Onychectomy, popularly known as declawing, is an operation to remove an animal's claws surgically by means of the amputation of all or part of the distal phalanges, or end bones, of the animal's toes. Because the claw develops from germinal tissue within the third phalanx, amputation of the bone is necessary to fully remove the claw. The terms "onychectomy" (origin: Greek ὄνυξ onycho, nail + ἐκτομή ektome, excision) and "declawing" imply mere claw removal, but a more appropriate description would be phalangectomy, excision of toe bone.
The amputation of the distal phalanx is indicated in case of chronic inflammatory processes, tumours, persistent and severe infections and gangrene that are limited to the distal phalanx. The procedure is usually limited to the affected claw, leaving the healthy claws (if any) intact.
In North America, declawing is commonly performed on cats to prevent damage to household possessions by scratching and to prevent scratching of people. The surgery involves amputating the distal phalanges of all toes on the front paws, and sometimes the rear paws as well. Although no precise figures are available, peer-reviewed veterinary journal articles estimate that approximately 25% of domestic cats in North America have been declawed. Some privately owned apartment buildings in the U.S. ban cats unless they have been declawed. This is not the case in publicly subsidized housing, however, because in 2007 the U.S. Congress enacted legislation that forbids public housing authorities from having such rules. Laws have been passed in California (2012) and Rhode Island (2013) that ban landlords from requiring the declawing cats as a condition of occupancy.
Some North American veterinarians hold the position that people with compromised immune systems, due to conditions such as AIDS, should have their cats declawed to prevent health risks to themselves. However, the U.S. Centers for Disease Control advises against declawing, even in the case of FIV, as "cats need their claws for a number of activities." Instead, the CDC recommends that those with HIV should avoid situations where they might get scratched. Similarly, the National Institutes of Health (NIH) suggests avoiding rough play. As a precautionary measure, Familydoctor.org  advises people should avoiding provoking cats into scratching them.
Despite the prevalence of elective onychectomy in North America, no standard practices exist regarding the surgical techniques or surgical tools used, the administration of post-operative analgesics or other follow-up care, or the optimal age or other attributes of cats undergoing the procedure. There are three surgical methods: scalpel blade, guillotine trimmers, and laser.
Onychectomy is an orthopedic surgery involving 1 (or more) separate phalangeal amputations, which requires general anesthesia and multi-modal pain management before, during, and after surgery.
In a survey of 276 cat owners, 34% reported post-surgical discomfort in their cats while 78% reported primarily tenderness. Recovery time took from three days to two weeks. Increased biting strength or frequency was reported in 4% of cats, but overall, 96% of owners were satisfied with the surgery. Some other studies found lameness after onychectomy lasting >3 days, >1 week, 8 days, > 12 days, 180 days, and 96 months.
At one veterinary teaching hospital, between 50 and 80% of cats had one or more medical complications post-surgery; 19.8% developed complications after release. Other studies have reported medical post-op complication rates as 24% (Jankowski 1998), 53% (Martinez 1993), 1.4% (Pollari 1996), 82.5% for blade and 51.5% for shear technique (Tobias 1994), and 80% (Yeon 2001). Reported medical complications include: pain, hemorrhage, laceration of paw pads, swelling, reluctance to bear weight on affected limb, neuropraxia (transient motor paralysis), radial nerve damage, lameness, infection, abscess, tissue necrosis, wound dehiscence, incomplete healing, protrusion of 2nd (middle) phalanx, claw regrowth, scurs (growth of deformed claw segments), retention of flexor process of third phalanx, chronic draining tracts, self-mutilation, dermatitis, lethargy, palmigrade stance (walking on wrists), chronic intermittent lameness, chronic pain syndrome, flexor tendon contracture, and cystitis (stress-associated bladder inflammation). Claw regrowth has been seen by veterinarians anywhere from weeks up to 15 years after onychectomy.(Veterinary Information Network).
In post-operation follow ups Yeon, et al. (2001) found six of thirty-nine cats (15%~) were house soiling and seven (18%) had increased biting frequency or intensity. The authors concluded based on this and previous studies that "behavioral problems following onychectomy were not pronounced". Follow-ups in this study were conducted an average of eleven and a half months after surgery.
