Talking With Pet Doctors

Effects Of Early Spaying And Neutering

by Christy Adams

Choosing to spay or neuter your pet is one of the most important decisions you can make for them. Spaying and neutering prevent unwanted pregnancies and reduces the number of homeless animals populating shelters. Overpopulation of stray animals can be a nuisance to livestock, pets, and humans. Strays may also carry diseases and parasites that can spread to other animals and humans.

Sterilization can also benefit your pet's health and behavior. Spaying helps to prevent ovarian, uterine, and mammary cancers in females and keeps them from having heat cycles. Neutering alleviates negative behaviors due to hormones such as some forms of aggression and marking territory with urine.

For many years it has been the standard practice to sterilize cats and dogs at six months of age or older.  However, spaying or neutering animals at a younger age may be more effective in preventing unwanted litters.  Early spay and neuter can be performed on kittens and puppies between 6 and 14 weeks old. Animals that are spayed or neutered at a young age will benefit from the positive effects of the procedure the same as older veterinary patients.

However, in some animals there may be some negative long-term effects to early sterilization. When the gonads are removed, the animal's body no longer produces certain hormones associated with those organs. These chemicals effect the animal's normal growth processes, which can result in a delay in the closure of growth plates in the long bones of the legs. The delay in closure of the growth plates allows the leg bones to continue growing for a longer period of time compared to the growth pattern of animals sterilized at an older age.

In some dog breeds, this delay has been linked to joint disorders. Data collected from male and female Golden Retrievers showed that 27 percent of males neutered before 6 months of age developed joint disorders, compared with 14 percent of males neutered between 6 and 11 months old. Twenty percent of females spayed prior to 6 months had joint disorders, while only 13 percent of dogs spayed older than 6 months had similar issues.

Large breeds of dogs such as Golden Retrievers, Great Danes, and Rottweilers have a greater tendency to develop osteosarcoma, a type of bone cancer. For males, the cancer rate increases for animals neutered before they are one year old. According to the Cummings Veterinary School at Tufts University, dogs neutered after their first year of life may have a reduced risk of getting osteosarcoma. If you have a large-breed puppy, talk with your pet's veterinarian about the best age to schedule neutering.