When to Neuter Spay or Desex Border Collies

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 Border Collies.

While the paper isn’t perfect (more on that later), it does provide the first evidence for Border Collies 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	0/9 (0)	0/8 (0)	0/8 (0)	0/7 (0)
Male 6 – 11 months	0/36 (0)	1/35 (2.86)	0/35 (0)	1/34 (2.94)
Male 1 year	1/9 (11.11)	0/11 (0)	0/11 (0)	1/9 (11.11)
Male 2 – 8 years	0/25 (0)	0/26 (0)	0/26 (0)	0/25 (0)
Male Intact	2/101 (1.98)	1/104 (0.96)	0/105 (0)	3/100 (3)
Female < 6 months	0/24 (0)	0/25 (0)	0/25 (0)	0/24 (0)
Female 6 – 11 months	0/37 (0)	0/37 (0)	0/37 (0)	0/37 (0)
Female 1 year	0/27 (0)	0/27 (0)	0/28 (0)	0/26 (0)
Female 2 – 8 years	0/23 (0)	0/24 (0)	0/25 (0)	0/22 (0)
Female Intact	1/88 (1.14)	1/87 (1.15)	0/88 (0)	2/87 (2.3)

Joint disorders. For ages 1 through 11 years and for each neuter period.

	LSA	MCT	HSA	OSA	At Least One
Male < 6 months	0/8 (0)	0/9 (0)	0/9 (0)	0/9 (0)	0/8 (0)‡
Male 6 – 11 months	2/33 (6.06)	1/36 (2.78)	1/35 (2.86)	0/36 (0)	*4/32 (12.5) ‡**
Male 1 year	1/11 (9.09)	0/11 (0)	0/11 (0)	0/11 (0)	1/11 (9.09)
Male 2 – 8 years	1/26 (3.85)	0/26 (0)	0/26 (0)	0/25 (0)	1/25 (4)
Male Intact	1/105 (0.95)	0/105 (0)	1/104 (0.96)	0/105 (0)	2/104 (1.92)
Female < 6 months	1/25 (4)	0/25 (0)	0/25 (0)	0/25 (0)	1/25 (4) †
Female 6 – 11 months	2/37 (5.41)	1/37 (2.7)	1/37 (2.7)	1/37 (2.7)	4/37 (10.81) †
Female 1 year	1/28 (3.57)	0/28 (0)	0/27 (0)	0/28 (0)	1/27 (3.7)
Female 2 – 8 years	0/23 (0)	1/25 (4)	0/25 (0)	0/25 (0)	1/23 (4.35)
Female Intact	0/84 (0)	0/87 (0)	0/88 (0)	0/88 (0)	0/83 (0)

Cancers. For ages 1 through 11 years, for each neuter period. Bold values indicate significance over the intact group. The asterisk (*) indicates when there was significance using the log-rank test, but no significance using the Wilcoxon test. The dagger (†) indicates significance over the intact group when the early groups (< 6 mo. and 6-11 mo.) are combined. The double dagger (‡) indicates significance over the intact group when the early groups (< 6 mo. and 6-11 mo.) are combined when using the log-rank test, but no significance using the Wilcoxon test.

UI was reported in only one spayed female.

Summary: The Best Border Collie Spay & Neuter Times

Border Collies in this study who were desexed at 6 to 11 months had a higher incidence of cancers.

Recommendation: 12 months of age for both sexes

This is so far the only science we have for the best desexing age in Border Collies. 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.

The decision may be based on other factors such as:

local neutering legislation
risk of male dog aggression to children
risk of pregnancy or reluctance to manage a female in heat
health problems associated with intact dogs

Problems With This Study

In the original paper, the authors appear to make some recommendations based on very limited evidence. I have published the original study data so you can see the actual numbers involved and decide for yourself.

The authors also 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 Border Collie at least, they’ve made the decision a lot easier.

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By Andrew Spanner BVSc(Hons) MVetStud, a vet in Adelaide, Australia. Meet his team here.