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What you should know about sterilisation: Development and your dog’s sex hormones

A condition of sale of your puppy is that you will sterilise (otherwise known as desex, spay, or neuter) your puppy.

Sterilisation should occur between 12-24 months old.

Desexing too young can have detrimental effect on your dog’s life including the following diseases:

  • Hip and elbow dysplasia
  • Cruciate ligament injury and tear
  • Arthritis and joint disease
  • Lymphosarcoma
  • Hemangiosarcoma
  • Mast cell tumour
  • Shorter life expectancy

Research now shows that desexing before 12 months old (in larger breed dogs) signficantly increases the risk of joint disorders, in particular cruciate ligament tears and dysplasia. Some research suggests this risk increases by as much as three times if the dog is spayed at a young age.

For the dog’s sake it is very important that they be allowed to reach sexual maturity (in females, this means having one to two heat cycles) before being desexed. Until a dog reaches sexual maturity, their bones and joints are still developing and ossifying (forming and hardening). Joint plates do not close until sexual maturity. Visit our Exercise, Growth and Joints page.

Removing the ovaries or testes disrupts the production of hormones that play an important role in body processes such as bone development and when to signal growth plate closure.

Veterinarians are now applying the research (which shows that early sterilisation increases the risk of dysplasia, impacts bone and joint development, and increases joint disease) in their practice and recommend to delay sterilisation in larger breeds such as labradors, golden retrievers, and german shepherds until they reach sexual maturity, to decrease their risk of dysplasia and joint disease.

Most breeders who understand the risks to growth and development have been making this recommendation for many years, and finally the scientific studies to evidence this are being published.

Female Labrador’s Heat Cycle

As a female labrador is sexually maturing, she will come into ‘heat’ around 8-12 months of age and about every 6 months after this.

Part of the female dog’s natural reproductive cycle is being ‘on heat’ or ‘in season’, during which time she becomes fertile. A heat cycle lasts about 3 weeks and happens about every 6 months. During her heat, she will bleed on and off for this period of time.

It is important that females be allowed to have one or two seasons before sterilisation, to ensure they have reached sexual maturity, since disruption of sex hormones affects growth and development (especially of bones and joints).

It is critical that she does not come into contact with any male dogs, as she is fertile during her heat. Females on heat should not be exercised in public and cannot enter dog training grounds. Ensure she is kept in your own fully secure yard, preventing her getting out and any males getting in. Males can detect a female on heat from a long distance and will climb, jump, dig, or whatever it takes to get to her. Male dogs will track and follow a female on heat for a long distance, several kilometres, so make sure she is safely secure.

Managing a female dog on heat is otherwise not that difficult. She will usually become more cuddly and clingy to her humans. It is important to give her the extra affection she is seeking. Lots of hugs and reassurance.

As for bleeding, they usually do not bleed too much and are pretty good at cleaning up after themselves by licking. Although being outdoors in the yard is going to be more convenient, cuddles and affection must not be neglected. When she comes inside the house, you can use doggie diapers to contain the bleeding. We use Women’s Tena Pants Size Medium (from Chemist Warehouse) as they are the best fit we found. Just cut out a hole with some scissors for the tail! Only use a pad for a short time (1-2 hours) otherwise she can get an infection (yes, they can get toxic shock syndrome). Make sure you are aware of a condition called ‘Pyometra’ (pus in the uterus) when you own a female dog who is not yet desexed – please research pyometra and monitor for any signs of this condition.

As for bedding, we dont worry if it gets a few spots, we just wash it with disinfectant.

As your labrador will be desexed between 12-24 months old, she will probably only have 1-2 cycles before she is spayed and then you will not have to worry about this in the future. Remember, what it is a temporary inconvenience to us humans, has life-long benefits for her in terms of her health.

Castrating Male Dogs

Traditionally, male dogs are neutered by a small and simple surgical procedure during which the testicles are removed. Recovery time is quite rapid and the dog becomes infertile within a couple of months as no more sperm are produced.

Remember that they can still have stored sperm up until 1-2 months after being castrated.  So, do not allow contact with any fertile females immediately after spaying, as he is not infertile until 1-2 months later.

In male dogs, the health risks of neutering too young almost certainly outweigh any health benefits.

Similar to the opposite gender, is important that males be allowed to reach sexual maturity – said to be around 12 months old. ALTHOUGH males can become fertile as young as 6-8 months old. At this age, they are nowhere near finished growing and maturing yet.

Removing the testes removes the dog’s main source of testosterone (sex hormone) which is responsible for a number of behavioural and physical characteristics. It has recently been determined that testosterone is involved in more aspects of your dog’s health than previously thought, including growth and protection from injury and disease. Removal of sex hormones at a young age affects the growth and development (especially of bones and joints).

A male dog neutered before he reaches sexual maturity will look less masculine and have a more feminine head. Muscle tone and bone density can also be affected.

Male labradors are not known for as many undesirable behaviours compared to other breeds. Boisterous adolescence is normal. Labradors tend to become calmer as they mature. Behaviours that might change or be reduced after castration include leg cocking and roaming. Roaming is a behaviour easily prevented by secure fencing and increased mental stimulation and exercise.

Labradors are not naturally known for aggressive traits. In the unlikely event that your male labrador is showing dominant or aggressive behaviour, please chat to us. Studies have shown that aggression is unlikely to lessen by castration. Help from a dog behaviourist is more likely to benefit.