Male and female Rottweilers spayed/neutered before 1 year of age have an approximate one in four lifetime risk for bone sarcoma and are significantly more likely to develop bone sarcoma than dogs that are sexually intact.
See this link for the abstract at PubMed. See this link for the complete study. From the abstract:
Endogenous gonadal hormone exposure and bone sarcoma risk.And no, it isn't just Rottweilers. From the essential report on spay/neuter health effects, by Laura Sanborn:
Cooley DM, Beranek BC, Schlittler DL, Glickman NW, Glickman LT, Waters DJ.
Department of Veterinary Clinical Sciences, Purdue University, West Lafayette, Indiana 47907, USA.
Risk for bone sarcoma was significantly influenced by age at gonadectomy. Male and female dogs that underwent gonadectomy before 1 year of age had an approximate one in four lifetime risk for bone sarcoma and were significantly more likely to develop bone sarcoma than dogs that were sexually intact [RR +/-95% CI = 3.8 (1.5-9.2) for males; RR +/-95% CI = 3.1 (1.1-8.3) for females]. Chi(2) test for trend showed a highly significant inverse dose-response relationship between duration of lifetime gonadal exposure and incidence rate of bone sarcoma (P = 0.008 for males, P = 0.006 for females). This association was independent of adult height or body weight.
Osteosarcoma (Bone Cancer)Yes, Laura Sanborn is a leader in the fight against mandatory spay/neuter. Her review of the literature is evenhanded — quite the contrast with California's AB 1634 supporters, who are past masters at misinterpreting [I'm being kind, here] all types of data. And no, there is simply no way to spin the science and come up with anything that makes osteosarcoma appear less of a risk for medium size or larger dogs subjected to early spay/neuter.
A multi-breed case-control study of the risk factors for osteosarcoma found that spay/neutered dogs (males or females) had twice the risk of developing osteosarcoma as did intact dogs.
This risk was further studied in Rottweilers, a breed with a relatively high risk of osteosarcoma. This retrospective cohort study broke the risk down by age at spay/neuter, and found that the elevated risk of osteosarcoma is associated with spay/neuter of young dogs. Rottweilers spayed/neutered before one year of age were 3.8 (males) or 3.1 (females) times more likely to develop osteosarcoma than intact dogs. Indeed, the combination of breed risk and early spay/neuter meant that Rottweilers spayed/neutered before one year of age had a 28.4% (males) and 25.1% (females) risk of developing osteosarcoma. These results are consistent with the earlier multi-breed study but have an advantage of assessing risk as a function of age at neuter. A logical conclusion derived from combining the findings of these two studies is that spay/neuter of dogs before 1 year of age is associated with a significantly increased risk of osteosarcoma.
The researchers suggest a cause-and-effect relationship, as sex hormones are known to influence the maintenance of skeletal structure and mass, and also because their findings showed an inverse relationship between time of exposure to sex hormones and risk of osteosarcoma.
The risk of osteosarcoma increases with increasing breed size and especially height. It is a common cause of death in medium/large, large, and giant breeds. Osteosarcoma is the third most common cause of death in Golden Retrievers and is even more common in larger breeds.
Given the poor prognosis of osteosarcoma and its frequency in many breeds, spay/neuter of immature dogs in the medium/large, large, and giant breeds is apparently associated with a significant and elevated risk of death due to osteosarcoma.
If you support mandatory spay/neuter laws like AB 1634 or the recently passed spay/neuter law in the city of Los Angeles, you are apparently willing to condemn many dogs to an agonizing disease and a drastically shortened life on the entirely baseless speculation that this might somehow help reduce the number of dogs and cats in animal shelters.
God forbid individual citizens should make medical decisions based on what's best for individual animals — right, Lloyd Levine? Tell us again how your determination to mandate a dramatically increased risk of canine osteosarcoma is really no different from telling people to buckle their seat belts.
Heartbreaking message posted in the Border Collie Boards In Memoriam section.
Dolittler post on amputation for dogs suffering from osteosarcoma. Nothing said about whether the Rottie was neutered — I'll ask.
Rottweiler Health Foundation.