Prevalence of onychectomy in cats presented for veterinary care near Raleigh, NC and educational attitudes toward the procedure

Veterinary Anaesthesia and Analgesia, 2014, 41, 48 53 doi:10.1111/vaa.12077 RESEARCH PAPER Prevalence of onychectomy in cats presented for veterinary care near Raleigh, NC and educational attitudes toward the procedure Laura E Lockhart*, Alison A Motsinger-Reif, Wendy M Simpson & Lysa P Posner* *Department of Molecular and Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA Department of Statistics, Bioinformatics Research Center, North Carolina State University, Raleigh, NC, USA Morrisville Cat Hospital, Morrisville, NC, USA Correspondence: Lysa Posner, Department of Molecular and Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27607, USA. E-mail: lysa_posner@ncsu.edu Abstract Objective The current prevalence of onychectomy (declawing) in cats is unknown, and education regarding the procedure appears to vary greatly among veterinary schools. The purpose of this project was to determine the prevalence of onychectomized cats near Raleigh, NC and to document the frequency and style (laboratory or lecture) with which the procedure is taught in USA veterinary schools. Animals One thousand seven hundred ninety four cats ranging in age from 8 days to 21 years, of which 938 (52.3%) were female and 1719 (95.8%) were sterilized. Methods Data were collected over a 10-week period regarding cats seen for appointments in five veterinary facilities (two cat-only, two general, and one tertiary). Data collection included signalment and onychectomy status. During this time, 28 veterinary schools were polled regarding education of veterinary students in onychectomy. Results Three hundred and seventy four (20.8%) cats had undergone onychectomy. A significantly higher percentage of declawed cats were seen in the general practices compared with the other practice types (p < 0.030). Younger cats had a higher rate of onychectomy (p < 0.001). Twenty-six veterinary schools responded to the survey (93%). Fourteen (54%) of the responding schools did not include in their core curriculum a lecture or surgical laboratory providing instruction in the onychectomy procedure. Conclusions and clinical relevance Almost 21% of cats seen in veterinary hospitals near Raleigh, NC were declawed. Less than 50% of veterinary schools in the USA include a mandatory lecture or laboratory to teach the procedure. There appears to be a discrepancy between the popularity of the onychectomy procedure and the emphasis placed on relevant instruction in veterinary schools in the USA. Keywords cat, declaw, education, onychectomy, pain, sterilization. Introduction Onychectomy in cats is a controversial elective procedure that involves the removal of the third phalanx using a guillotine-type nail clipper, surgical blade, or laser (Shwartz 2001; Swiderski 2002). The onychectomy procedure is legal and performed throughout most of the United States, except in eight California cities, where the procedure has been 48

banned (Whitcomb 2010). The most common indication for performing onychectomy is unwanted scratching behavior causing personal injury or property damage (Patronek 2001; Shwartz 2001). Other indications for onychectomy include medical conditions of the patient, such as paronychia or nail bed neoplasms, and to prevent spread of zoonotic disease, as might occur in owners with immunodeficiency (Mison et al. 2002; Atwood-Harvey 2005). Onychectomy has both long- and short-term complications including pain, hemorrhage, soft tissue swelling, incisional dehiscence, infection, draining tracts, nerve trauma and lameness (Patronek 2001; Mison et al. 2002). It has also been suggested that onychectomy may cause stress in cats due to their inability to perform natural behaviors (Patronek 2001). Some veterinarians consider elective onychectomy unethical and refuse to perform the procedure (Patronek 2001). Alternative therapies may be employed to deal with unwanted scratching behavior, including environmental and behavioral manipulation, as well as other non-surgical techniques such as plastic nail coverings (Swiderski 2002). However, the authors are aware that many veterinarians performing onychectomy on a routine basis prefer to do so as an alternative to euthanasia, placing an indoor cat outdoors, or abandonment. Only a few surveys have been conducted to investigate the prevalence of onychectomy in cats, with the most recent published over a decade ago. A study conducted