German shepherds are often the preferred breed for police and military work, and are also popular as service dogs and family pets. But joint disorders are a big concern.
Neutering or spaying German shepherds before 1 year of age triples the risk of one or more joint disorders—particularly for cranial cruciate ligament, or CCL, tears.
“Debilitating joint disorders of hip dysplasia, CCL and elbow dysplasia can shorten a dog’s useful working life and impact its role as a family member,” says lead investigator Benjamin Hart, professor emeritus in the School of Veterinary Medicine at the University of California, Davis. “Simply delaying the spay/neuter until the dog is a year old can markedly reduce the chance of a joint disorder.”
To prevent pet overpopulation or avoid unwanted behaviors. dog owners in the United States typically choose to spay or neuter their dogs prior to 6 months of age.
For the study, published in Veterinary Medicine and Science, researchers examined veterinary hospital records over a 14.5-year period on 1,170 intact and neutered (including spayed) German shepherd dogs for joint disorders and cancers previously associated with neutering. The diseases were followed through 8 years of age, with the exception of mammary cancer in females, which was followed through 11 years.
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The dogs were classified as intact (not neutered), neutered before 6 months, neutered between 6 to 11 months, or neutered between 12 to 23 months and 2 to 8 years. Joint disorders and cancers are of particular interest because neutering removes male and female sex hormones that play key roles in important body processes such as closure of bone growth plates.
The findings include:
- Seven percent of intact males were diagnosed with one or more joint disorders, compared to 21 percent of males neutered prior to 1 year of age.
- Five percent of intact females were diagnosed with one or more joint disorders, compared to 16 percent of females neutered prior to 1 year.
- Mammary cancer was diagnosed in 4 percent of intact females compared with less than 1 percent in females neutered before 1 year of age. (The occurrence of the other cancers followed through 8 years of age was not higher in the neutered than in the intact dogs.)
- Urinary incontinence, not diagnosed in intact females, was diagnosed in 7 percent of females neutered before 1 year of age.
“In addition to dogs suffering pain from joint disorders, the condition may also disqualify the dog as a working partner in military and police work,” Hart says. “We hope these findings provide evidence-based guidelines for deciding the right age to neuter a puppy to reduce the risk of one or more joint disorders.”
The Canine Health Foundation and donors to the Center for Companion Animal Health supported the research.
Source: UC Davis