Elective pet surgeries are commonly done on specific breeds of dogs to achieve a certain look or on cats to stop clawing. Personally I find these procedures very unnecessary and it puts the animals through so much pain for almost no reason.
When you see an animal with a docked tail it doesn’t always mean it was done for elective reasons. Some animals are born with them already like that and some tails are docked for medical reasons. However it can cause communication and behavioral issues. Dogs talk with their tails and ears and a nub doesn’t say the same thing as a full tail can. It can lead to the dog being more aggressive and not as friendly to new people as an unaltered version of the same breed would be. Also because of the muscles that are connected to tails it can effect their digestion and how they defecate.
Ear cropping is basically making floppy ears stand straight up to a point. The dogs ears are cut and then bound with medical wrap to uphold their new shape. Usually it happens when the dog is still young so they grow with it, but the process takes quite a long time (4-8 weeks) and if not done right can have some serious complications such as infection and phantom pain. It has similar behavioral effects as tail docking with how dogs communicate and how their temperament can change. People also will preform this themselves for dog fighting which is easy to spot because of how botched it is.
Declawing a cat is when you remove their nails from their paws. This surgery is super painful for the cat and can cause some behavioral issues. A lot if not all military housing requires if you have a cat is has to be declawed, but most veterinarians refuse to do this procedure anymore. Removing a felines nails is like removing the very top of a persons finger. It can lead to infection, nerve damage, and an abnormal gait (which can cause back pain). Many cats are never the same after; they tend to become aggressive and or more fearful and can also lead to them not wanting to use their box anymore. Since they lose their main source of defense they can start biting more and become not as trusting of people anymore.