Age at gonadectomy, sex, and breed size affect risk of canine overweight and obese outcomes: a retrospective cohort study using data from United States primary care veterinary clinics.

OBJECTIVE: To examine the risk of developing an overweight or obese (O/O) body condition score (BCS) in gonadectomized versus intact dogs and, separately, the impact of age at gonadectomy on O/O outcomes among sterilized dogs. ANIMALS: Dogs were patients of Banfield Pet Hospital in the US from 2013 to 2019. After exclusion criteria were applied, the final sample consisted of 155,199 dogs. PROCEDURES: In this retrospective cohort study, Cox proportional hazards models evaluated associations between O/O and gonadectomy status, sex, age at gonadectomy, and breed size. Models were used to estimate the risk of becoming O/O in gonadectomized versus intact dogs and, separately, to estimate risk of O/O BCS according to age at surgery among gonadectomized dogs. RESULTS: Gonadectomy increased O/O risk for most dogs compared to intact dogs. Unlike most prior findings, O/O hazard ratios among gonadectomized versus intact dogs were larger for males than females. O/O risk varied according to breed size but not linearly. Sterilizing at 1 year old tended to yield a lower O/O risk compared to doing so later. Comparative O/O risk among dogs gonadectomized at 6 months versus 1 year varied by breed size. Overall patterns for obesity related to size were similar to patterns in the O/O analysis. CLINICAL RELEVANCE: Veterinarians are uniquely positioned to help prevent O/O in their patients. Results extend understanding of risk factors for O/O development in dogs. In combination with information about other benefits and risks associated with gonadectomy, these data can help tailor recommendations regarding gonadectomy in individual dogs.

Guidance for management of free-roaming community cats: a bioeconomic analysis.

OBJECTIVES: This study used computer simulation modeling to estimate and compare costs of different free-roaming cat (FRC) management options (lethal and non-lethal removal, trap-neuter-return, combinations of these options and no action) and their ability to reduce FRC population abundance in open demographic settings. The findings provide a resource for selecting management approaches that are well matched for specific communities, goals and timelines, and they represent use of best available science to address FRC issues. METHODS: Multiple FRC management approaches were simulated at varying intensities using a stochastic individual-based model in the software package Vortex. Itemized costs were obtained from published literature and expert feedback. Metrics generated to evaluate and compare management scenarios included final population size, total cost and a cost efficiency index, which was the ratio between total cost and population size reduction. RESULTS: Simulations suggested that cost-effective reduction of FRC numbers required sufficient management intensity, regardless of management approach, and greatly improved when cat abandonment was minimized. Removal yielded the fastest initial reduction in cat abundance, but trap-neuter-return was a viable and potentially more cost-effective approach if performed at higher intensities over a sufficient duration. Of five management scenarios that reduced the final population size by approximately 45%, the three scenarios that relied exclusively on removal were considerably more expensive than the two scenarios that relied exclusively or primarily on sterilization. CONCLUSIONS AND RELEVANCE: FRCs present a challenge in many municipalities, and stakeholders representing different perspectives may promote varying and sometimes incompatible population management policies and strategies. Although scientific research is often used to identify FRC impacts, its use to identify viable, cost-effective management solutions has been inadequate. The data provided by simulating different interventions, combined with community-specific goals, priorities and ethics, provide a framework for better-informed FRC policy and management outcomes.

The Ethics of Innovation: Ethical Decision-Making and Review for Field Studies and Projects Targeting Dogs and Cats.

To date, independent ethical oversight of many companion animal welfare initiatives has been limited and, in some instances, inadequate. Beyond a blurred line between "innovation" and "research," the nature of the work conducted in animal welfare projects is often poorly aligned with established institutional ethical review structures, which are designed for research involving humans or research involving animals and are also focused on industry and academic institutions. This commentary details the struggle of one United States-based nonprofit organization to find ethical guidelines and support for conducting non-traditional field-based animal welfare studies, and subsequent experience establishing an Ethical Review Board to evaluate organizational initiatives. The commentary discusses member selection, materials and processes, and lessons and learnings from the creation and use of an Ethical Review Board. Sharing content of the ethical review process, as well as challenges and learnings from it, is intended to support other organizations and individuals seeking to ensure that innovation for animal welfare consistently meets high ethical standards.

