2013 study on adverse impact of neutering on health of dogs

[QUOTE=grayarabpony;6948882]
All you are doing is quoting from the paper and proving my point, that only Rottweilers spayed before one year of age showed a statistically significant increase in risk in bone cancer.

if you think the paper says something else you’re just incorrect.[/QUOTE]

“in summary, this study found that male and female Rottweilers with the shortest lifetime gonadal exposure had the highest risk for bone sarcoma…”

That is what the paper states.

YES. The ones SPAYED EARLY. They were the only ones with a statistically significant increased risk of cancer.

[QUOTE=grayarabpony;6948910]
Again, that study only shows benefit from not spaying early.[/QUOTE]

“…late neutering increases the rates of HSA to four times that of the 1.6 percent rate for intact females and to 5.7 percent for MCT, which was not diagnosed for intact females.”

Not statistically significant. Do you realize what a small number of dogs that is, and thus why those results are not statistically significant?

You seem determined NOT to understand the papers.

Not statistically significant. Do you realize what a small number of dogs that is, and thus why those results are not statistically significant?

You seem determined NOT to understand the paper.

Perhaps we should agree that we have different interpretations as to the conclusions the authors have drawn.

Figure 2 reveals that late-neutered females at 7.4 percent were diagnosed with HSA over 4 times more frequently than intact females with 1.6 percent and early-neutered females with 1.8 percent, both significant differences (RR = 6.10, 95% CI = 1.18, 31.37 and RR = 7.48, 95% CI = 1.79, 31.30

What part of “significant differences” do you not understand?

[QUOTE=Houndhill;6948952]
Perhaps we should agree that we have different interpretations as to the conclusions the authors have drawn.[/QUOTE]

Two people can’t have different interpretations of a statistical analysis of data in a scientific study.

Here, take a gander at this:

http://www.plosone.org/article/info:doi/10.1371/journal.pone.0055937.t004/largerimage

And, for hemangiosarcoma and mast cell tumor, there wasnt much difference at all between animals neutered early and intact animals. In addition, the overall percentage of animals with those conditions were quite low, less than 5 to 10 per cent.

Again, this does not refer to the data I have quoted above. These were indeed statistically significant results.

For female Golden Retreivers only, and which showed very little difference between spayed early and left intact! We’re talking 4 or 5 dogs here, in a group of 70, which is quite a small group. There could very well have been a genetic predisposition for those conditions in those particular dogs. The results may very well not be reproducible in a larger population.

These results were statistically significant.

It remains to be seen how these results would translate to other breeds. Different breeds have very different rates of cancer, of different types. For some breeds, hemangiosarcoma, lymphosarcoma, and osteosarcoma are not major causes of mortality. For other breeds, they are. For example, in my breed, Irish Wolfhounds, osteosarcoma is very prevalent, it is one of the top three causes of death. Therefore, anything that may affect its occurrence, such as gonadal hormones, is very important to understand, and is one thing we can control. In other breeds, osteosarcoma is very rare, so owners need not worry so much. Hemangiosarcoma and lymphosarcoma are also not rare in IWs so we have to worry about that too.

Goldens though are also at a relatively high risk for some types of cancer, and it is interesting that Hart et al raise the question about whether Golden service dogs should be routinely neutered.

Given the small sample sizes in the GR study, I still question whether the results are truly statistically significant. Or clincially significant. And yes, those results were also statistically insignificant between dogs neutered early and dogs left entire in that analysis.

And, the Rottweiler study did not show a benefit for spaying later than one year.

[QUOTE=Houndhill;6948916]
“in summary, this study found that male and female Rottweilers with the shortest lifetime gonadal exposure had the highest risk for bone sarcoma…”

That is what the paper states.[/QUOTE]

Statistical significance takes sample size into account.

I found this regarding the use of ratio ratios in statistical analysis, the one used in the Golden Retreiver study: the rate ratio is most suited to study events in a constant domain while the denominator -i.e. the population at risk- is very large.

Overall, the Golden Retriever paper showed a rather modest to zero benefit to keeping a dog intact, for a few conditions. I hope you have changed your mind regarding the Rottweiler study, lol.

It’s actually a pretty large study, 700 plus dog’s.

The study revealed that, for all five diseases analyzed, the disease rates were significantly higher in both males and females that were neutered either early or late compared with intact (non-neutered) dogs.

Specifically, early neutering was associated with an increase in the occurrence of hip dysplasia, cranial cruciate ligament tear and lymphosarcoma in males and of cranial cruciate ligament tear in females. Late neutering was associated with the subsequent occurrence of mast cell tumors and hemangiosarcoma in females.

In most areas, the findings of this study were consistent with earlier studies, suggesting similar increases in disease risks. The new study, however, was the first to specifically report an increased risk of late neutering for mast cell tumors and hemangiosarcoma.

Furthermore, the new study showed a surprising 100 percent increase, or doubling, of the incidence of hip dysplasia among early-neutered males. Earlier studies had reported a 17 percent increase among all neutered dogs compared to all non-neutered dogs, indicating the importance of the new study in making gender and age-of-neutering comparisons.

I was actually hoping you had changed your mind regarding the Rottie study lol!

Are you hard of reading?? I was referring to the GR study with the small sample sizes (especially in the late-neutered group).

And I don’t know how many times I’ve said that then study I linked to and the one referred to in the 2007 review that statistically significant benefits were seen only in dogs neutered early.

The numbers of the dogs in the GR study with those conditions were actually pretty small, and that method of analysis is not a good one with small samples.

And why on earth would I change my mind about the Rottie study? Do you want me to start making stuff up so I can change my mind? Because that’s what I’d have to do.

UC Davis Vet School is a pretty well respected research entity. I know one of the principle researchers, Ben Hart, and he is extremely well regarded. I would trust his statistical analysis of data.