The British veterinary association recommend all dogs are neutered to prevent unwanted litters.  There are lots of myths and hearsay around neutering and not a lot of scientific evidence around how to guide owners to make the right decisions and timings.  We endeavour to keep as current as possible on the subject.  Our guidance below is based on what evidence is currently available

• Male dogs may be neutered from 6 months of age providing both testicles have descended
• Female dogs may be neutered from 6 months provided it is before a season, if a season has occurred then they must wait 3 months after the first day bleeding is seen
• There is no current evidence that neutering from 6 months onwards has any detrimental effects on growth, however until further evidence is found we recommend large breed dogs (those over 25kg of adult weight) be at least 12 months of age before neutering.  This is a controversial subject and our senior vet is constantly reviewing current literature to make sure we give the most up to date and correct advice.  Diet however is important at this age.
• There is much debate about letting a dog have a season before spaying to help reduce the purported behavioural issues surrounding pre-puberty neutering.  We are monitoring the literature and will make recommendations as they arise.  We currently feel there is little evidence to support these claims but will change our advice and policy if it comes to light.
• Spaying a dog in season is not without  risk as the womb is very vascular and may lead to excess blood loss or  false pregnancies
• Certain breeds are more prone to urine dribbling post spey and owners of these breeds usually would be advised to have a first season before spaying as they are prone to urine dribbling when hormone levels (oestrogen drops) they are Doberman, Rottweiler, Bearded Collie, Weimerana, Irish setter, Boxer, Giant Schnauzer and Old English sheepdog.
• Benefits of castration – prevents straying, testicle tumours, prostate inflammation (prostatitis) and may reduce aggression and boisterousness.  Behaviour issues should be  discussed further with the VN or VS as some nervous animals will benefit from behaviour modification program before neutering as taking testosterone away (bravado) can make some dogs more fearful
• Benefits of spaying – prevents unwanted pregnancies, straying, womb infections (Pyometra is common), mammary tumours, false pregnancies and can reduce aggression and boisterousness in some dogs. Mammary mass risk is reduced to 0.05% preseason, 8% post season, 26% under 2 years then the risk increases year on year.
• Cons of castration –can alter coat making it slightly more fluffy, animals need less calories and will gain weight if rations are not adjusted for this, can make an already nervous dog worse (discuss with VS)
• Cons of spay – can alter coat making it more fluffy, animals need less calories and will gain weight if rations are not adjusted for this.  All bitches are at risk of incontinence (2% of the population) whether spayed or not. However, the risk can increase by 16% after neutering due to hormone levels decreasing (oestrogen) post spay.  This can easily be treated and the risk is low.  Waiting for a season in the general population of dogs does not appear to reduce this risk (but note previous for at risk breeds)
• There has recently been some published dated citing behavioural changes if bitches are spayed before the first season we are monitoring this and if scientific evidence comes to light we will alter our client advise accordingly
• Some dogs need a first season - those that have been diagnosed with juvenile vaginitis by your vet need to wait until oestrogen levels are high enough to improve the vaginas immune system.  Those with a small inverted vulva will do better if you wait until oestrogen enlarges the vulva and can prevent problems of skin fold irritation when the dog is an adult