Tail docking is defined as the removal of part of a healthy tail from a healthy dog. Traditionally, this procedure was routinely performed in a number of specific breeds including Boxers, Rottweilers and Dobermans, as well as in many Spaniel and Terrier breeds. Puppies are usually tail docked at less than 5 days of age, and a varying amount of the tip of the tail is removed, depending on the breed, normally by using a scalpel blade or nail cutters. In some countries, tail docking is carried out by breeders or other lay persons rather than by vets; in others, only vets are legally permitted to perform this surgery. When performed by vets, a general anaesthetic or analgesic may be administered.

So why are dogs’ tails docked? The Council of Docked Breeds, a UK-based organisation set-up ‘to protect the freedom to choose the tail docking option’, says that docking is performed ‘to avoid damage to the tail in heavy vegetation and thick brambles, or down holes; for hygiene (avoiding faecal fouling with potential for maggot infestation), and to maintain breed standards (and the genetic pool, otherwise some breeds could be lost forever)’ (Council of Docked Breeds, 2010a). Some, but not all, of these reasons sound as if they may be of benefit to the animal concerned; we will return to this issue when discussing ethics in a later section.

Laws on tail docking vary between countries: while legal in the United States, tail docking is illegal in most European countries, unless medically indicated (Neumann, 2008). Although the procedure is legal in Canada (with the exception of Newfoundland), veterinary medical associations in a number of provinces do not permit their members to perform it. Exceptions to legal bans are made for working dogs in some countries, such as England and Wales but not Scotland (British Veterinary Association, n.d.), Denmark (Justitsministeriet, 1991) and Germany (Council of Docked Breeds, 2010b). The definition of a ‘working dog’ in England and Wales is tightly controlled, and veterinary certification is required; the dog must be docked before it is 5 days old and must also be microchipped. However, this exception for working dogs is difficult to police, as there is no guarantee that dogs once docked will ultimately be used as working dogs.

Debarking (devocalising) is a surgical procedure that involves removing a dog’s vocal cords under general anaesthetic. It is performed mainly to prevent nuisance noise, but sometimes also to create silent attack dogs.

Debarking is banned in the United Kingdom and other European countries, but is permitted in most states of the United States other than New Jersey, while Ohio restricts the surgery to dogs not considered ‘vicious’. The American Veterinary Medical Association (AVMA, 2013) recommends that the surgery only be done ‘as a final alternative to euthanasia after behavioural modification to correct excessive vocalization has failed and after discussion of potential complications from the procedure with the owner’.

Declawing (onychectomy) involves amputation of a cat’s distal phalanges (the last bone in the toe) of the front paws, usually simultaneously, to prevent the cat scratching (furniture or people). The amputations may be performed by using a scalpel, guillotine or laser. An alternative technique involves cutting or removing part of the deep digital flexor tendon of each toe (tendonectomy or tenectomy). This is a less invasive procedure that results in the claws remaining retracted (limiting the cats ability to scratch), but the claws become thick and brittle, and must be trimmed regularly.

Patronek (2001) estimates that 14.4 million of 59 million owned cats (approximately 24.4%) in the United States are declawed, and quotes other studies reporting between 19.6% (Morgan & Houpt, 1989) and 45.1% (Pollari & Bonnett, 1996). Declawing is often performed along with neutering, when the animal is 6–8 months old. It requires a general anaesthetic, application of a tourniquet (a constricting device used to control blood supply to an extremity for a period of time), and post-operative bandaging of both front paws.

Declawing and tendonectomy are illegal in more than 25 countries (including the United Kingdom and other European countries, Australia and New Zealand, Brazil, and Israel), but are legal, and widely performed, in the United States. The American Veterinary Medical Association does not recommend tendonectomy, but maintains that declawing should remain an option, but that it should be considered ‘only after attempts have been made to prevent the cat from using its claws destructively or when its clawing presents an above normal health risk for its owner(s)’ (AVMA, n.d.b).

The surgery that seems most likely potentially to offer direct health benefits to individual animals is tail docking. The argument, made largely in the case of working dogs (i.e. dogs that are not only, or not primarily, kept as companions), is that pre-emptive tail docking can prevent or limit the risk of painful injuries to dogs’ tails. However, evidence to support this argument is mixed.

Houlton (2008), for instance, looked specifically at gundogs, and found that for Springer Spaniels and Cocker Spaniels, there was a highly significant association between tail injuries and undocked dogs. A subsequent large study by Diesel et al. (2010) reported 281 tail injuries in a general population of 138,212 dogs. Within specific breed groups, Spaniels, Greyhounds, Lurchers and Whippets were at significantly higher risk of tail injury compared to Labradors and other Retrievers, yet of these, only Spaniels are traditionally docked. Most tail injuries occurred in the home, usually due to trapping the tail in a door, rather than when the dogs were working (as the legislation in the United Kingdom, for instance, is designed to address). The results also indicated that while dogs with docked tails were significantly less likely to sustain a tail injury, approximately 500 dogs would need to be docked in order to prevent one tail injury.

