Connection between early neutering and joint disorders in German Shepherd Dogs needs more research

I was pleased to see the JAVMA News story¹ concerning the study by Hart et al² on the effects of early neutering in German Shepherd Dogs. Although I don't doubt that there is an association between cranial cruciate ligament disease and early neutering, I do have concerns with these types of retrospective studies and the findings they produce. I have a number of patients that are sexually intact. Most of them are working dogs (eg, sled dogs, hunting dogs, search dogs, and police dogs) that come from kennels where athletic performance is paramount. Members of the same breed that were adopted from rescue organizations and were neutered early likely did not have such carefully selected parents. I spayed my own Labrador Retriever at 8 months of age almost 14 years ago and have not seen any hip or stifle joint problems. However, my dog's breeder is conscientious, and I imagine my dog's soundness is a result of excellent breeding and not simply a matter of being lucky enough to have avoided problems associated with neutering prior to 1 year of age.

I applaud Hart et al for pursuing their study for so many years and believe the data they have accumulated are invaluable. My concern, however, is that there may have been some degree of selection for better conformation among dogs that remained sexually intact, decreasing the risk of joint disorders in this group. It would be helpful to know the origin of the dogs in this study or to analyze subgroups of dogs based on early hip joint conformation. My guess is that delaying neutering will not undo poor conformation, nor will excellent conformation be undone by neutering prior to 1 year of age. It would be helpful to sort this out.

Margaret Eastman, dvm

Bay East Animal Hospital Green Bay, Wis

The recent JAVMA News story “Early neutering triples the risk of joint disorders in German Shepherd Dogs”¹ highlights a study funded by the American Kennel Club's Canine Health Foundation and the University of California's Center for Companion Animal Health that raises important questions about the relationship between age at the time of neutering and medical outcomes for German Shepherd Dogs.² However, we do not believe it is possible to adequately answer these questions with the data set, study design, and analytic approaches used in this study.

The referenced study² used the records database of the University of California-Davis Veterinary Medical Teaching Hospital, which functions not only as a primary care facility but also as a secondary and tertiary care center for referral cases. Thus, we believe the database was inadequate for measuring the incidence of medical conditions in a general population. In particular, the database likely included a large number of dogs referred because of an unusual condition or more severe manifestation and whose owners chose to travel to the facility. The frequency of referral over the 14.5-year study period likely varied depending on changes in specialty interests of the faculty members and availability of funding for treatment. In contrast, animals with conditions that are typically managed by primary care veterinarians are frequently underrepresented in the databases of veterinary teaching hospitals.³ For example, Hart et al² reported that mammary cancer was diagnosed in 4% of sexually intact females. However, it seems unlikely that this percentage captures the true incidence in the general population of German Shepherd Dogs because many dogs with mammary cancer are managed by primary care practitioners and never would have been referred.

In addition, associations identified in the study by Hart et al may not represent cause-and-effect relationships because the study could not account for the reasons that specific animals were neutered. Consider, for example, a puppy whose owners were advised to have the dog neutered at a young age because a littermate had an unusual gait or improper conformation. In this case, it was the propensity for joint problems that prompted the early neutering, and not the early neutering that caused joint problems. Similarly, increased age is a risk factor for cancer,^4,5 and it is therefore standard practice to adjust for the effect of age when assessing the causes of cancer.⁵ However, Hart et al did not report adjusting for confounding by age.

At end, we believe that the biased subject selection methods, incomplete measurement of disease frequency, and lack of consideration of noncausal explanations for identified associations make the results unreliable for assessing cause-and-effect relationships between age at the time of neutering and risk of disease.

C. Victor Spain, dvm, phd

Margaret Slater, dvm, phd

Stephanie Janeczko, dvm, ms

Lila Miller, dvm

Jed Rogers, dvm

American Society for the Prevention of Cruelty to Animals

New York, NY

Margaret V. Root Kustritz, dvm, phd

Assistant Dean of Education

College of Veterinary Medicine

University of Minnesota

Saint Paul, Minn

Philip A. Bushby, dvm, ms

Department of Clinical Sciences

College of Veterinary Medicine

Mississippi State University

Starkville, Miss

Defining success when it comes to diversity

A recent JAVMA News story¹ reporting on this year's Midwest Regional Iverson Bell Diversity meeting quoted Dr. Willie Reed, dean of the Purdue University College of Veterinary Medicine, as stating during his keynote address that, “The profession needs to reflect the population. Our profession will become irrelevant if we don't change with the world. Our country is diverse—we should be as well.”

I personally believe that there should never be any obstructions to any individual who meets the criteria for acceptance into veterinary college, other than those presented by the competitive admissions process (despite the recent increase in the number of veterinary colleges in the United States and the growth in class size among existing colleges, the number of applicants still exceeds the number of first-year seats).

