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 Australian Shepherds.
While the paper isn’t perfect (more on that later), it does provide the first evidence for Australian Shepherds 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 | 0/28 (0) | 1/28 (3.57) | 0/29 (0) | 1/27 (3.7) |
| Male 6 – 11 months | 0/54 (0) | 1/55 (1.82) | 1/56 (1.79) | 2/53 (3.77) |
| Male 1 year | 0/20 (0) | 0/20 (0) | 0/19 (0) | 0/19 (0) |
| Male 2 – 8 years | 1/23 (4.35) | 1/23 (4.35) | 1/24 (4.17) | 2/23 (8.7) |
| Male Intact | 1/94 (1.06) | 1/92 (1.09) | 1/92 (1.09) | 3/92 (3.26) |
| Female < 6 months | 0/23 (0) | 1/23 (4.35) | 0/23 (0) | 1/23 (4.35) |
| Female 6 – 11 months | 1/55 (1.82) | 1/54 (1.85) | 0/54 (0) | 2/53 (3.77) |
| Female 1 year | 0/15 (0) | 1/15 (6.67) | 0/15 (0) | 1/15 (6.67) |
| Female 2 – 8 years | 0/38 (0) | 0/38 (0) | 0/38 (0) | 0/37 (0) |
| Female Intact | 1/76 (1.32) | 1/76 (1.32) | 2/77 (2.6) | 3/76 (3.95) |
| LSA | MCT | HSA | OSA | At Least One | |
| Male < 6 months | 2/28 (7.14) | 1/29 (3.45) | 0/29 (0) | 0/29 (0) | 2/28 (7.14) |
| Male 6 – 11 months | 1/56 (1.79) | 0/55 (0) | 0/56 (0) | 1/56 (1.79) | 2/55 (3.64) |
| Male 1 year | 0/20 (0) | 0/20 (0) | 0/20 (0) | 0/20 (0) | 0/20 (0) |
| Male 2 – 8 years | 1/21 (4.76) | 0/24 (0) | 0/23 (0) | 1/24 (4.17) | 2/21 (9.52) |
| Male Intact | 2/90 (2.22) | 1/93 (1.08) | 6/91 (6.59) | 0/93 (0) | 8/88 (9.09) |
| Female < 6 months | 0/23 (0) | 0/23 (0) | 0/21 (0) | 0/22 (0) | 0/20 (0) |
| Female 6 – 11 months | 2/54 (3.7) | 0/55 (0) | 2/55 (3.64) | 0/55 (0) | 4/54 (7.41) |
| Female 1 year | 0/15 (0) | 0/15 (0) | 0/15 (0) | 0/15 (0) | 0/15 (0) |
| Female 2 – 8 years | 0/39 (0) | 0/39 (0) | 1/38 (2.63) | 2/39 (5.13) | 3/38 (7.89) |
| Female Intact | 0/76 (0) | 0/76 (0) | 1/74 (1.35) | 0/75 (0) | 1/73 (1.37) |
UI was reported in 1% of the spayed females.
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 Australian Shepherd Spay & Neuter Times
There is minimal evidence that Australian Shepherd health problems are influenced by the age of neutering. Owners of either sex are therefore free to choose the age of desexing that suits them best.
Recommendation: between 6 and 12 months for males, and one year for females.
This allows for the general trend of later times with higher body weights. It is later with females as they will come into season at 7-9 months, and we want this to settle down completely before surgery.
This is so far the only science we have for the best desexing age in Aussie Shepherds. 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 also 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 Australian Shepherd at least, they’ve made the decision a lot easier.
Related: Best Desexing Age For 35 Breeds | Desexing Choices For Dogs | Costs Of Desexing
Have something to add? Comments (if open) will appear within 24 hours.
By Andrew Spanner BVSc(Hons) MVetStud, a vet in Adelaide, Australia. Meet his team here.
I think our Australian Shepherd puppy will grow to be about 60 pounds. He’s 7 months old, and we just had him neutered. I’m worried that he won’t have enough testosterone to help him mature correctly.
Hi Allyn. If you look at the data, you’ll see that, although it would have been better to go a bit later, the risks are quite low. For many years, dogs like him were desexed at six months of age, and the consequences were not severe in the vast majority.
Hi, we bought a house and an 11 – 12 year old Australian shepherd came with it. He’s a wonderful old guy. Super sweet, but he was never neutered. Is it too late to neuter him? What are the risks?
Hi Ceci. The big three are testicular tumours, prostatic enlargement (and secondary constipation) and perineal hernia. The first two are curable with desexing if caught early, the third is not. Having said this, plenty of entire males get through life without either of these three occurring, so the decision is yours.
I honored the no spay contact my Australian Shepherd breeder required and spayed my Aussie at 13 months after heat cycle. Didn’t ask why the delay for spaying, but she must have good reasons. General belief is spaying at 6 months is fine and alleviates breast cancer chances to zero.
Which is best?
Hi Barb. It’s hard to give simple answers, which is why I included as much raw data as possible in the article so you can make up your own mind. As I did not mention mammory cancer, you can be assured that the risk is still very low with spaying at 13 months of age.
Please tell I didn’t neuter our Australian Shepard to early. I asked the Humane Society they told me he was old enough. He was 17 weeks old
Hi Carolyn. Shelters need to work by different standards, so there’s nothing wrong with what you were told. Also, the risks of going a little early are very low.