Partial Digital Amputation (Onychectomy or Declawing) of the Domestic Felid - Position Statement

March 16, 2017

Background

1. Scratching is a normal feline behaviour. It is a means for cats to mark their territory both visually and with scent, and assists with nail conditioning and whole body stretching. Nails are used by cats to assist with balance, climbing, and self-defence.
2. Partial digital amputation (PDA) is the surgical removal of the third phalanx of each digit. Non-therapeutic PDA is generally performed for the convenience of the owner to eliminate the ability of a cat to cause damage from scratching. The surgery typically involves the digits of the front paws, although surgery on the digits of all four paws is sometimes undertaken.
3. Veterinarians strive to use their scientific knowledge to promote animal health and welfare and relieve animal suffering in keeping with the principles of veterinary medical ethics (1). With or without concrete scientific evidence, ethical consideration has to be given to the welfare of the animal. Veterinarians need to consider what advantages non-medically driven PDA’s offer to the feline. Viable alternatives to PDAs exist. Therefore from an ethical viewpoint, the CVMA views this surgery as unacceptable as it offers no advantage to the feline and the lack of scientific evidence leaves us unable to predict the likelihood of long-term behavioural and physical negative side effects.
4. The CVMA recognizes that appropriate medical therapy may necessitate surgery, including PDA (2). Medically necessary PDA surgery may include, but is not restricted to, biopsy of a nail or phalanx or surgery  to treat: neoplasia of nail bed or phalanges, severe or irreversible trauma, immune-mediated disease affecting nail bed, paronychia (inflammation or infection), onychodystrophy (abnormal formation), onychogryphosis (hypertrophy and abnormal curvature), onychomadesis (sloughing), onychomalacia (softening), onychomycosis (fungal infection), or onychoschizia (splitting) (3).
5. Surgical amputation of the third phalynx of the digit alters the expression of normal behaviours in cats, causes avoidable short-term acute pain, and has the potential to cause chronic pain and negative long-term orthopedic consequences (2,4-7).
6. As with any surgery, PDA can result in complications due to adverse reactions to anesthetics, hemorrhage, infection, and lack of effective perioperative pain management.
7. Since the third phalanx is removed by PDA, cats must thereafter bear their weight on the second phalanx. This fact has implicated PDA as a cause of lameness. It is recognized, however, that lameness is difficult to diagnose and detect (5). For this and other reasons the long term orthopedic effects of PDA are poorly understood.
8. A recent long-term study assessed cats six months after PDA (6,7). No significant differences were found between cats that had undergone bilateral forelimb onychectomy with successful outcomes and cats that had not. Specifically no differences were noted in peak vertical force and vertical impulse, the most commonly evaluated parameters in kinetic gait analysis, when measured at least 6 months after surgery. Since the original study only considered cats with successful surgical outcomes, the results likely have limited application and generalizability.
9. Both acute and chronic pain in felines can result in an increase in behaviours such as inappropriate elimination, excessive vocalization and increased aggression. The CVMA believes that current studies on long-term behavioural effects as a result of PDA are insufficient to draw firm conclusions about its role in causing chronic pain. The CVMA will therefore continue to review new studies as they are published (8,9).
10. It has been suggested that PDA be performed on cats in order to decrease the health risk to immunocompromised humans. The U.S. Centers for Disease Control and Prevention does not list PDA as a means of preventing disease in either healthy or immunocompromised individuals (10).
11. There are currently no peer-reviewed studies that identify a higher rate of relinquishment of cats with intact claws versus cats that have undergone PDA, including in countries in which PDAs have been banned. Partial digital amputation is not considered to be a justifiable alternative to relinquishment (11).
12. Tendonectomy is not an acceptable alternative to PDA because it causes similar pain post-surgery (8) and could lead to increased complications if the nails are not properly maintained.
13. Veterinarians should educate their clients about reasonable and effective alternatives to PDA including providing advice on the design and location of scratching posts and other suitable scratching materials and approaches aimed at preventing aggressive play behaviours.
14. Other strategies that offer alternatives to PDA include:

• feline pheromone sprays to redirect the cat to more desirable scratching materials;
• double-sided tape to deter cats from scratching the edges of furniture;
• regular nail trimming (recommended every two weeks);
• artificial nail covers;
• environmental enrichment and appropriate daily play to decrease feline aggression;
• avoidance of hand/foot play which can lead the cat to see these human parts as prey;
• the application of basic principles of reinforcement of desirable behaviour, including the use of catnip, treats, and verbal praise.

