This traditional timing for desexing has been reviewed over the last few years, as all long-standing policies should be, and subjected to close examination as to whether the date is best for the patient. We tend to desex from 4 months of age.
Much has been written about purported risks of desexing, especially of desexing young. Let’s look at some of the evidence.
There is much less time pressure on male dogs to be desexed young. It may prevent or reduce roaming behaviour, and in that sense is best done before this behaviour starts or very soon thereafter. We recommend castration from 4 months of age, but it can be delayed longer if required, especially if roaming behaviour is not yet an issue.
Female dogs are a completely different story due to the enormous benefit of early desexing on mammary cancer risk. Statistically, this completely outweighs the small increase in the risk of other conditions and represents a very significant health benefit. We recommend desexing before the first heat, so normally around 4-5 months of age.
Female cats frequently come in heat before 6 months of age, which results in stray tomcats arriving at your house. We recommend speying at 4-5 months of age.
Male cats left entire present a huge problem in terms not only of producing unwanted pregnancies but especially with the fighting behaviour that spreads diseases such as Feline Immunodeficiency Virus (FIV). We recommend male cats are castrated at 4-5 months of age.
Paul Eason BVM&S MANZCVS (Surgery; Emergency and Critical Care Medicine)