Announcing a New Safer Alternative to Traditional Spaying.
Is It Safe to Leave the Uterus Behind?
"Yes it is. However, there are still plenty of veterinarians who continue to warn pet owners of the dangers of uterine infection and uterine cancer. To be blunt, this is nonsense." Karen Becker, DVM
http://healthypets.mercola.com/sites/healthypets/archive/2011/04/14/ovariectomy-safer-alternative-to-pet-spaying.aspx


Making a Rational Choice Between Ovariectomy (OVE- leaving the uterus) and Ovariohysterectomy (OVH-removal of uterus) in the Dog. A discussion of The Benefits of Either Technique, Bart Van Goethem, DVM
See Conclusion-
"OVH (removing the uterus) is technically more complicated, time consuming, and is probably associated with greater morbidity (larger incision, more intraperative trauma, increases discomfort) compared with OVE (leaving the uterus). No significant differences between techniques were observed for incidences of long-term urogenital problems, including endometritis/pyometra and urinary incontinence, makig OVE the preferred method of gonadectomy in the healthy bitch."
"... there is no benefit and thus no indication for removing the uterus during routine neutering in healthy bitches. Thus we believe that OVE should be the procedure of choice for canine gonadectomy."  Read the Full Report