When Should I Have My Dog Neutered? The Answer Is Not Straightforward
In brief
Current studies show the ideal age for neutering depends on breed, size and sex. UC Davis data often recommend later neutering for large breeds.
Many dog owners in the Basel region ask themselves exactly this question. The commonly heard advice to neuter a dog either before or after the first season sounds simple, but frequently falls short. Current scientific studies – including large population-based investigations from UC Davis – show that the health implications of neutering depend strongly on age, sex and in particular breed. There is therefore no universally optimal age for neutering.
Large Breeds: The Most Informative and Clearest Data
The most reliable insights come from medium and large breeds, where joint diseases and certain cancers occur frequently enough to reveal meaningful patterns. In breeds such as Golden Retrievers, Labrador Retrievers and German Shepherd Dogs, neutering before physical maturity increases the risk of cruciate ligament rupture, hip dysplasia and, in some cases, cancers such as lymphoma or mast cell tumour. Delaying neutering until after skeletal growth is complete – typically between 11 and 23 months of age, depending on breed – can substantially reduce these risks.
Early Neutering Can Carry Specific Risks
The studies also highlight cases where early neutering may be disadvantageous. Female Rhodesian Ridgebacks, for example, had a higher risk of mast cell tumours when neutered very early. Similar patterns emerge across several breeds, suggesting that the timing of hormone removal interacts with breed-specific susceptibilities.
Small Breeds: Limited Evidence, Limited Conclusions
Small breeds such as Shih Tzus or Shetland Sheepdogs appear in the UC Davis tables, but the evidence base is thin. Because small dogs rarely develop the joint diseases or cancers included in these analyses, the datasets often lacked sufficient numbers to identify clear patterns. Where no elevated risk was identified, this generally means the sample size was too small – not that a particular neutering age has been shown to be definitively safe.
Why Early Neutering in Small Dogs Is Still Recommended
Where strong medical evidence is absent, early neutering in small dogs is often recommended for practical rather than health reasons: to prevent unwanted pregnancies, avoid problems related to seasons, and for other management considerations. These are legitimate arguments, but they should not be confused with evidence that early neutering is medically optimal.
Conclusion: Tailored Decisions Are Best
Research consistently shows that neutering is not a one-size-fits-all decision. The clearest data exist for large breeds, and they often benefit from later neutering. Some females of specific breeds should avoid very early neutering. For many small breeds, reliable evidence is simply lacking – meaning decisions depend more on lifestyle, behaviour and owner priorities.
The most responsible approach is individualised advice – based on breed- and sex-specific evidence where available, and guided by practical circumstances when evidence is limited.
Please do not hesitate to get in touch if you would like to discuss neutering or spaying your dog.
Source: UC Davis – How to identify when a dog should be spayed or neutered