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. 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 Dobermans 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.
Docking of the tail and ears are both procedures which have been subject to controversy in recent times. Proponents state that the procedures are not significantly painful and can prevent future health problems that cause more pain and risk of infection than the docking procedure. Proponents believe that docking done almost immediately after birth ensures that the wound heals easily and properly, claiming that whatever little pain the procedure cause is a worthwhile trade off.
Docking of less than 10-14 days old puppies are routinely carried out by both breeders and veterinarians without anesthesia. Opponents of these procedures state that most tail dockings are done for aesthetic reasons rather than health concerns and are unnecessarily painful for the dog. They point out that even non-working show or pet dogs are routinely docked. They argue that in breeds whose tails have been traditionally and routinely docked over centuries, such as Australian Shepherds, little attention is paid to selectively breeding for strong and healthy tails. As a result, tail defects that docking proponents claim makes docking necessary in the first place are perpetuated in the breeds. They point out the many breeds of working dogs with long tails that are not traditionally docked, including English Pointers, Setters, Sheep dogs and Foxhounds.
Robert Wansborough argues in a 1996 paper that docking dogs' tails puts them at a disadvantage in several ways. Firstly, Wansborough argues that dogs use their tails actively in communicating with other dogs (and with people); a dog without a tail might be significantly handicapped in conveying fear, caution, aggression, playfulness, and so on. In addition, certain dog breeds use their tails as rudders when swimming, and possibly for balance when running, so active dogs with docked tails might be at a disadvantage compared to their tailed peers.
Wansborough also investigates seven years of records from an urban veterinary practice to demonstrate that undocked tails result in less harm than docked tails.
Critics point out that kennel clubs with breed standards that do not make allowance for uncropped or undocked dogs put pressure on owners and breeders to continue the practice. Although the American Kennel Club (AKC) says that it has no rules that require docking or that make undocked animals ineligible for the show ring, breed standards for many breeds puts undocked animals at a disadvantage for the conformation show ring. For example, the breed standard for boxers recommend that an undocked tail be "severely penalized. The AKC position is that ear cropping and tail docking are "acceptable practices integral to defining and preserving breed character and/or enhancing good health.
Today, many countries consider cropping and docking to be cruel or mutilation and ban it entirely. In Europe, the cropping of ears is prohibited in all countries that have ratified the European Convention for the Protection of Pet Animals while some countries that ratified had made exceptions for tail docking.
In England and Wales, ear cropping is illegal and no dog with cropped ears can take part in any Kennel Club event (including agility and other nonconformation events). Tail docking is also illegal, except for a few working breeds; this exemption applies only when carried out by a registered veterinary surgeon.
The Royal College of Veterinary Surgeons (RCVS), the regulatory body for veterinary surgeons in the United Kingdom, has said that they consider tail docking to be "an unjustified mutilation and unethical unless done for therapeutic or acceptable prophylactic reasons". In 1995 a veterinary surgeon was brought before the RCVS disciplinary council for "disgraceful professional conduct" for carrying out cosmetic docking. The vet claimed that the docking was performed to prevent future injuries and the case was dismissed for lack of evidence otherwise. Although cosmetic docking is still considered unacceptable by the RCVS, no further disciplinary action has been taken against vets performing docking.
In March 2006, an amendment was made to the Animal Welfare Bill (now the Animal Welfare Act 2006) which makes the docking of dogs' tails illegal, except for working dogs such as those used by the police force, the military, rescue services, pest control and those used in connection with lawful animal shooting. Three options were presented to Parliament with Parliament opting for the second:
Those found guilty of unlawful docking would face a fine of up to £20,000, up to 51 weeks imprisonment or both.
In Northern Ireland legislation regarding docking has not yet been drawn up. It is therefore still legal.
In Scotland docking of any breed is illegal. The Animal Health and Welfare (Scotland) Act 2006 contains provisions prohibiting the mutilation of domesticated animals.