Behavior problems are a primary cause of cats being relinquished to shelters. Proponents of declawing argue that declawing reduces undesired behaviors (scratching) and thus reduces the likelihood of relinquishment. Opponents of declawing argue the surgery itself creates more behavioral problems leading to relinquishment of cats. A study by Patronek et al. (1996) found in a univariate analysis that declawed cats were only 63% as likely to be relinquished as non-declawed cats. A multivariate analysis conducted in the same study shows odds of being relinquished to a shelter were 89% higher for declawed cats. The authors concluded that the conflicting results of the two analysis made it difficult to interpret the effects of declawing. In a shelter setting, more declawed cats were reported by their owners to have problems with inappropriate elimination (house soiling). However, this study ultimately found no association between the declaw status of cats and their aggression towards humans or frequency of inappropriate elimination (house soiling).
In another study, 16% of declawed cats developed behavior problems (12% biting), and more declawed (55%) than clawed (45%) cats were referred to a vet teaching hospital for behavior problems. This was the second-longest follow-up period (2 years) ever examined.
Patronek, Glickman and Beck (1996) found no association between the declaw status of cats and the frequency of inappropriate elimination (house soiling).
In another study of 275 cats, 11 cats (4%) developed or had worse behavior problems post-declawing; 5 clients (less than 1%) reported that their cats had developed litterbox and biting problems.
Chronic pain syndrome of onychectomy has been described by a pain management specialist as leading to unwanted behaviors, including increased aggression.
A prospective study comparing declawing with tendonectomy noted many medical as well as behavior complications.
An internet survey found that declawed cats were more likely to jump on tables and counters and house-soiled more than non-declawed cats (25% vs. 15%).
However, the current (2009) American Veterinary Medical Association (AVMA) policy statement on declawing states: "There is no scientific evidence that declawing leads to behavioral abnormalities when the behavior of declawed cats is compared with that of cats in control groups."
Laws and policies governing onychectomy vary around the world. For example, many European countries prohibit or significantly restrict the practice, as do Australia, New Zealand, Japan, and Turkey. It is banned in at least 22 countries. The list below gives an overview of the situation in different parts of the world.
In Australia, declawing has never been common, and for all practical purpose, does not exist. Nationwide legislation was recently enacted that prohibits the declawing of cats except for medical need of the cat. The Australian Veterinary Association's policy states: "Surgical alteration to the natural state of an animal is acceptable only if it is necessary for the health and welfare of the animal concerned. Performance of any surgical procedure for other than legitimate medical reasons is unacceptable."
In Israel, the Knesset Education Committee voted unanimously to send a bill banning the declawing of cats not for medical reasons. The bill has passed second and third readings on November 28, 2011, effectively making declawing a criminal offense with penalty of 1 year in prison or a fine of 75,000 Shekels.
In many European countries the practice is forbidden either under the terms of the European Convention for the Protection of Pet Animals or under Local Animal Abuse Laws, unless it is for "veterinary medical reasons or for the benefit of any particular animal." Some European countries go further, such as Finland, Sweden,  Estonia, the Netherlands, Germany and Switzerland, where declawing cats for non-medical reasons is always illegal under their laws against cruelty to animals.
In Austria, the Federal Act on the Protection of Animals, in Section 7, states, surgical procedures "carried out for other than therapeutic or diagnostic purposes...are prohibited, in particular...declawing."
In the United Kingdom, declawing was outlawed by the Animal Welfare Act 2006, which explicitly prohibited "interference with the sensitive tissues or bone structure of the animal, otherwise than for the purposes of its medical treatment." Even before the 2006 Act, however, declawing was extremely uncommon, to the extent that most people had never seen a declawed cat. The procedure was considered cruel by almost all British vets, who refused to perform it except on medical grounds. The Guide to Professional Conduct of the Royal College of Veterinary Surgeons stated that declawing was "only acceptable where, in the opinion of the veterinary surgeon, injury to the animal is likely to occur during normal activity. It is not acceptable if carried out for the convenience of the owner ... the removal of claws, particularly those which are weight bearing, to preclude damage to furnishings is not acceptable."