by the National Council for Pet Population Study and Policy in 2001 surveyed 3465 households in the USA and documented that approximately 24.4% of owned cats were onychectomized (declawed) (Patronek 2001). A local telephone survey conducted in Indiana in 1994 found that 45% of household cats had undergone onychectomy (Patronek et al. 1997). Other studies have attempted to predict the prevalence of onychectomy by comparing the rate of onychectomy procedures performed to the rate of neuters performed in hospitals. At one hospital in Colorado, an average of 5.3 onychectomies (22%) were performed for every 23.7 feline neuters (Wagner & Hellyer 2000). Not only is there a shortage of information regarding the prevalence of declawed cats in the USA, there is no compiled information regarding the instruction of veterinary students in the onychectomy procedure. Anecdotal information suggests that USA veterinary schools vary in the methods used to teach the onychectomy surgery and even whether the procedure is taught at all. Based on the previous surveys and anecdotal evidence, it is likely that many cats in the USA undergo onychectomy. This is a procedure that most veterinarians agree results in severe pain (Cambridge et al. 2000; Gaynor & Muir 2008). Force plate analysis of cats following onychectomy has demonstrated that cats have abnormal gaits for at least 12 days after surgery (Romans et al. 2005). Therefore, it is imperative that cats undergoing this procedure receive appropriate anesthesia and analgesia. The purpose of this study was to 1) determine the prevalence of onychectomy in cats scheduled for veterinary appointments at five hospitals located within 10 miles of Raleigh, NC; and 2) to determine the extent of instruction in the onychectomy procedure in USA veterinary schools. We hypothesized that, although still commonly performed in the USA, onychectomy has decreased in prevalence over time. Materials and methods Onychectomy survey Data were recorded for all cats examined at five veterinary hospitals within 10 miles of Raleigh, NC between May 16 and July 22, 2011. Of the five hospitals, two are cat-only hospitals, two are general small animal practice hospitals, and one is a tertiary facility (Appendix 1). Seven services within the tertiary facility cooperated with data collection: cardiology, emergency and triage, internal medicine, oncology and radiation therapy, ophthalmology, orthopedic surgery, and soft tissue surgery. Designated employees at each hospital were asked to record on a paper worksheet for all cats seen for appointments the name or patient number, gender, reproductive status, birth date, and onychectomy status (thoracic limbs, all limbs, or no onychectomy). Data were recorded only once for each cat at each hospital. Curriculum survey Twenty-eight veterinary schools across the USA were surveyed via email about their methods for teaching the onychectomy procedure to veterinary students. A surgery or community practice faculty member was contacted and asked to either answer the survey questions directly, or relay the survey questions to a faculty member with the appropriate knowledge to answer them. Questions included 2013 Association of Veterinary Anaesthetists and the American College of Veterinary Anesthesia and Analgesia, 41, 48 53 49

whether any lectures or laboratories about onychectomy were provided as part of the curriculum and whether either of these was optional or mandatory. An additional question requested information about the opportunity for students to participate in the onychectomy procedure during their clinical year(s). Statistical analysis Comparison of the proportion of declawed cats between practice types was tested with chi-square tests of association. Significant comparisons were followed up with post-hoc pairwise contrasts. The mean age of declawed and non-declawed cats was compared. Because the distribution of the age of cats was non-normal, difference in prevalence by age was compared with a Wilcoxon-Rank Sum test. For these analyses, p 0.05 was considered statistically significant. Analyses were performed in Stata v9 (www. stata.com). The p-values presented here are uncorrected for multiple testing (between hospital types), and it is discussed in the results if these conclusions would still be significant after a Bonferroni correction for the number of contrasts performed. practice 2 (Table 1) (p < 0.170). General practice 1 had a significantly higher proportion of declawed cats than General practice 