by Laura J. Sanborn, M.S.
The stats quoted by your vets for mammary cancer risk and spaying are NOT correct. MANY vets — perhaps nearly all of them — misquote the landmark research study that led to these erroneous claims. Probably because almost none of them have actually read the published research report. Instead, they keep repeating the same misunderstanding that others have made rather than going to the original source. Here is actual research report that is the source of all of these false claims about mammary cancer risk and spaying. Table 4 is the part that gets misquoted into the false claims your vets mentioned. [http://saveourdogs.net/wp/wp-content/uploads/2010/05/Schneider-Dorn-Mammary-Cancer.pdf]
More info
http://www.naiaonline.org/uploads/WhitePapers/LongTermHealthEffectsOfSpayNeuterInDogs.pdf