https://www.avma.org/News/JAVMANews/Pages/100301g.aspx https://www.avma.org/News/JAVMANews/Pages/100301g.aspx "New research on the biology of aging in dogs sug

https://www.avma.org/News/JAVMANews/Pages/100301g.aspx https://www.avma.org/News/JAVMANews/Pages/100301g.aspx "New research on the biology of aging in dogs suggests a link between shortened life expectancy and ovary removal." "The study, published in the December 2009 issue of the journal Aging Cell, found that Rottweilers that were spayed after they were 6 years old were 4.6 times as likely to reach 13 years of age as were Rottweilers that were spayed at a younger age."