OVARY SPARING SPAY - GOOD OR BAD?

Studies have shown that large breed dogs that are spayed and neutered have a much higher incidence of cancer and joint problems. A 2013 study at U.C.Davis looked at two joint disorders and three cancers in Rottweillers - hip dysplasia, ACL tears, lymphosarcoma, hemangiosarcoma, and mast cell tumor. The results showed that rates of occurrence were significantly higher in both males and females that were neutered either early or late, compared to intact dogs. In response to this study, and others, veterinarians have started offering "ovary sparing spay" surgery instead of traditional spay and vasectomy instead of neuter. The spay procedure takes a little longer to perform and requires a longer incision to expose the entire uterus, as it must be removed completely, all the way to the cervix, to reduce chances of a stump pyometra. As long as all of the uterus is removed, there will be no bleeding during heats and no risk of uterine infection (pyometra).

Early spay has long been advocated as a way to avoid mammary cancer and pyometra (uterine infection). Mammary cancer is still a risk when the ovaries are left intact, but mammary cancer has only about a fifty percent risk of malignancy in dogs. Owners can do breast exams to feel for any early lumps or thickenings in the mammary glands and ultrasound can be performed to detect early nodules.

No good studies have been performed on smaller breeds of dog, but I have to believe the hormones are in the system for a reason. Presumably, estrogen related incontinence problems would not occur if the ovaries were left intact. ACL (anterior cruciate ligament) tears and degenerative joint disease, along with cancers might have decreased incidence.

The decision you make regarding the type of surgery performed should be discussed with your veterinarian. Obviously, waiting to spay requires vigilance so your young dog does not get bred on the first or second heat. I will only discuss waiting for maturity with responsible pet parents in my office.

Studies have not been performed in this regard for cats, but mammary cancer in cats has closer to 95% malignancy rate, so I would not recommend this procedure at this time. Cats are much more resistant to bone cancer and hemangiosarcoma and rarely have urinary incontinence issues.