[gemy]

Originally Posted by pstinard

For me, this is the worst aspect of the vizsla study:

The data was collected though anonymous questionnaires completed by owners, often years after the events being asked about, and there was no way to confirm the accuracy or validity of these reports.

Accurate data collection is the most critical part of any study. If you have questionable data, then the results and conclusions are questionable. I almost can't believe this, but here is a quote directly from the vizsla study itself:

Procedures—Data on demographics, gonadectomy status, and age at diagnosis of disease or disorder were obtained with an anonymous online survey and analyzed.

Anonymous online surveys can be completed repeatedly in order to purposefully skew results. A good chunk of the discussion section is devoted to discussing the inherent flaws of this study, and their overall conclusion is that more research is needed on the effects of neutering in dogs. I agree that more research is needed, but I'm afraid that a lot of people will come away thinking that the results (Dogs gonadectomized at ≤ 6 months, between 7 and 12 months, or at > 12 months of age had significantly increased odds of developing mast cell cancer, lymphoma, all other cancers, all cancers combined, and fear of storms, compared with the odds for sexually intact dogs) are scientifically valid, when they are not.

Data collection—Data on estimated risk and age of



diagnosis of mast cell tumor, hemangiosarcoma, lymphoma

or lymphosarcoma, all other cancers, and all cancers

combined as well as estimated risk and age at diagnosis

of behavioral problems were obtained for Vizslas from


a survey conducted on that breed in 2008.1 The survey



was designed by statisticians at the West Chester Statistics

Institute and administered via an anonymous online

questionnaire at a site hosted by West Chester University

Internet Presentations Group. There was a direct link to

that site from the Vizsla Club of America website, and

the survey was advertised in a variety of email lists, websites,

magazines, and newsletters to which Vizsla owners

would have access. Responses were allowed to be posted

between January 21 and December 15, 2008.


I was looking at this method of collection. And it seems like this would be a grade school error and not what appears to be institutes/professionals in the design and administration of an on line survey.
I am pretty sure there are ways to do an on line survey and keep the indentity of the owner/kennel anonymous and still prevent multiplicity of entries for the same dog/person, etc.
After all there are some regions here that allow on line voting for elections! For sure they have figured a way to insure only one vote for one person.

The SkepVet has done one such review of this study, surely there will be more experts contributing their own opinion on the research methodology etc.

And maybe an opportunity for the authors of the study to comment or clarify questions with response to on line survey methodology.

Data integrity and collection is a very key point. If the folks who are owners of Viszlas who also financially contributed to this study, I propose they would be pretty carefull about their reporting. After all they want some answers and were willing to fund in part this study. And they would have access to their own vet records to "refresh" their memory. The age of death of a pet is hardly something one easily forgets, nor if they had cancer. If as argued people were incentivized to complete this survey, and by that I mean, they have a deep and abiding passion for the overall health of their breed, then what pray tell would be the motive to skew the results? To knowingly submit bad information. After all they will likely also be the ones to fund further research into Viszlas.

To argue as the SkepVet has done, that Viszlas might not represent the whole dog population is quite frankly obvious. It was a unibreed study, and designed to be a unibreed study to answer specific questions and start to build a body of research on Viszlas.

As a matter of note I also find it quite surprising, that none of the studies I have read in recent years, go back to compare their results to the "hallmark" studies that must have been done on "all breeds" that supported a veterinary position of s/n about six months old, and the risks across all breeds for many of the health concerns that are talked about if you don't do by six months old.

Another argument made can and will be made against any study every designed here in North America. If the fact that 80% of our dogs are neutered then if you limit the study to N.A only, intact animals will always represent only a fraction of the total dog population. And likely those animals in part will be used for breeding and or for sporting, hunting, and or performance dogs. Not your "usual" pet.

It is a fact that to find for many breeds enough intact animals to participate in studies is very difficult. They will come mainly from organizations like performance/obedience/protection and or from breeders. I do agree with the SkepVet in that a likely true assumption is that we take prime care of our athletes and our dogs used for breeding. Always of course excepting the puppy mills (which I hardly think would contribute to breed surveys) and bybers who likely would not as well.

If I put aside for one moment the data collection integrity etc, I have a problem with only having spay/neuter category greater than 1 yr old. This category must then include retired breeding dogs, and or dogs who were held for breeding but never bred for a variety of reasons. Most breeders will not s/n before 1yr old, in almost all dog breeds. But they will retire females and spay them at 4 or 5 or 6 yrs old. Males not so much, although some do get neutered for a specific health problem if one does occur. In the dog performance sport world for large breeds, many females will not get bred, but will get spayed at or after 18months old. Now for Vizsla females that might not hold true if indeed their incidence of ED HD etc is only at 9% which I find surprising.

Just some thoughts on this.






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