2 (p < 0.001). There was a significant difference (p < 0.030) in the proportion of declawed cats between the three practice types, with the general practices having a higher proportion of onychectomized cats than the cat practices and the tertiary practice (Table 2), though this conclusion would not be statistically significant after multiple testing corrections. Twenty-six of the 28 veterinary schools that were surveyed regarding their instruction of the onychectomy procedure responded to the survey (Table 3). Four of the twenty-six schools (16%) did not perform onychectomy in their teaching hospitals; therefore, students had no opportunity to learn the procedure in their clinical years. Three of these schools (12% of all schools surveyed) did not offer instruction by optional or mandatory lectures or laboratories. Discussion Greater than 20% of cats presented for veterinary care in the surveyed practices near Raleigh, NC Results Data were collected from 1794 cats ranging in age from 8 days to 21 years (9 unknown), of which 938 (52.3%) were female and 1719 (95.8%) were sterilized. The age (mean SD) of non-declawed cats was 10.5 4.9 year (n = 1420) and of declawed cats was 8.9 5.7 year (n = 374). The mean age of declawed cats was younger than the mean age of cats not declawed (p < 0.001). There was no significant difference in the proportion of declawed cats between Cat practice 1 and Cat Table 2 The prevalence of onychectomy in cats presented during a 10-week period to five veterinary practices (categorized by practice type) near Raleigh, NC. Differing superscripts denote significant differences Practice type Total number of cats Onychectomized cats n (%) General practice 410 123 (30.0) a Cat-only practice 1170 211 (17.9) b Tertiary practice 214 40 (18.7) b Table 1 The prevalence, number (%), of onychectomy in cats presented during a 10-week period to five veterinary practices near Raleigh, NC Practice* Total number of cats Thoracic limb onychectomy n (%) All limb onychectomy n (%) Onychectomy n (%) General practice 1 276 88 (31.9) 10 (3.6) 98 (35.5) General practice 2 134 21 (15.7) 4 (3) 25 (18.7) Cat-only practice 1 699 118 (16.9) 16 (2.3) 134 (19.2) Cat-only practice 2 471 75 (15.9) 2 (0.42) 77 (16.3) Tertiary practice 214 35 (16.4) 5 (2.3) 40 (18.7) All practices combined 1794 337 (18.8) 37 (2) 374 (20.8) *See Appendix 1 for practice information. 50 2013 Association of Veterinary Anaesthetists and the American College of Veterinary Anesthesia and Analgesia, 41, 48 53

Table 3 Number of veterinary schools offering lectures and laboratories in the preclinical years to teach the onychectomy procedure (total number of responding schools: n = 26) Student participation Lecture Laboratory Mandatory 10 (38%) 4 (15%) Optional 2 (8%) 9 (35%) None 14 (54%) 13 (50%) were declawed. This rate is similar to that reported (24.4%) in a nationwide survey in 2001 (Patronek et al. 1997) and for the declaw to neuter ratio (22%) evaluated in a single Colorado practice (Wagner & Hellyer 2000). It is interesting and perhaps surprising that even with its controversial nature, the prevalence of onychectomy in cats apparently has not changed in the last decade. This study included a variety of types of practices and included a large sample size of cats. Thus the results are presumed to be representative of cats receiving health care within the Raleigh, NC region. However, this study did not include cats that were not presented for veterinary care and their impact on the percentage of onychectomy in all cats is unknown. It is likely that some indoor, declawed cats are not routinely presented for veterinary care either because they are not ill, or because their owners believe vaccinations are less warranted for indoor cats. Conversely, some outdoor cats with claws may not be routinely presented for veterinary care. Regardless of the exact percentage, the fact that more than one-fifth of cats seen for healthcare appointments in the region have undergone onychectomy is documentation that the surgery is routinely performed. This study also documented a higher rate of onychectomy in younger cats. Although it is possible that the procedure has become more common, our data does not support an overall increase in prevalence of cats that are declawed. Alternatively, younger cats might be presented more frequently either for vaccines, sterilization or medical problems. The increased prevalence of onychectomy in younger cats may also reflect the possibility that declawed cats