We understand that the decision to desex your dog can be complex.

The WSAVA (World Small Animal Veterinarian Association) have recently updated their desexing guidelines. In general, there has been a change in approach from the previous blanket recommendation to desex all dogs before sexual maturity to ensure population control/unwanted pregnancy, to now one of tailoring the desexing recommendation to meet the individual patient circumstances.  

We recommend having a discussion with your vet at the Juvenile Health Check to make a plan around the best time for desexing your pet.

AS A GENERAL RULE WE RECOMMEND:

• Large and giant breed dogs: desexing 18 months + of age
• Medium breed dogs: desexing 12-18 months for age
• Small breed dogs: desexing 6 -12 months+ of age
  (See Breed specific recommendations below)
• Cats: desexing 6 months of age

Note: Ovary sparing techniques can be considered for some females and discussed with your vet. This procedures removes the reproductive tract but leaves 1 ovary behind. The ovary provides the sex hormones that may have some protective effect for joints and cancers in some breeds (see list below). Note the dog will stll cycle (but not bleed), and be receptive to males during heat (2 week period twice a year). The risk of pregnancy, reproductive infections and cancers (except ovarian) is removed as the reproductive tract has been removed.

PUT SIMPLY THE ADVANTAGES OF DESEXING INCLUDE STOPPING:

• Unwanted pregnancy
• Unwanted wandering to find a mate
• Unwanted urine marking in males and in season bleeding in females
• Infections in the uterus (pyometra) in females (affecting approx 4% of undesexed females) and prostate in males, which can be very serious and costly to treat compared to cost of desexing)
• Eliminate the risk of many cancers of the reproductive system- ovarian, uterine, cervical, testicular (though these are not very common). Note mammary cancers can still occur in desexed females and prostatic cancer has higher incidence in desexed male dogs.

There is no clear evidence around the effect of desexing on behaviour. Desexing may reduce some testosterone induced behaviours (particularly in males) such as urine marking, dominant behaviours, territorial aggression. However for dogs displaying signs of anxiety the increase in sex hormones may in fact be helpful and delaying desexing until 1 year of age may be recommended. 

DISADVANTAGES OF DESEXING

• Desexing before skeletal maturity has been associated with an increased risk of joint issues (for example cruciate ligament disease, elbow dysplasia and hip dysplasia) in some breeds, especially larger breeds such as German Shepherds and Labradors.
• Desexed dogs have much higher rates of obesity

• Early desexing may slightly increase the risk of some cancers on some breeds ( Boxer, see breed specific risk below)
• Early desexing may increase the risk urinary incontinence in females (see breed specific risk below)

SPECIAL CONSIDERATIONS FOR FEMALE DOGS UNDERGOING SPAYING

If your female dog is in heat, we recommend postponing her spay surgery for approximately 3-4 weeks until her heat cycle ends. During heat, increased blood flow to the ovaries and uterus makes the tissues more fragile, increasing surgical risks such as bleeding. Scheduling surgery outside of this period minimises complications. 

SUMMARY OF BREED SPECIFIC RISK OF JOINT DISEASE AND CANCERS WITH EARLY DESEXING BY BREED

A study compared the rates of joint disease, cancer, urinary incontinence, uterine infections and mammary tumours in dogs desexed young and those not desexed, across various breeds. Approx 200 dogs from each breed were reviewed. The cancers analysed include lymphosarcoma, haemangiosarcoma, mast cell tumour, mammary tumours.