15. Partial digital amputation procedures are currently banned in several countries and/or regions including the United Kingdom (e.g., Ireland, England), Europe, and Australia.
16. In the current absence of a legislated ban on PDA surgery in Canadian jurisdictions, the CVMA, though opposed to elective and non-therapeutic PDA, supports the actions of provincial veterinary governing bodies that require that veterinarians, as a minimum, provide clients with information regarding PDA surgery, potential side-effects, and alternatives that is sufficient for owners to give informed consent (12).

17. Veterinarians have the right to refuse to perform non-therapeutic PDA surgery. If alternatives fail to alleviate undesirable scratching behaviours, veterinarians have the right and responsibility to use professional judgement for a humane and ethical outcome. 

References

1. CVMA Veterinarians Oath. 2004. Available from: https://www.canadianveterinarians.net/about/veterinary-oath Last accessed September 30, 2016.
2. Mills KE, von Keyserlingk MA, Niel L. A review of medically unnecessary surgeries in dogs and cats. J Am Vet Med Assoc 2016;248:162-171.
3. Verde M. 2005. Canine and Feline Nail Diseases. Proceedings of the NAVC. Available from: http://www.ivis.org/proceedings/navc/2005/SAE/110.pdf?LA=1 Last accessed August 2, 2016.
4. Robinson DA, Romans CW, Gordon-Evans WJ, et al. Evaluation of short-term limb function following unilateral carbon dioxide laser or scalpel onychectomy in cats. J Am Vet Med Assoc 2007;230:353–358.
5. Stamper C. Osteoarthritis in Cats: A More Common Disease Than You Might Expect. Available from: http://www.fda.gov/AnimalVeterinary/ResourcesforYou/AnimalHealthLiteracy/ucm382772.htm Last accessed March 30 2016.
6. Romans CW, Conzemius MG, Horstman CL, Gordon WJ, Evans RB. Use of pressure platform gait analysis in cats with and without bilateral ocychectomy. Am J Vet Res 2004;65:1276-1278.

7. Schnabl E, Bockstahler B. Systematic review of ground reaction force measurement in cats. Vet J 2015;206:83-90.
8. Hellyer P, Rodan I, Brunt J, Downing R, Hagedorn JE, Robertson SA. AAHA/AAFP pain management guidelines for dogs and cats. J Fel Med and Surg 207;9:466-480.
9. Cloutier S, Newberry RC, Cambridge AJ, Tobias KM. Behavioural signs of postoperative pain in cats following onychectomy or tenectomy surgery. Appl Anim Behav Sci 2005;92:325-335.
10. Panel on Opportunistic Infections in HIV-Infected Adults and Adolescents. Guidelines for the prevention and treatment of opportunistic infections in HIV-infected adults and adolescents: Recommendations from the Centers for Disease Control and Prevention, the National Institutes of Health, and the HIV Medicine Association of the Infectious Diseases Society of America. Available from: https://aidsinfo.nih.gov/contentfiles/lvguidelines/adult_oi.pdf Last accessed March 30 2016.
11. ASPCA Position Statement on Declawing Cats. Available from: http://www.aspca.org/about-us/aspca-policy-and-position-statements/position-statement-declawing-cats. Last accessed March 30, 2016.
12. Nova Scotia Veterinary Medical Association Information and Consent Form for clients who request cat declawing. Available from: http://celticcreatures.ca/wp-content/uploads/sites/281/2015/04/declaw.pdf.Last accessed March 30, 2016.

(Revised November 2016)