Alternative to declawing is just more of the same

I am shocked that JAVMA would print the letter from Dr. Kerry Yoon describing his alternative approach to declawing.¹ In performing this procedure, Dr. Yoon uses a nail trimmer and purposely leaves a fragment of the distal phalanx in place. Thus, the only real difference between his method and the one first described in 1952² is that he uses an electrocautery unit to destroy any germinal cells that might remain, which he claims prevents claw regrowth. However, because germinal cells are not visible to the naked eye, there is no way to tell whether the goal of destroying these cells is accomplished. Notably, a 2014 study³ found that claw regrowth was more common with the use of a guillotine (nail clipper) technique for onychectomy than with the use of a scalpel or laser technique, although the guillotine technique in that study did not include electrocauterization of the germinal cells.

Even if claw regrowth does not occur, leaving a fragment of the distal phalanx in place seems likely to cause pain, lameness, and other complications. In a 2016 study, Gerard et al⁴ concluded that their results “supported the hypothesis that onychectomy is associated with an increase in house soiling behavior of cats.”

Similarly, a retrospective cohort study⁵ involving 137 declawed and 137 nondeclawed cats found radiographic evidence of retained distal phalanx fragments in 63% (86/137) of the declawed cats, and declawed cats had higher odds of back pain, undesirable elimination habits, and aggression if they had retained distal phalanx fragments than if they did not. In addition, declawed cats had higher odds of biting and undesirable elimination habits than did nondeclawed control cats.

Dr. Yoon reports in his letter that postoperative complications have been rare following use of his technique. However, “absence of evidence is not evidence of absence,” as the saying goes, and it is not clear whether complications would have been reported by the cats' owners or even identified. For example, bilateral lameness may not be recognized by clients, and cats, because of their known stoicism, may be in pain without showing noticeable signs.

I do not believe that JAVMA should have published a description of this technique without any scientific study of its short- and long-term consequences. Dr. Yoon boasts that his technique is painless, but that claim and the claim that the procedure does not affect gait can, I believe, be dismissed out of hand.

The AVMA has condemned the declawing of captive exotic and wild indigenous cats because of concerns that the pain and suffering associated with declawing may be exacerbated in these populations⁶ and has also stated that “pain management is necessary (not elective) and required” for declawing of domestic cats,⁷ implying that the procedure causes pain and suffering in domestic cats also. The JAVMA editors should be ashamed to publish a letter that will likely result in even more cats suffering.

Jean Hofve, dvm

Denver, Colo

Report on alternative declawing method lacks detail

In response to Dr. Kerry Yoon's recent letter¹ describing his alternative method for declawing domestic cats, I have several questions and concerns.

First, Dr. Yoon suggests that his method preserves the connection of the flexor tendon (ie, the tendon of the deep digital flexor muscle) to the distal phalanx, “allowing the cat to maintain a normal stance.” However, there is no mention of integrity of the extensor tendon (ie, the tendon of the common digital extensor muscle). Maintaining the flexor tendon with no counteracting extensor tendon can be detrimental to the function of the digit and, in my experience, can lead to contracture of the flexor tendon later in life.

Second, the description of the postoperative care indicates that cats are “discharged the same day without any evidence of limping.” This needs clarification, as it suggests that analgesia is not routinely provided and that a lack of lameness is being used as the marker for a lack of pain. This procedure should never be performed without adequate postoperative analgesia. There have been many advances in identifying pain in cats over the past 5 years that involve evaluating them for more than lameness.²

Third, it is uncertain whether the method described would end all horn-generating epidermal activity. I have performed approximately 100 declaw revision procedures in the past 4 years to remove small and large remnants of the distal phalanx. Most fragments that still had active horn-generating epidermis also had abnormal tissue below the skin that was not externally visible. Further, the tissues that form the many components of the nail in cats originate from several locations, and I am skeptical that blindly cauterizing the phalanx is an effective method for preventing subsequent horn-generating activity. The external coronary horn originates from dermis that lines the internal surface of the ossified unguicular hood,³ which is located close to the extensor process of the distal phalanx, and would be difficult, if not impossible in my opinion, to reach with electrocautery alone. By contrast, the sole horn originates from dermis on the palmar aspect of the unguicular process.³ Other nail components originate from separate sites.

Finally, as with other partial amputation methods, there appears to have been little consideration of the potential for disruption of the growth plate of the distal phalanx. To my knowledge, there is no published research about the effects of distal phalangeal growth plate disruption in cats, but this theoretically has the potential to result in abnormal bone growth or a lack of bone growth.

I do not support the declawing of cats, even with this method. The reported results are anecdotal, with no verifiable data, and demonstrate the veterinary field's need for further research into the pathological consequences of declawing cats, no matter the method.

Nicole K. Martell-Moran, dvm, mph

Feline Medical Center Houston, Tex

Lameness in a 3-year-old backyard chicken

I read the recent What Is Your Diagnosis? article¹ describing a 3-year-old domestic hen with non-weight-bearing lameness and paresis of the left pelvic limb with interest. I applaud the effort, but was disappointed in several aspects of the report.

