The kids will be out of school soon and many families will be thinking of adding another member to their household: a new puppy or kitten! There are a lot of questions that people should be asking, such as what breed, what breeder, what food, toys, and treats, but there is one very important question that needs to be talked about: WHEN SHOULD YOUR NEW FAMILY MEMBER BE SPAYED OR NEUTERED? This is the question we hope to shed some light on in this article. Being an educated pet parent is an important responsibility.

I want to get one fact out of the way before we go over the pros and cons of early spay/neuter: we are firm supporters in waiting to get a pet spayed or neutered until they are fully grown based on scientific evidence, which we will go over for you. This goes for dogs and cats. The pet needs their sex hormones in order to develop properly, especially in their joints. This does mean the larger the breed, the longer it will take for their bodies to develop, and therefore giant breeds should be given even more time before spaying or neutering them.

Now, let’s get into the PROS and misconceptions of early spaying/neutering…

Most people will be recommended to sterilize their puppy or kitten at 6 months of age. This is because this time is right before they would hit puberty. The surgery is easier for the veterinarian. It will also eliminate the risk of your pet getting diseases relating to the reproductive organs, such as testicular cancer and ovarian cancer. You may also be told that young animals handle drugs better than older pets. While this may be the case when comparing juveniles to senior pets, young pets do not have fully developed immune systems, and their kidneys and liver are not completely developed either. This means that they will have more difficulty expelling the drugs used for anesthesia and pain management. Pet parents will also be told that the typical ‘male’ dog behaviour will be reduced if they are neutered before they reach puberty. However, from studies and from personal experience, this is not always accurate. Some dogs react this way when neutered, but personality is personality and macho pets will persist if that is how a dog typically behaves. In a study done in dogs, those castrated under 5.5 months demonstrated more aggression and reactivity after being spayed/neutered than those intact.

The CONS of earlier spay and neuter…

The University of Florida did a study on growth plates in dog’s and cat’s joints and long bones. When comparing intact animals with those spayed or neutered young, the intact animals were smaller on average (when comparing similar breeds). This is because when you spay/neuter an animal, this cuts off important hormones involved in joint regulation and cartilage formation. Without these hormones the growth plates take longer to fuse, allowing long bones to grow more than intended. While the joints are still growing, they are not as strong as fully developed bones and are therefore more prone to damage and growth irregularity. Cutting of these hormones also decreases the pet’s metabolism, which causes the common weight gain associated with spaying and neutering. What this results in is the longer/bigger bones along with the weight gain means more weight on weaker joints. As I’m sure you are aware, this is a bad combination.

Expanding on joint health, let’s discuss hip dysplasia. Studies have shown that hip dysplasia occurs in roughly 10% of golden retrievers sterilized before one year of age. Those left intact or sterilized after 1 year only have a 5% occurrence of hip dysplasia. This means they are TWICE as likely to get hip dysplasia if spayed/neutered before they are done growing. There is an alteration in the hip/joint conformation with delayed growth plate fusion which results in the dysplasia. This also means that 5% of dogs not genetically prone to hip dysplasia will get it nonetheless due to early sterilization. The cause of the other 5% is up to speculation, and can have a number of contributing factors, such as genetics, environment, nutrition, exercise, etc. What I am trying to convey is that early spay/neuter can eliminate the factor of good genetics; dogs that are not prone to the deformation may get it anyways.

Studies have also shown that, even after taking out the factor of weight gain after sterilization, cruciate ligament tears are much more likely in spayed/neutered dogs. This is due to hormonal changes and slower fusing of the growth plates on the femur and tibia, which puts more strain on the cruciate ligament. With the cut off of sex hormones there is also decreased collagen concentrations, resulting in weaker ligaments. Dogs are not the only ones with these risk factors. Cats sterilized young have reported more fractures in growth plates than those intact or sterilized later in life.

Unfortunately, the list continues for the cons. Sterilized pets, especially those spayed or neutered young, are also 2-4 times as likely to get several types of cancer, including prostate cancer, lymphosarcoma (cancer of lymphocytes and lymph tissue), transitional cell carcinoma (cancer of the urinary tract), mast cell tumors (skin cancer), and osteosarcoma (bone cancer). Females spayed under 5.5 months of age also have under-developed vaginal canals and opening, which increases the risk of cystitis and urinary incontinence.

As you can see, there are many reasons to wait until your pet is fully developed until you spay or neuter them. However, we are aware that some pet owners do not have the option to wait. Maybe you do not have a fenced in back yard or your pet is difficult to keep separated when needed. There are many extenuating circumstances, and in these cases, it can’t be helped but to spay or neuter at 6 months of age. It is advised to give fish oil and a joint supplement to aid in their joint formation. Elk antlers are great since they help regulate joint growth. We have an unneutered male golden and a female Tibetan mastiff that is not spayed. Obviously, we do not want these two to breed. However, we do not find it difficult having the two of them since we just do not leave them alone together when our female is in heat and put pants on her or keep them separated when it is bedtime. We are a little bit spoiled since our golden is such an easy-going male, but it is an example that it is not impossible to be a responsible enough pet owner to keep an intact animal. If your veterinarian recommends spaying or neutering at less than 5 months of age, we encourage you to switch which vet you are going to. Try and find someone that is aware of the risks associated with early spay and neuter that will work with your concerns.