More recently, two linked studies, funded by the Scottish Government, investigated the prevalence of tail injuries in dogs in Scotland. In the first study, Lederer, Bennett & Parkin (2014) collected data by Internet questionnaire from owners of working dogs used during the 2010/2011 shooting season. They found that 13.5% of 2860 working dogs sustained at least one tail injury (nearly 42% of these dogs sustained two or more tail injuries, and 13.2% sustained four or more tail injuries). Spaniels and Hunt Point Retrievers (HPRs) with undocked tails were at greatest risk: 56.6% and 38.5% of undocked dogs of each breed, respectively, suffered at least one tail injury. The degree of docking (one-third, one-half or shorter) made no statistically significant difference to the likelihood of injury. The authors noted that while any benefit from docking would be likely to be sustained for the number of years that the dog was worked, docking as a puppy does not entirely remove the risk of subsequent tail injury. The authors also acknowledged potential bias in the study, which was publicised through country sports associations, known for their opposition to the complete tail-docking ban in Scotland.

In the second study, records from 16 veterinary practices in Scotland were retrospectively searched to identify the prevalence of more ‘severe’ tail injuries in working and non-working dog breeds between 2002 and 2012 (Cameron et al., 2014). Severe injuries were defined as those deemed by owners to require veterinary treatment; the overall prevalence was 0.59%, with significantly more injuries in working breeds (0.9%) compared to non-working breeds (0.53%). Within working breeds, Pointers and Setters were most likely to sustain a tail injury requiring veterinary attention (1.69%). Tail injuries severe enough to require amputation (0.12%) were significantly more common in working breeds (0.19%) than in non-working breeds (0.09%). Data was also available from eight practices for tail injuries in Spaniels before (April 29, 2007) and after the introduction of the tail-docking ban. Tail injuries were seen in 14/2607 Spaniels (0.54%) before the ban, and 36/2942 spaniels (1.22%) after January 2009: the odds of suffering a tail injury were 2.3 times greater after the ban.

However, the number of dogs that must be docked to prevent a tail injury seems high, even though both Scottish studies estimate lower numbers than the 500 proposed by Diesel et al. (2010). To prevent a tail injury in working breeds, Lederer et al. (2014) suggest that between 5 and 54 puppies across all working breeds – or in the case of Spaniels or HPRs, between 2 and 18 puppies – would have to be docked. To prevent a ‘severe’ tail injury, Cameron et al. (2014) calculated that approximately 232 puppies across the working breeds – or between 81 and 135 Pointer/Setter, HPR or Spaniel puppies – would need to be docked. To prevent one tail amputation in Spaniels, 320 Spaniel puppies would need to be docked.

The authors of both Scottish studies propose that it may be appropriate to consider changes to the current legislation for specific breeds of working dogs, suggesting that the difference in risk is most likely due to the different tail conformation, and the fact that the breed groups work in very different terrains (most ‘worst tail injuries’ occurred during ‘rough’ or ‘driven shoots’ while dogs were in ‘cover’ or ‘woodland’). However, with the exception of Spaniels, most of the breeds identified in the aforementioned studies as being most at risk of tail injuries (Greyhounds, Lurchers, Whippets, Pointers, Setters and Retrievers) have historically not been docked.

While there may be some benefits to some dogs of being tail docked, potential benefits seem to be much less clear in the case of the other three surgeries. Although there are anecdotal claims that ear cropping reduces ear infections and makes dogs’ ears less vulnerable to tearing, no systematic evidence of health benefits from ear cropping has been uncovered. There do not appear to be any direct health benefits to the animals concerned from debarking and declawing either. But do these practices provide indirect benefits?

Convenience surgeries raise interesting questions about the attachment between humans and their animal companions. For example, preventing barking and scratching – perceived as problems by some owners – by devocalisation and declawing, although offering no direct health benefits for the animals, may result in a better relationship between the owner and the animal. Consequently, the animal may have a better life; for instance, fewer punishments for anti-social behaviour, and a reduction in the likelihood of the animal being abandoned, rehomed or euthanased.

The American Kennel Club (2010) states that:

debarking is a viable veterinary procedure that may allow a dog owner to keep a dog that barks excessively in its loving home rather than to be forced to surrender it to a shelter.

Similar claims could be made for scratching behaviour undermining the attachment of owners to their cats; declawing could end the disruptive behaviour and allow for the continuance of the relation. However, evidence that declawing is a protective factor against relinquishment is weak. One study reported that considered in isolation, declawing made relinquishment less likely; but when all other related factors were taken into consideration, declawed cats were at an increased risk of relinquishment (Patronek, 2001), perhaps because declawing may trigger other unwanted behaviours such as biting or inappropriate urination (Jefferson, 2011). However, the evidence here remains contested.

In considering the indirect benefits argument, a number of further issues are raised. First, the acceptance of convenience procedures, especially in the United States, may result from an unrealistic expectation about what is involved in owning and caring for an animal. As discussed by Sandøe et al