Neutering Effects in Retrievers

September 2nd, 2014

UC-Davis veterinary researchers did a study of the incidence of joint disorders and various cancers in neutered retrievers compared to those that were not neutered. The data suggests that the rate of cancers and joint disorders increases in neutered animals, and the effects are even more significant in Golden Retrievers than in Labrador retrievers. Further, they concluded that the age at which the animals are neutered also plays a role. Neutering before the age of 6 months, which is common practice in the United States, significantly increases the occurrence of joint disorders, especially in Golden Retrievers. Benjamin Hart, DVM, PhD, DACVB, a professor emeritus in the school, confirmed that Labrador retrievers are less vulnerable than Golden Retrievers to long-term health problems such as joint disorders and cancer.

The study was based on the health records of over 2500 male and female Labs and Golden Retrievers between the ages of 1 and 8. These particular breeds were chosen because they are physically and behaviorally very similar, and are popular as family pets and service dogs. The researchers also broke down the age at which they were neutered into the following four brackets: before the age of 6 months, between 6 and 11 months, between 12 and 24 months and between 2 and 9 years of age.

The three joint disorders focused upon were hip dysplasia, cranial cruciate ligament tear and elbow dysplasia. The researchers found that unneutered males and females of both breeds experienced a 5 percent rate of one or more joint disorders. In Labrador retrievers, that rate rose to 10% in those dogs neutered before the age of 6 months. Alarmingly, the findings concerning the impact of neutering on Golden Retrievers was much more severe. Neutering before the age of 6 months in these animals increased the incidence of joint disorders by 20-25%. The negative effects of neutering during the first year of a dog’s life are substantial. Neutering removes the ability to produce sex hormones, and especially in larger breeds, makes joints more vulnerable because of the delayed closure of long-bone growth plates. Male Golden Retrievers had the greatest increase of hip dysplasia and cranial cruciate ligament tear, while the increase for Labrador males leaned toward cranial cruciate ligament tear, and elbow dysplasia.

The data also revealed important differences in relation to the incidence of various cancers. The researchers focused on three types of cancer: lymphosarcoma, hemangiosarcoma and mast cell tumor. In unneutered dogs of both breeds, the occurrence of one or more cancers ranged from 3-5 %, except in male Golden Retrievers, where cancer was determined to be 11%. Neutering appeared to have little effect on the cancer rate of male goldens, but in female goldens, neutering at any point beyond 6 months elevated the risk of cancer to three or four times the level of unneutered females. Neutering in female Labradors increased the cancer incidence rate only slightly. This data concludes that the sex hormones produced by female Goldens specifically, has a protective effect against various cancers throughout most of the dog’s life. The decision to neuter should be carefully considered with regard to all Retrievers, but especially when pertaining to Golden Retrievers.