[gemy]

Originally Posted by gemy

A retrospective cohort study published in Feb 1 2014 of Journal of the American Veterinary Association.

The link provided is an article by Dr Becker, who with-in the article provides the link to the actual study.

In line with the GR and Rottweiler studies, more confirmation of the health risks to spayed/neutered animals.

I leave it to the readers to look up the study.

Will Spaying/Neutering Increase Your Dog's Risk of Cancer?

Here is the link directly to the Viszlas study.

http://mercola.fileburst.com/PDF/Hea...izslaStudy.pdf


On the subject of mammary tumours here is one extract. If you click the link the full 12 page or so report is available to any reader.

The association between gonadectomy and various

neoplasms in dogs has been examined in several


studies.15–20 Mammary gland cancer is an important



condition in female dogs, with approximately 20% to


50% of the tumors being histologically malignant.33,34



It is commonly believed that gonadectomized female

dogs have a reduced risk of mammary gland cancer and

that the earlier a dog is gonadectomized, the lower the


risk.28,29,34,35 However, authors of a recent systematic review36



of all reports in peer-reviewed journals on the

associations among neutering, age at neutering, and

mammary gland tumors concluded that the evidence

that neutering reduces the risk of mammary gland neoplasia

is weak and not a sound basis for firm recommendations

on neutering because of limited evidence

and bias in published results.

I would try to copy and paste this report but right now my p.c. is telling me my disc is full

The above finding on Viszlas and no apparent association on age of spaying and relationship to mammary cancer is surprising to me. Most previous research I have read is for slight iincrease in incidence rate associated with spaying before first heat, spaying after first but prior second heat, but a minimal increate in risk/incident rate. How ever a sharp increase in unbred older intact females.

This study I need to look at more to see about pyrometra, which is imo, much more of a concern than mammary cancer is. Of course these two conditions affect predominately female dogs, or solely female dogs. And most studies indicate that pyrometra is rare in young females.

And as the study authors have said much more research is needed to be done not just for Viszlas but for all breeds.

It could very well be that there is a breed disposition to mammary cancer, as there seems to be for sarcomas, hemangiosarcomas, Von Willenbrands disease (which thankfully now there is a genetic test for). If you look at the report on cancers male/females you do not see mammary cancer delineated, and was included in the other types of cancer Mammary cancer was lumped in with all other cancers.

Other cancers including mammary and most specifically by breed type are only suspected, some breeds with strong suspicion that there is not only a breed disposition to, but an association with timing of s/n. So the first question to be answered by science is there a breed disposition to cancer? If so, what kinds and by what breed? Then what causes this breed disposition? Is it truly genetic? Some combo of genetics, nutrition, environment etc. Are all breeds or only certain breeds made more or less susceptible by judicious timing of a full s/n? Would it be better to use alternative methods of s/n to keep the sex hormones? For males, for females, for which breed types?

And having asked all the above questions, which will be decades in the answering, all we as breeders can go by is the best information at the time we need to make the decisions and or recommendations to our puppy owners. And all you can do as pet owners is to educate yourself as well for the breed (s) you own.

Some breeds are further ahead in answering these questions then others. Some answers perhaps mammary tumour and pyrometra is consistent across all or most breed types or sizes.

I await reading and posting new research and findings on this topic.