However, many factors dictate whether any particular individual would be more or less likely to pursue a veterinary education. In particular, it seems unlikely that individuals who lack extensive interactions with animals during their formative years would pursue a veterinary career. Other major influences on the career path young people choose include geographic location (urban vs suburban vs rural) and ethnic cultural biases.

There are numerous professions that have a membership that does not reflect the general population yet remain relevant to society. Examples include professional athletics, farming and ranching, and the airline pilot profession. Before attempting to increase diversity in these professions, or in the veterinary profession, we need to have a better understanding of the factors that lead to these distributions. We also, I believe, need to better understand how success is defined when it comes to diversity. Obviously, no one believes that 0.33% of the veterinary profession should be Ukrainian-Americans simply because Ukrainian-Americans represent 0.33% of the overall US population. It is important, therefore, that as a profession we clarify our expectations and define success in concrete terms. We must ensure there are no obstacles internal to our profession that might deny bright, caring, hardworking students who are passionate about animal health a fair opportunity to attend veterinary college. However, amending factors external to our profession would seem to be beyond our collective scope.

Robert B. Cherenson, dvm Turlock, Calif

Exploring the need to discuss onychectomy in depth with clients

I was happy to see the subject of feline onychectomy brought up for discussion in the JAVMA, specifically through publication of the results of a survey of Veterinary Information Network members regarding their attitudes toward this procedure.¹ Given my own feelings on the subject, I was glad to see that 24.0% of respondents indicated that they do not perform onychectomy.

According to the report, 74.6% of respondents who performed onychectomy indicated that they recommended nonsurgical alternatives before performing the procedure. However, data were not given regarding how much information was provided when discussing nonsurgical alternatives or, more importantly, whether these discussions related only to alternative procedures or also included specific details of the onychectomy procedure and its potential long-term implications.

Over the past several years, I have talked to owners of dozens of declawed cats. Time and time again, I learned that none of them were aware that declawing represented amputation of the distal phalanges. I would challenge veterinarians who perform this procedure, therefore, to alter their paperwork so that it no longer refers to “declawing” but rather to “amputation of the last phalanx (bone) of the digits.” Owners who sign consent forms should know what they are paying for.

Jennifer Doll, dvm

Solon, Iowa

The authors respond:

Thank you for your comments regarding our survey of Veterinary Information Network members regarding practices and perceptions related to onychectomy. We were pleased to discover that 74.6% of respondents recommended alternatives to declawing, which included scratching devices, nail-trimming demonstrations, nail covers, deterrence materials, synthetic appeasing feline facial pheromone spray, behavior modification, and prescription medication. We were also heartened by results indicating that respondents who did perform onychectomy did so fairly infrequently, with 64.1% reporting that they performed the procedure less than monthly and 28.3% reporting that they performed it less than weekly but more than monthly.

In the survey, we only asked what nonsurgical alternatives were recommended and did not ask how much emphasis was placed on any of these alternatives. Similarly, we did not ask what terminology the veterinarian or staff members used to describe the onychectomy procedure. Dr. Doll raises an interesting question of whether owners would be less likely to declaw their cats if veterinarians called the procedure “amputation of the last phalanx (bone) of the digits” instead of the more commonly used term of “declawing.” Certainly, the language we use to describe a procedure has an impact on how we view it (eg, major versus minor procedure, mutilation versus cosmetic surgery, lifesaving versus life-altering procedure). The authors are interested in continuing this line of research to determine what role terminology plays in the owner decision-making process. In the authors’ opinion, veterinarians have a duty to advocate in the best interests of their animal patients and to accurately inform owners of the nature of the procedures they are requesting, including both the pros and cons. Dr. Doll's challenge to the profession is a timely reminder for all veterinarians to consider how we view and talk about onychectomy and the impact this can make on owners’ decisions.

Peter W. Hellyer, dvm

Rebecca Ruch-Gallie, dvm

Lori R. Kogan, phd

Department of Clinical Sciences

College of Veterinary Medicine and Biomedical Sciences

Colorado State University

Fort Collins, Colo

Regina Schoenfeld-Tacher, PhD Department of Molecular Biomedical Sciences

North Carolina State University

Raleigh, NC

More support for nixing preveterinary requirements

I fully support the recent call to reduce preveterinary requirements as one way to help reduce the educational debt of veterinary students.^1,2 One of the best qualified, most professional veterinarians with whom I ever worked graduated from veterinary school at age 21. During World War II, preveterinary requirements were waived, and he attended classes year-round.

Eliminating all unnecessary preveterinary requirements would seem to be one of the easiest ways to reduce the debt of newly graduated veterinarians. My preveterinary education consisted of two academic years and one summer semester of classes. However, the only reason summer school was required was because during my first year, I was in the college of engineering and took classes such as drawing and calculus that were not preveterinary requirements.

Help the veterinary students. Scrub all the unnecessary preveterinary requirements.

