And I know Wikipedia is not the be all and end all, but this is what it says about the history of docking and cropping:
“Historically, tail docking was thought to prevent rabies, strengthen the back, increase the animal’s speed and prevent injuries when ratting, fighting and baiting.[2] In early Georgian times in the United Kingdom, tax was levied upon working dogs with tails and so many types of dogs were docked to avoid this tax.[2] The tax was repealed in 1796 but that did not stop the practice from persisting.
In modern times, tail docking is done either for prophylactic, therapeutic or cosmetic purposes. For dogs who worked in fields, such as some hunting dogs and some herding dogs, tails could collect burrs and foxtails, causing pain and infection. Tails with long fur could collect feces and become a cleanliness problem, and particularly for herding dogs, longer tails could be caught in gates behind livestock[citation needed]. Many hunting dogs’ tails are docked to prevent them from becoming injured while running through thickets and briars while fetching hunters’ prey.
In dogs used for guarding property (such as Doberman Pinschers or Boxers), docked ears are thought to make the breed appear more ferocious; hanging ears are reminiscent of the naturally droopy ears of puppies, looking more cute than dangerous. Cosmetic docking is also done to meet breed registries standards.
For dogs with tail injuries that cannot be treated sufficiently with basic medical treatment, the tail can be docked to remove the damaged portion.”
Supposedly docking tails and cropping ears was done as far back as Roman times, in part to avoid untreatable infections in tails and ears injured during the hunt or other activity. I know that certain dogs (Cocker Spaniels for example) are known to have a great risk of ear infection due to the long and pendulous external ears and I have known a few who have had their ears shortened to reduce such infections.
One example is that of the Great Dane:
“These big guys were originally used for boar hunting. A Dane is taller than a wild boar, but the boar was tall enough to grab the dog’s ear because Danes naturally have long, floppy ears. Many dogs had their ear or ears ripped off by the attacking swine, which led to infections and scars, not to mention a funny-looking one-eared dog in many cases.
The solution? Cut the ears shorter. Then the prey would be unable to reach the dog’s ears. The practice caught on, and over the years, it was refined. Dog owners began to prefer the sleek look it gave their animals, so even nonhunting dogs were subjected to ear cropping.”
Fighting pit bulls generally are docked and cropped because it 1) makes them look “meaner” and 2) gives fewer mouth-holds to competitors in the fight ring.
There was one other aspect to cropping and docking. For a while folks believed Lamarck’s thoughts on inheritance of traits, that characteristics that were acquired during the lifetime of an organism were passed on to its offspring. Thus a breeder wanting to create a line of dogs with short tails would have docked the tails of his breeding dogs, believing that the trait of having a short tail would then be passed on to the offspring. But then along came Darwin and Mendel and that theory went out the window.
In any case, I don’t dock the tails or crop the ears of any dogs that live with me or pass through my hands. Some have naturally short tails or ears that stand up while others have long tails and floppy ears.
It is true that there are times my husband wishes American Bulldogs were born with short tails like their cousins the English Bulldogs, because our dog’s tail is a lethal weapon that swings just about at crotch height. But we don’t agree with subjecting any of our pets to unnecessary surgery. And the pain eventually passes.