I'm a full-time advocate of neutering domestic animals whenever possible.
My logic is simple, if you have a pet or community animal, there's no reason for you not to neuter it. There's enough scientific data out there to prove the benefits of spaying to the animal itself and the community. Besides, unless for whatever reason you do want to breed (ughh) your animal, it is just a smoother, happier and longer life.
The reason I decided to speak about spaying was a case(image below) that was presented to us recently. Fufi, an 8-year-old Indian stray dog with two ulcerated mammary tumours. Her ears were notched meaning she was neutered whom the owners said was done at 6 months of age. But, keeping that in mind, we were a little doubtful whether it was a complete spay or not. To quote an article we had read:
Mammary tumors are more common in female dogs that are either not spayed or were spayed after 2 years of age. The risk of a dog developing a mammary tumor is 0.5% if spayed before their first heat (approximately 6 months of age), 8% after their first heat, and 26% after their second heat. Cats spayed before 6 months of age have a 7-times reduced risk of developing mammary cancer and spaying at any age reduces the risk of mammary tumors by 40% to 60% in cats.
Now, what I define as a complete spay is an ovariohysterectomy i.e. removal of both ovaries and uterus up till the cervix. Half spays or what I like to call them are just hysterectomies i.e. removal of only the uterus, which to me makes absolutely no sense! Yes, it achieves sterility in terms of the absence of an organ for implantation but you still have ovaries! The major producer of female hormones! This means that the female will still come into heat and show all its signs in addition to having other complications including ovarian cancer, cysts, or like above, uterine horn abnormalities. It seemed to be a uterine tumour/cyst which when cut released green purulent foul-smelling fluid. However, that was not the only thing abnormal, what I found inside were fully intact ovaries and horns. One horn was so deeply adhered and embedded in mesentery not to forget also cystic and purulent. There's more, just around the part, where the left ovary should be, was a large cystic structure so adhered to the abdominal fat, it was too risky to remove without causing severe bleeding and complications so I had to ligate and leave it inside in hopes that it will subside in time.
In my 3 full-time years of practice and some more time working with animals, I have not come across any complications after a spay when it was done the right way and by a learned and skilled Veterinarian.
So here my two-cents of advice :
For vets - Please do full spays, half spays make no sense. If you really want to, I would go for an ovariectomy, as this will still cause regression of the uterine body once removed and no major hormonal complications. But could still have the risk of developing postoperative stump pyometra.
For pet parents and animal caregivers - S'il Vous Spay. Before the first heat cycle and opt for a complete spay from a skilled veterinarian. Nothing will go wrong if done right.