The need for a good relationship between knowledgeable poultry veterinarians and backyard flock owners is well presented in the article. Curiously, the differential diagnosis for the case did not mention lymphoid leukosis. Although Marek disease was a reasonable consideration, lymphoid leukosis would have been, I believe, a more relevant consideration in a 3-year-old chicken my current level of knowledge but should have been discussed by the authors. Also, reovirus infection, abnormal ovulation, mycoplasmal or bacterial infection, and trauma (which can occur without obvious damage to the external aspect) were valid considerations on initial observation. Clinicopathologic testing without a vaccination or health history, although useful, would not necessarily contribute to an accurate diagnosis.

Veterinary medicine, including poultry veterinary medicine—which I practiced for > 40 years—is largely isolated from small backyard flocks. State, federal, and university personnel and a few private practitioners do as well as can be expected, but the knowledge gap is still substantial. This void has widened even more with the growing popularity of backyard chickens and should be viewed with great concern, given the potential effects of this practice on the health of humans, poultry, and other animals.

I was also disappointed that the article did not include any comments about discussions between the attending veterinarians and the bird owner regarding the diagnostic process (including costs), the eventual euthanasia of the patient, or recommendations on general poultry health and husbandry practices.

For both humans and animals, a single medical visit during a time of crisis can be important. Of equal importance is building the knowledge, history, trust, and confidence required for a long-term, problem-solving veterinarian-client-patient relationship, and I did not read that activity in the article. The commercial poultry industries in the United States and around the world have succeeded, in part, by developing such relationships. Educating today's students on how they may establish these critical relationships by performing interesting, cost-effective, critical work, while also generating a successful living, is important to backyard flock owners, commercial poultry industries, society as a whole, and the veterinary profession.

Spangler Klopp, dvm

Lewes, Del

The authors respond:

The authors appreciate Dr. Klopp's interest, comments, and service to veterinary medicine. In response to Dr. Klopp's comments, we point out that the article was structured according to the “What Is Your Diagnosis” guidelines, which focus on the practice and application of diagnostic imaging. As such, detailed descriptions of client communications and clinicopathologic testing prior to imaging were truncated. Given these constraints and the 3-page limit, some of the points Dr. Klopp raises were beyond the scope of this article type. However, we would like to address a few of Dr. Klopp's points, keeping in mind the framework and intent of the article.

The article's purpose was to demonstrate how, in avian patients, radiography and ultrasonography can guide diagnosis and management. Dr. Klopp's clinical differential diagnoses for lateralizing paraparesis or paralysis (eg, mycoplasmal or bacterial infection and abnormal ovulation) are excellent and could indeed cause caudodorsal coelomic changes. However, these differential diagnoses were ruled out because they were not consistent with the imaging findings. Further, there was no history of trauma in this patient and no evidence of trauma on physical examination, and the patient had a radiographically and ultrasonographically visible and digitally palpable mass in the region of the kidney coupled with severe unilateral pelvic limb muscle atrophy and paresis. Given the sciatic nerve anatomy of birds, this constellation of findings is most consistent with a neoplastic mass involving the kidney and causing neuropathy. On the basis of the imaging features, a primary renal neoplasm was considered the most likely diagnosis, although an ovarian neoplasm could not be excluded.

At this stage, an exhaustive list of neoplastic types was not considered because the imaging findings did not allow further discrimination without tissue sampling. Carcinoma was considered most likely, as the chicken had a solitary lesion and carcinoma is a common renal neoplasm in birds. Histologic evaluation and CD3 labeling confirmed the T-cell phenotype of lymphoma, indicative of Marek disease. Lymphoid leukosis causes B-cell lymphoma.

As Dr. Klopp states, having a complete vaccination and health history would have been useful, but these are not always available to referral institutions. The authors are largely veterinarians working in support services (radiology and pathology) and would echo that having a complete clinical history is vital to obtaining an accurate diagnosis. Although the final diagnosis required histologic examination in this case, imaging facilitated rapid diagnosis of a renal mass, and consideration of reasonable differential diagnoses and prognosis on the basis of that finding allowed the owner to make an informed decision for the pet. Further history may have been useful, but in this case, the imaging obviated the need for additional testing, ultimately reducing costs for the owner. All costs for diagnostic testing, treatment, and euthanasia of the patient were discussed thoroughly with the owner throughout the process. As Dr. Klopp mentions, decisions can be difficult for owners in times of crisis; working in a referral hospital, we must be even more careful in navigating these discussions, as we may not always have a lengthy veterinary-client-patient relationship. In these instances, effective communication with the owner and referring veterinarian and having a complete and pertinent clinical history available are all the more vital.

Eli B. Cohen, dvm

Department of Molecular Biomedical Sciences

Heather R. Shive, dvm, phd

Luke B. Borst, dvm, phd

Department of Population Health and Pathobiology

Steven M. Bessauer Almeida, bs

College of Veterinary Medicine North Carolina State University Raleigh, NC