Brent LA, CA 3/23/2010 2:54:21 PM 1. The study itself appears to be a rehash of a study that was published back in 2003 - the same data was used but the emphasis in that study was on canine cancer. "Exceptional longevity in pet dogs is accompanied by cancer resistance and delayed onset of major diseases." No mention was made of ovary exposure as related to longevity even though the same Rottweiler data was used. 2. The dogs studied died between 1995-2000 - further indicating this was an old study - first used for a different purpose. 3. The major flaw in the 2009 study is the control groups of dogs used. They used one group aged 9-10 yrs. - and another group aged 13.3-14.3. The study only included 183 Rottweiler dogs in healthy home environments. We already know that the benefits of spaying include greatly decreased risk of breast & ovarian cancer. The average age of onset for breast & ovarian cancers in Rottweilers is generally younger than the control groups studied, thus all Rottweilers that died of breast or ovarian cancer at a younger age would have been excluded from the study. This would compare to taking a group of female smokers 90 years old and over - and concluding that cigarette smoking has no effect on women's health since they are still alive at 90. All the women who died of smoking related diseases at younger than 90 years of age (common) would not have been considered in the study. 4. There appears to be other factors that contributed to the longevity of the Rottweilers in the 13.3-14.3 age group. As a group they weighed less at 79-90 lbs. - versus the younger group that weighed 90-100 lbs. Also the older dogs were shorter. Studies have long shown smaller, thinner dogs live longer by two years on average. 5. The oldest Rottweiler group - 13.3-14.3 - had a considerably larger number of mothers that achieved exceptional longevity - showing a genetic link to their longevity. 6. The 2009 study greatly contradicts much broader previous studies on ALL breeds and MIXED breeds - in reputable journals that show unequivocally the spaying prolongs female dog's lives and that breeding shortens their lives. 7. The study is flawed also because he states that the average life expectancy of a Rottweiller is 9-10 yrs., when the majority of resources indicate it is actually 10-12 years - thus the "exceptional longevity" of 13 is not that extraordinary. Even more notable is the major cause of death he shows for in Rottweillers in the 9-10 yr. group is indeed cancer - 73% dying from it. 8. The study was originally completed to show that Rottweilers that lived past the age of 10 had a reduced risk for cancer. 73% died from it in his 9-10 year group and only 25% died from it in his 13.3 to 14.3 age group. This is the REAL information the study revealed - and the main thrust of the 2003 paper.