I’ve had tetanus vaccines, and I have ten healthy children. It’s possible that a contraceptive element is being added (I might have read that ...), but there’s no indication in the developed world of a safe, permanent, contraceptive shot, and the demand for it would be immense.
With current technology the attempt to do that might have other unwanted side effects.
But again what you might loose on animals (or what you view as animals) might fall below what you would pass out to acknowledged people.