William Kerr, dvm, mph, ms

Corpus Christi, Tex

Perspective on the UW Madison tuition increase

The August 15, 2016, issue of JAVMA contained a letter¹ from a recent University of Wisconsin School of Veterinary Medicine (UW SVM) graduate citing concerns about rising tuition and increasing educational debt for veterinary medical students. We at the UW SVM understand and share her concerns but believe that additional context is needed.

In the 15 years prior to the recent tuition increase at the UW SVM, there had been no increases to speak of, despite declining state support for public higher education. Given the historical decline in state support, maintaining educational excellence has been difficult, particularly as the costs associated with higher education have continued to rise.

At the time the proposal was made to increase tuition at the UW SVM, our tuition costs were the lowest for nonresident students and near the lowest for resident students among colleges of veterinary medicine in the United States. In fact, it was cheaper for students from one of our neighboring states to attend the UW SVM than it was for them to attend the college in their home state. Although tuition is increasing, the increase is being implemented gradually over a 4-year period, and a large portion of the new revenue will flow to scholarship support, which will double from $1 million to $2 million per year. The new revenue will also fund several educational initiatives that strengthen our veterinary curriculum, such as 1-week selective courses and blended learning modules that expose students to hands-on experiences and topics beyond what is traditionally taught or encountered in the clinic. These enhancements provide our students with a wider range of knowledge and improve their performance in the core competencies of veterinary medicine.

When the increase is fully realized, our tuition costs will be near the mean for our peer institutions. At the same time, we have long maintained a top 5 ranking among the nation's schools of veterinary medicine and are recognized worldwide for providing a veterinary medical education of the highest quality. A high-quality education comes with requisite costs for the exceptional faculty and state-of-the-art equipment needed to prepare students for entry into the veterinary medical profession. The desire to provide an excellent education, not the pursuit of prestige, always drives our decision-making, including the decision to raise tuition.

We care very much about the challenges facing today's students, and we do not take tuition increases lightly, as evidenced by the large gap between our last 2. And, because we recognize and sympathize with student concerns about rising costs and increasing debt, we are working to mitigate student debt by increasing scholarship opportunities through fundraising. We also offer professional development workshops designed to help our students make better informed decisions about their finances. And, we will continue to make the case to our state government that the substantial societal contributions of our school and graduates warrant greater investment of public resources.

Mark D. Markel, dvm, phd

Dean

School of Veterinary Medicine

University of Wisconsin

Madison, Wis

Evolving terminology for injection-site sarcomas in cats

It has been nearly 25 years since Hendrick and Goldschmidt¹ first raised concerns about the possibility of injection-site sarcomas in cats. In their letter, they noted an unusual increase in the number of fibrosarcomas in cats that seemed to correspond to a 1987 Pennsylvania state law requiring rabies vaccination of cats. Since that initial letter, numerous epidemiological and pathological studies have been conducted, the results of which support the idea that chronic irritation associated with vaccine administration, especially administration of killed adjuvanted vaccines, and a genetic predisposition are the most important factors associated with malignant transformation.^2–5 This condition was first named feline vaccine-associated sarcoma (FVAS), but in more recent years, the term feline injection-site sarcoma (FISS) has been used.

Recently, we performed a literature survey in PubMed of articles published between 1991 and 2015 with these 2 conditions as search terms. We identified 106 papers discussing the targeted disease and found that the transition from FVAS to FISS happened between 2003 and 2007. Within this time frame, we located some key papers that may have contributed to the change in terms and found that the main argument was that various types of injections other than vaccination may also be associated with sarcoma formation.

Nevertheless, it appeared that the overwhelming majority of reported cases of FISS were associated with vaccine administration, with only a handful of cases attributed to other injectable agents. In addition, many case reports of sarcoma formation associated with other injectable agents did not appear to rule out prior vaccination at the same site.⁴ A 2003 multicenter case-control study⁶ did find that methyl prednisolone acetate and penicillin had been used more frequently in cats with sarcomas than in control cats, but even in this study, it appeared that the tumorigenic potential of these nonvaccine injectable agents was limited.

The change in terminology from FVAS to FISS may, we believe, have unconsciously led to the perception that the causative agent for most injection-site sarcomas is elusive when, in fact, vaccination was most likely the underlying cause of sarcoma formation. After 25 years, some vaccines are still leading to FVAS in numerous cats around the world.⁷ As the Vaccine-Associated Feline Sarcoma Task Force concluded in 2001,⁸ although we must continue to vaccinate cats against key infectious diseases, we must also continue to evaluate the potential advantages and limitations of new vaccines, including those with and without adjuvants.

Jason Lih-Seng Yeh, dvm, phd

Veterinary Teaching Hospital

National Taiwan University

Taipei, Taiwan

Tzann-Huey Chou, dvm, ms

Song-Yow Hou, dvm, ms

Asia-Pacific Animal Surgical Center

Taipei, Taiwan