Declawing was outlawed in West Hollywood, California, in 2003, the first such ban in the US. The ordinance was authored by West Hollywood Councilmember John Duran and sponsored by The Paw Project, a non-profit organization started by Dr. Jennifer Conrad based in Santa Monica, CA. The California Veterinary Medical Association challenged the law in court. The CVMA maintained that West Hollywood had overstepped its municipal authority by enacting an ordinance that infringed on licensed professionals’ state-granted rights. It did not directly address declawing as an animal welfare issue. The CVMA initially prevailed in Superior Court, but in June 2007, the California Court of Appeal overturned the lower court ruling, thus reinstating the law banning declawing in West Hollywood.
In 2004, California became the first state in the USA to enact a statewide ban on the declawing of wild and exotic cats. The bill was introduced by California Assemblymember Paul Koretz and sponsored by the Paw Project. In 2006, the United States Department of Agriculture enacted a ban on declawing of all wild and exotic animals held by USDA-licensed owners.
In 2009, the California state legislature approved a measure, sponsored by the California Veterinary Medical Association (CVMA), intended to stop other cities from passing bans similar to West Hollywood's. By including in the bill all professions licensed by the state Department of Consumer Affairs, the CVMA got the bill pushed through, and it was signed by the Governor in July, 2009. However, the bill's effective date, January 1, 2010, provided enough time so that seven more California cities passed local bans against the declawing of domestic cats: Los Angeles, San Francisco, Burbank, Santa Monica, Berkeley, Beverly Hills, and Culver City.
In 2012, a California bill, authored by Senator Fran Pavley and sponsored by the Paw Project, was signed into law that prohibits landlords from requiring declawing and devocalization of animals as a condition of tenancy. In 2013, the state of Rhode Island enacted a law, similar to the California law, prohibiting landlords from requiring declawing as a condition of occupancy.
Declawing is widely practiced but ethically controversial within the American veterinary community. Some American and Canadian veterinarians endorse the procedure, while some have criticized and refused to perform it. Two animal protection organizations in the US, the Humane Society of the United States and the American Society for the Prevention of Cruelty to Animals, discourage the procedure. The Humane Society of the United States has supported legislation banning or restricting declawing. Opposition to attempts to ban or restrict declawing has come from veterinary trade organizations, such as the California Veterinary Medical Association. On the other hand, the American Veterinary Medical Association states that declawing "should be considered only after attempts have been made to prevent the cat from using its claws destructively or when its clawing presents a zoonotic risk for its owner(s)." Surveys suggest that 95% of declaw surgeries are done to protect furniture.
Tendonectomy involves cutting the deep digital flexor tendon of each claw, resulting in the cat being unable to move its distal phalanges. Without the ability to expose its claws, the cat is unable to wear down or groom its claws. For this reason, the cat subsequently requires regular nail clippings to prevent its claws from growing into its paw pads. A 1998 study published in the Journal of the American Veterinary Medical Association comparing cats undergoing onychectomy to cats undergoing tendonectomy found that, although the cats undergoing tendonectomy appeared to suffer less pain immediately post-operatively, there was no significant difference in postoperative lameness, bleeding, or infection between the two groups. A 2005 study found no evidence that tendonectomy is less painful than onychectomy. The American Veterinary Medical Association and the Canadian Veterinary Medical Association explicitly do not recommend this surgery as an alternative to declawing.
According to board-certified veterinary behaviorist Dr. Gary Landsberg, "For most cats, appropriate client advice and a little effort is all that is needed to prevent scratching problems.” However, many veterinary practitioners are unwilling or unable to offer solutions to behavioral problems such as scratching, other than declawing.
An effective non-surgical alternative to declawing is the application of vinyl nail caps (marketed in the US under brand names such as Soft Paws, available through veterinarians, and Soft Claws, sold through pet stores and online) that are affixed to the claws with nontoxic glue, requiring periodic replacement when the cat sheds its claw sheaths (usually every four to six weeks, depending on the cat's scratching habits).
Other alternatives include regular nail trimming; directing scratching behavior to inexpensive cardboard scratchers or scratching posts, or emery scratching pads that dull the claws; rotary sanding devices (Dremel, Pedi-Paws); covering furniture or using double-sided sticky tape or sheets such as Sticky Paws; remote aversive devices such as Scat Mats; or acceptance of cats' scratching behavior.