are less likely to survive to older ages. It has been suggested that declawed cats are more likely to bite and eliminate outside of their litter box (Patronek 2001; Yeon et al. 2001). Such behavioral problems or other factors that increase with age, such as boredom and weight gain, may cause people to send a once indoor-only cat outdoors, making them more prone to fatal traumatic injuries and infectious diseases (Olsen & Allen 2001; Levy et al. 2006). Ongoing behavioral issues may also render it more likely for declawed cats to be euthanized. Furthermore, people who adopt older stray or shelter cats might be less likely to have them declawed since the risks and complications associated with the procedure increase with age (Franks et al. 2000). Finally, the geographic mobility of a community may contribute to differences in declaw prevalence. Raleigh, NC is a rapidly growing community and it is likely that many adult cats are being brought to the region from other places. Social and economic differences may contribute to the likelihood of being declawed. For example, the procedure is outlawed in other areas of the USA, including Southern California where presumably the prevalence of onychectomy is lower. The data collected on each cat regarding onychectomy status included only whether or not the cat was currently declawed, and no information was collected regarding where the procedure was performed. Because of this, the finding that General practice 1 had a significantly higher prevalence of onychectomy than General practice 2 did not necessarily relate to the number of procedures performed at each practice. This difference may exist because of a difference in clientele (i.e. income, housing) or a difference in practice philosophy regarding the onychectomy procedure. However, cats that had undergone onychectomy may have had the procedure done elsewhere prior to being seen as a patient at the clinic surveyed, making it difficult to interpret the significant difference between the two general practices. That the general practices had a significantly higher prevalence of cats that were onychectomized than the other two types of practices (cat-only and tertiary) could be an indication that general practices are more likely to recommend onychectomy rather than refer clients to alternative solutions for preventing scratching behavior. Alternatively, catonly practices may have the specific expertise and the time to consult on feline behavioral issues as compared to general practices. It could also be true that clients who bring their cats to cat-only and tertiary practices are seeking higher levels of catspecific care and are more willing to commit the time and patience that are required for alternative methods to onychectomy. 2013 Association of Veterinary Anaesthetists and the American College of Veterinary Anesthesia and Analgesia, 41, 48 53 51

Almost 93% of USA veterinary schools responded to our survey, and all geographic areas were represented. Of the veterinary schools that responded, more than half (54%) have no mandatory lectures or laboratories in their pre-clinical curriculum to teach the onychectomy procedure and 12% of the responding schools do not offer formal instruction or clinical opportunities to learn the procedure. A complicating factor in assessing when and how onychectomy might be taught is that some schools offer tracking to students to emphasize certain species or practice focus. The survey in this study did not differentiate how many of the responding schools offered tracking programs. It is therefore possible that in some schools with tracking programs, onychectomy exposure might be considered optional as opposed to mandatory but the overall rates of availability of exposure to the procedure would not change. It is also interesting to contemplate why there is a disconnect between the rate of onychectomy and the level of instruction at veterinary schools in the USA. Based on the results of this study, the percentage of cats seen in veterinary practices that have been declawed has changed little in the past decade. To the authors knowledge this is the first study to assess the level of instruction of this procedure in the veterinary curriculum nationwide, so it is not possible to assess if the level of instruction has changed. Nevertheless, ethical concerns and consideration of public, and perhaps student, opinions may have resulted in veterinary schools decreasing the instruction in onychectomy. What is also not known is