Recommended timing by pet
| Pet | Commonly recommended age |
|---|---|
| Cat (male or female) | By 5 months ("fix by five"); from 8 weeks in shelters |
| Small dog (< 45 lb) | Around 6 months |
| Large dog (45–90 lb) | Often 9–15 months (let growth finish) |
| Giant breed (> 90 lb) | Often 12–18 months |
| Female dogs | Timing around the first heat is breed-specific — ask your vet |
Recent research shows the "best" age varies by breed and sex, especially for large dogs. This is an area where personalised vet advice really matters.
Benefits of spaying & neutering
- No unwanted litters — and fewer homeless pets overall.
- Females: removes the risk of pyometra (a life-threatening uterine infection) and greatly lowers mammary cancer risk, especially when done early.
- Males: eliminates testicular cancer and reduces prostate problems.
- Behaviour: often less roaming, marking, and some hormone-driven aggression.
Things to weigh
- Large-breed timing: spaying/neutering very early may slightly raise the risk of certain joint issues or cancers in some big breeds — hence the "let them grow" advice.
- Weight: metabolism slows after the procedure, so adjust food to prevent weight gain — see our food calculator.
- Recovery: usually 10–14 days of rest and an e-collar to protect the incision.
⚠️ Guidelines are evolving and breed-specific. This is general education — your veterinarian should set the right timing for your individual pet.
Frequently asked questions
How much does spay/neuter cost?
Roughly $50–$500 depending on species, size, sex, and clinic — low-cost and shelter clinics are at the lower end. See our vet cost estimator.
Will it calm my pet down?
It can reduce hormone-driven behaviours like roaming and marking, but it won't change core personality or fix anxiety/training issues — those need behaviour work.
Is it safe?
Spay/neuter is one of the most common, routine surgeries vets perform, with very low risk. Your vet will do a pre-op check and advise on recovery.
Related: vet cost estimator · new puppy checklist · new kitten checklist.