Updated July 28, 2022
Whether you call it neuter, spay, castrate or desex, the right time to get it done in dogs is a subject of much debate. This is because it varies from breed to breed. Recently, a study was published on the best age for neutering in West Highland White Terriers.
While the paper isn’t perfect (more on that later), it does provide the first evidence for Westies on choosing a time of desexing with the fewest health problems. The study compared dogs neutered at different ages for their rates of:
- hip dysplasia (HD), cruciate ligament injury (CCL) and elbow dysplasia (ED)
- lymphoma (LSA), mast cell tumour (MCT), haemangiosarcoma (HSA), osteosarcoma (OSA)
- urinary incontinence (UI)
All of these have been suspected to be linked with the age of neutering. Here’s what they found (only bold values are significant, my summary to follow):
| HD | CCL | ED | At Least One | |
| Male < 6 months | 0/5 (0) | 0/5 (0) | 0/5 (0) | 0/5 (0) |
| Male 6 – 11 months | 0/17 (0) | 0/17 (0) | 0/17 (0) | 0/17 (0) |
| Male 1 year | 0/4 (0) | 0/4 (0) | 0/4 (0) | 0/4 (0) |
| Male 2 – 8 years | 0/5 (0) | 0/5 (0) | 0/5 (0) | 0/5 (0) |
| Male Intact | 0/35 (0) | 1/35 (2.86) | 0/35 (0) | 1/35 (2.86) |
| Female < 6 months | 0/7 (0) | 0/7 (0) | 0/7 (0) | 0/7 (0) |
| Female 6 – 11 months | 0/16 (0) | 0/15 (0) | 0/16 (0) | 0/15 (0) |
| Female 1 year | 0/5 (0) | 0/5 (0) | 0/5 (0) | 0/5 (0) |
| Female 2 – 8 years | 0/14 (0) | 0/14 (0) | 0/14 (0) | 0/14 (0) |
| Female Intact | 0/28 (0) | 0/28 (0) | 0/28 (0) | 0/28 (0) |
| LSA | MCT | HSA | OSA | At Least One | |
| Male < 6 months | 0/5 (0) | 0/5 (0) | 0/5 (0) | 0/5 (0) | 0/5 (0) |
| Male 6 – 11 months | 0/17 (0) | 0/17 (0) | 0/17 (0) | 0/17 (0) | 0/17 (0) |
| Male 1 year | 0/4 (0) | 0/4 (0) | 0/4 (0) | 0/4 (0) | 0/4 (0) |
| Male 2 – 8 years | 0/5 (0) | 0/5 (0) | 0/5 (0) | 0/5 (0) | 0/5 (0) |
| Male Intact | 0/34 (0) | 0/35 (0) | 0/35 (0) | 0/35 (0) | 0/34 (0) |
| Female < 6 months | 0/7 (0) | 0/7 (0) | 0/7 (0) | 0/7 (0) | 0/7 (0) |
| Female 6 – 11 months | 1/16 (6.25) | 0/16 (0) | 0/16 (0) | 0/16 (0) | 1/16 (6.25) |
| Female 1 year | 0/5 (0) | 0/5 (0) | 0/5 (0) | 0/5 (0) | 0/5 (0) |
| Female 2 – 8 years | 0/14 (0) | 0/14 (0) | 0/14 (0) | 0/14 (0) | 0/14 (0) |
| Female Intact | 0/28 (0) | 0/28 (0) | 0/28 (0) | 0/28 (0) | 0/28 (0) |
There was a single case of UI in the females spayed < 6 months and in those spayed 6-11 months.
If this table makes no sense, it’s mostly because there are no abnormal findings. Have a look at this one for Golden retrievers as a comparison.
Summary: The Best Westie Spay & Neuter Times
There is minimal evidence that Westie health problems are influenced by the age of neutering. Females spayed early had a higher incidence of urinary incontinence but the numbers are far too small to be meaningful.
Recommendation: 6 months for both sexes
This is so far the only science we have for the best desexing age in Westies. Your vet, breeder or online group may have a different opinion based on their experience or personal beliefs. It’s perfectly reasonable to take their advice into consideration as well.
Problems With This Study
The authors do not mention the well-known increase in lifespan associated with desexing male and female dogs, which tends to counteract most concerns about specific cancers. The following comment in the paper is a clue that it might also have been true for this population:
Across all breeds the mean age of last entry in the record for neutered males was 5.5 years (range 3.71–6.54), for neutered females 5.7 years (range 4.21–6.97), for intact males 4.9 (range 4.15–7.11), and intact females 4.7 (range 3.41–6.32)
The study tries to also look at the rates of mammary cancer & pyometra in females, but cannot give an accurate assessment for two reasons:
- the mean ages listed above are far too young to pick up most cases
- pyometra and mammary cancer are rarely referred to university hospitals
Regardless of any concerns, the authors are to be applauded to bringing into focus one of the most common questions from dog owners. For the West Highland White Terrier at least, they’ve made the decision a lot easier.
Related: Best Desexing Age For 35 Breeds | Desexing Choices For Dogs | Costs Of Desexing
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By Andrew Spanner BVSc(Hons) MVetStud, a vet in Adelaide, Australia. Meet his team here.