whether that decrease in instruction will lower the rates of onychectomy in privately owned cats or whether veterinarians will learn the techniques elsewhere (e.g. colleagues, continuing education, textbooks). The lack of formal instruction in onychectomy potentially has far-reaching effects. The obvious concern would be the potential for poor surgical technique that could increase the prevalence of short and long term complications. In addition to surgical technique, there would also be concern for the lack of instruction of anesthetic and analgesic techniques appropriate for what most veterinarians consider a procedure that results in severe pain. Although this project was prospective, a number of potential and actual limitations should be considered. Data was collected from busy veterinary practices and services; so it is possible that data from some animals was not collected. However, since the omissions should have been random with respect to declawed and non-declawed cats, and with almost 2000 cats in this study, the effect on rate should be minimal. Similarly, data about education were collected from busy faculty members. It is possible that those faculty members who responded may not have known all the opportunity available for their students or mistakenly reported opportunities that were no longer offered at their college. Since 20.8% of cats seen in this study were declawed and that the percentage of onychectomy was higher in younger cats, it is clear that onychectomy surgeries are still being performed rather frequently. A discrepancy exists between how commonly cats are undergoing onychectomy and the amount of emphasis placed on its instruction in veterinary schools. References Atwood-Harvey D (2005) Death or declaw: dealing with moral ambiguity in a veterinary hospital. Soc Anim 13, 315 342. Cambridge AJ, Tobias KM, Newberry RC et al. (2000) Subjective and objective measurements of postoperative pain in cats. J Am Vet Med Assoc 217, 685 690. Franks JN, Boothe HW, Taylor L et al. (2000) Evaluation of transdermal fentanyl patches for analgesia in cats undergoing onychectomy. J Am Vet Med Assoc 217, 1013 1020. Gaynor JS, Muir WW III (2008) Handbook of Veterinary Pain Management-E-Book. Mosby, St Louis, USA. Levy JK, Scott HM, Lachtara JL et al. (2006) Seroprevalence of feline leukemia virus and feline immunodeficiency virus infection among cats in North America and risk factors for seropositivity. J Am Vet Med Assoc 228, 371 376. Mison MB, Bohart GH, Walshaw R et al. (2002) Use of carbon dioxide laser for onychectomy in cats. J Am Vet Med Assoc 221, 651 653. Olsen TF, Allen AL (2001) Causes of sudden and unexpected death in cats: a 10-year retrospective study. Can Vet J 42, 61 62. Patronek GJ (2001) Assessment of claims of short- and long-term complications associated with onychectomy in cats. J Am Vet Med Assoc 219, 932 937. Patronek GJ, Beck AM, Glickman LT (1997) Dynamics of dog and cat populations in a community. J Am Vet Med Assoc 210, 637 642. Romans CW, Gordon WJ, Robinson DA et al. (2005) Effect of postoperative analgesic protocol on limb function following onychectomy in cats. J Am Vet Med Assoc 227, 89 93. Shwartz S (2001) Onychectomy & Tendonectomy. NAVC Clinician s Brief March, 79 83. 52 2013 Association of Veterinary Anaesthetists and the American College of Veterinary Anesthesia and Analgesia, 41, 48 53

Swiderski J (2002) Onychectomy and its alternatives in the feline patient. Clin Tech Small Anim Pract 17, 158 161. Wagner AE, Hellyer PW (2000) Survey of anesthesia techniques and concerns in private veterinary practice. J Am Vet Med Assoc 217, 1652 1657. Whitcomb R (2010) California cities line up to enact cat declaw bans. DVM360: The DVM Newsmagazine January 1, 3. http://veterinarynews.dvm360.com/dvm/ article/articledetail.jsp?id=653155 Yeon SC, Flanders JA, Scarlett JM et al. (2001) Attitudes of owners regarding tendonectomy and onychectomy in cats. J Am Vet Med Assoc 218, 43 47. Received 6 November 2012; accepted 22 May 2013. Appendix 1 Veterinary hospitals participating in this study General Practice Bowman Animal Hospital and Cat Clinic, Raleigh, NC, USA. Chatham Animal Hospital, Cary, NC, USA. Cat-Only Practice Cozy Cat Veterinary Hospital, Raleigh, NC, USA. Morrisville Cat Hospital, Raleigh, NC, USA. Tertiary Practice North Carolina State University Veterinary Health Complex, Raleigh, NC, USA. 2013 Association of Veterinary Anaesthetists and the American College of Veterinary Anesthesia and Analgesia, 41, 48 53 53