When to spay or neuter your pet

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“Conehead” Birdie. Submitted photo

Our pandemic puppy, Birdie, is being a pest today. She’s a nine-month-old Irish setter who was spayed last week and doesn’t understand why she can’t go outside and run. It’s our turn to follow the post-surgery instructions and we are reminded of how painful it is for the pet and owner to get through the two weeks of restrictions. So far so good. She’s being a good girl with the cone and managing just fine.

Let’s start with the easy pet, cats. The rule of thumb is to “Fix Felines by Five” months. Most of the time cats come into their first heat cycle at six months of age. Both male and female cats should be sterilized at this time. This approach prevents unwanted litters and allows for normal growth and development. Waiting on neutering males may result in spraying urine in the house. Females spayed at five months are less likely to have mammary tumors later in life. Young cats recover very quickly from their surgeries and don’t require much aftercare.

Dogs are a different story. Veterinarians for decades had recommended spaying or neutering all dogs at six months of age. Most dogs have their first heat cycle at six-12 months of age. The smaller dogs tend to come into heat around six months and the larger dogs are later. Spaying at six months beat the heat, which is ideal because the risk of mammary cancer is greatly reduced. Neutering the males early helped to reduce the unwanted male behaviors that are reinforced over time if the dogs are left intact (mounting, aggression, marking). 

Then in 2013 a study at UC Davis was published with Golden Retrievers. Goldens are a popular breed with lots of health problems. The research showed that early spay/neuter in this breed increases the risk of several cancers (mast cell tumors, lymphosarcoma, hemangiosarcoma) and also may promote musculoskeletal issues (ACL disease, hip dysplasia). So now it isn’t so clear when to spay or neuter your puppy. This was one study on one breed but it has changed the recommendations. Obviously, more research is needed to understand what is best for all of our canine companions.

The best idea for now is to discuss the decision about when to spay and neuter your new dog with your veterinarian. There are lots of opinions. The American Animal Hospital Association recommends that dogs projected to be less than 45 pounds should have surgery at six months of age. Large-breed male dogs should be neutered between nine and 15 months after growth has stopped. When to spay a female over 45 pounds is anytime between five and 15 months depending on breed and disease risk. We spayed Birdie at nine months of age. She’s a small setter at 35 pounds. Luckily, she didn’t come into heat at six months and was able to finish her musculoskeletal development. They heal so quickly at this age but we have one week to go!