Spaying and neutering dogs: RTE Today Show Petfix Pet Clinic


In this week’s Petfix pet spot, Pete gives an update in the latest scientific advice on whether, and when, to spay and neuter female and male dogs.

First: To breed or not to breed?

The main message is that there is zero benefit to male and female dogs and cats from breeding: in fact, the process of pregnancy carries some risks. And up until COVID, there has always been a problem with overpopulation of pets in Ireland, with many dogs needing to be euthanased in dog pounds because there were too many. This has changed with the surge in interest in dog ownership during the pandemic, but it is likely to swing back again soon enough as people go back to work. So everyone has a social responsibility to ensure that their pets don’t contribute to a surge in unwanted dogs

Say NO to unplanned litters of pups and kittens

As far as planned litters, just be aware that there is a lot more work involved in breeding than you might expect:

  • pre-breeding health tests such as hip xrays, eye checks, heart checks
  • risks to mother during pregnancy and birthing process
  • two months of sheer hard work when pups and kittens are born
  • So if you do plan to breed, make sure you do your research first (some helpful articles on this on

Second, to spay or not to spay?

The operation in females is called spaying, or technically, ovarohysterectomy (uterus and ovaries are surgically removed). Operation costs €200 to 350, depending on size/age of dog.

Reasons to spay:

  • Preventing unwanted pups
  • Preventing seasons – entire females come into season twice a year, with bleeding and attractiveness to males lasting for three weeks each time. This can cause management issues with pets in the home.
  • Preventing cancer. Hormones have a strong effect on cancer. Repeated exposure of mammary tissue to high levels of oestrogen predisposes females to mammary cancer, the most common cancer that we see in dogs: if a bitch is spayed before her first season, the risk of cancer is reduced by 99.5%. In cats, spaying at any age reduces the risk of mammary tumors by 40% to 60%. In Norway, where spaying dogs is illegal (it’s regarded as a “mutilation”), over 50% of female dogs suffer from malignant mammary cancer.
  • Preventing womb infections. An infected womb, known as “pyometra” is a serious illness, with a mortality rate of 4 – 17% even when comprehensive treatment is given. 25% of unspayed females developed this problem by 10 years of age. Spaying involves removing the womb, so obviously pyometra is completely prevented.

Reasons not to spay:

  • Female dogs are 50% more likely to become overweight or obese, so it’s important to control their diet carefully if they do have the operation
  • A small number of dogs develop urinary incontinence after spaying, but this can be effectively treated with drops in their dinner if it does happen. In contrast, mammary cancer can be malignant and untreatable in some cases.
  • Early spay/neutering of large and giant breeds of dog ahs been linked to an increased incidence of osteosarcoma (bone cancer), so it is now recommended to leave these breeds until sexual maturity before doing the operations (e.g. 18 months of age).

When to spay?

Nowadays, vets say that a decision on spay/neuter should be done on an individual basis, depending on the specifics of the pet, to optimise timing. For small and medium breeds, usually 5-8 months is right. For large and giant breeds, it may be best to wait till they are older, but talk to your vet is the message.

Third, to castrate or not to castrate?

The operation to neuter male dogs is called castration, unpleasant as that word may sound to many people, especially to many men.

Reasons to castrate

  • Testicular cancer is the second most common cancer in male dogs, and neutering (castration) eliminates that risk because the testicles are surgically removed.
  • The prostate gland is also prone to disease in older dogs (just as it is in older male humans). Benign prostatic hyperplasia, affects 60-100% of dogs over 7 years of age, often causing difficulty urinating or defecating. This is completely prevented by neutering.
  • Hormones have a significant effect on male behaviour too. In one study, neutering reduced roaming behaviour of dogs by 90%, aggression between males by 62%, urine marking behaviour by 50%, and mounting behaviour by 80%. If your pet shows these problem behaviours, neutering will help to solve them.

Reasons not to castrate

  • The male hormone, testosterone, helps dogs to feel confident. If this is removed by neutering, some anxious, fearful male dogs may be less likely to develop the confidence they need to function well in social environments.
  • Neutered male dogs are 50% more likely to become overweight or obese, so it’s important to control their diet carefully if they do have the operation

When to castrate?

While smaller dogs should be neutered at around six months of age, it’s now recommended to allow large or giant breeds of dogs to develop to full maturity, at around 18 months of age, before doing the operation. This helps to avoid some joint and bone problems that are more common in these breeds if the operations are done whey they are younger. And there are some specific breed related issues e.g. Dachshunds are more likely to develop disc disease in their spines if they are neutered when younger.

Again, the answer for pet owners is simple: speak to your vet to find out what’s best for your pet, or visit Petfix Club to learn more.

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