wilson B., Starling M.J., Serpell J.A. — Behavioural risks in male dogs with minimal lifetime exposure to gonadal hormones may complicate population-control benefits of desexing, PLOS ONE (2018)
Starling M., Fawcett A., Wilson B., Serpell J., McGreevy P. — Behavioural risks in female dogs with minimal lifetime exposure to gonadal hormones, PLOS ONE (2019)

Going further

guideThe real cost of a dogThe price of the operation is only one line in a dog's overall budget: here's how to find your bearings before you decide.Read the guide guideTreating a minor wound on your dogAfter the operation, the scar needs a bit of watching: this guide helps you tell a wound that's healing well from one that's getting infected, and know when to call the vet.Read the guide guideA dog in season: understanding the cycleUnderstanding your bitch's cycle helps you choose the right moment to spay her.Read the guide guideFeeding your adult dog wellA neutered dog often needs fewer calories: this guide helps you adjust his meals to avoid weight gain.Read the guide guideDog vaccines and boosters: the key milestonesThe neutering consultation is often a good moment to take stock of booster vaccinations.Read the guide guideSpotting a life-threatening emergency in your dogAfter the operation, certain signs mean calling the vet urgently: learn to recognise them.Read the guide

Frequently asked questions

Why neuter a male dog?

To avoid unwanted litters and to genuinely reduce roaming after females and the marking that comes with bitches in season, according to a 1997 veterinary study. Neutering also rules out testicular tumours, especially if a testicle hasn't descended. What it doesn't do is wipe away anxiety, reactivity or a gap in training.

Do you really have to neuter your dog?

There's no single answer: it's a decision to weigh up with your vet, based on breed, adult size, age and lifestyle. With a big dog, it's often better to hold on until growth is finished. And managing the environment against escapes stays useful, neutered or not.

When should you spay your bitch?

It depends above all on her adult size. In a small bitch, doing it fairly early remains acceptable. In a large or giant one, the end of bone growth (around 12 to 18 months) is still the marker to aim for in order to protect her joints, according to a 2020 American study covering 35 breeds. Many people also believe that spaying her before her first season protects better against mammary tumours, but the scientific evidence for that effect remains weak.

How much does it cost to spay a bitch?

It depends: it's abdominal surgery, so it often costs more than neutering a male, and the price goes up with the size of the dog. Only the clinic's written quote gives you the real price for your case; ask what it covers (pre-op check, anaesthesia, cone, follow-up). Cost should never take the place of the medical decision.

Will neutering calm my dog down?

Not like a magic wand. It acts on what is hormonal (roaming after females, marking, restlessness around a bitch in season), not on fear or training. Owner questionnaire studies actually find more fear and reactivity in dogs neutered young. On those points, it's the day-to-day work, with a “yes” that marks the good behaviours, that changes things.

Will my dog put on weight after neutering?

His energy needs drop, so he can put on weight if nothing changes, but it's not automatic. Cut his ration back a little from the day of the operation and keep an eye on his shape (ribs easy to feel, a visible waist). Anticipated properly, weight gain is very much avoidable (AAHA, 2021).

Updated on July 11, 2026Sources

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