I don't care about any research that claims that unaltered animals are healthier. The fact that
2.7 million healthy, adoptable cats and dogs—about one every 11 seconds—are put down in U.S. shelters each year. That alone ends any debate for me regarding not altering ALL pets. Often these animals are the offspring of cherished family pets. Spay/neuter is a proven way to reduce pet overpopulation, ensuring that every pet has a family to love them.
People are just not responsible when it comes to pet ownership and doing basic preventative care such as vaccines, monthly heartworm preventions and a yearly visit to the vet. What makes anyone think that keeping unaltered animals is a wise decision is beyond me.
I would much rather see an altered pet be loved and have a possibility of some type of health issue down the road than a shelter full of cast off unwanted animals awaiting their death sentence.
Sure if you are a responsible breeder and take your responsibility seriously then I don't see a problem with not altering. But we all know "breeders" that have oops matings. People that come to YT for medical advice instead of vetting properly or looking for reason not to alter their animals will take this information and run with it for their own justification.
I firmly believe that all pets should be alter and not contribute to the overpopulation of animals in this country.