A Long-Term Lens: Cumulative Impacts of Free-Roaming Cat Management Strategy and Intensity on Preventable Cat Mortalities.

This study used a previously developed stochastic simulation model (1) to estimate the impact of different management actions on free-roaming kitten and cat mortality over a 10-year period. These longer-term cumulative impacts have not been systematically examined to date. We examined seven management scenarios, including: (1) taking no action, (2) low-intensity removal, (3) high-intensity removal, (4) low-intensity episodic culling, (5) high-intensity episodic culling, (6) low-intensity trap-neuter-return (TNR), and (7) high-intensity TNR. For each scenario we tracked within the model the number of kittens born, the number of kittens surviving to adulthood, and the number of adults removed using lethal control over the entire 10-year simulation. We further defined all kitten deaths and lethal removal of adults as "preventable" deaths because they could potentially be reduced by certain management actions. Our simulation results suggested that the cumulative number of preventable deaths over 10 years for an initial population of 50 cats is highest for a "no-action" scenario, estimated at 1,000 deaths. It is lowest for a high-intensity TNR scenario, estimated at 32 deaths, a 31-fold difference. For all management scenarios tested, including removal and culling, the model predicted fewer preventable deaths than for a no-action scenario. For all management scenarios, the model predicted that the higher-intensity option (defined in terms of the proportion of animals sterilized or removed within a given time period) would result in fewer preventable deaths over time than the lower-intensity option. Based on these findings, we conclude that management intensity is important not only to reduce populations more quickly, but also to minimize the number of preventable deaths that occur over time. Accordingly, the lessons for the animal welfare community are both encouraging and cautionary. With sufficient intensity, management by TNR offers significant advantages in terms of combined lifesaving and population size reduction. At lower intensity levels, these advantages are greatly reduced or eliminated. We recommend that those who seek to minimize suffering and maximize lifesaving for free-roaming cats attempt to balance prospective goals (i.e., saving lives tomorrow) with proximate goals (i.e., saving lives today), and recognize that thoughtful choice of management strategies can ensure that both of these complementary goals are achieved.

Exploring the Gaps in Practical Ethical Guidance for Animal Welfare Considerations of Field Interventions and Innovations Targeting Dogs and Cats.

Domestic dogs (Canis lupus familiaris) and cats (Felis silvestris catus) are common species targeted by nongovernmental or intergovernmental organizations, veterinarians and government agencies worldwide, for field interventions (e.g., population management, rabies vaccination programs) or innovations (e.g., development of technologies or pharmaceuticals to improve animal welfare). We have a moral responsibility to ensure that the conduct of this work is humane for dogs or cats, and to consider the human communities in which the animals live. Ethical review is widely accepted as being integral to responsible practice, and it is fundamental to good science that underpins innovation. Despite the necessity of field interventions or innovations to advance the welfare of individuals or populations of animals, we found a lack of specific guidance and review processes to help navigate ethical dilemmas surrounding the conduct of such work. This can be detrimental to the wellbeing of animals and their human communities. Here we identify the gaps in existing ethical frameworks (specifically application of Reduction and Refinement principles, challenges of obtaining meaningful informed consent with variations in the quality of human-animal relationships, and limited resources regarding considerations of local stakeholders), and outline the need for additional tools to promote ethical conduct in the field.

Characteristics of cats sterilized through a subsidized, reduced-cost spay-neuter program in Massachusetts and of owners who had cats sterilized through this program.

OBJECTIVE To determine characteristics of cats sterilized through a subsidized, reduced-cost spay-neuter program in Massachusetts and of owners who had their cats sterilized through this program. DESIGN Cross-sectional anonymous survey and telephone interviews. SAMPLE 1,188 (anonymous surveys) and 99 (telephone interviews) cat owners. PROCEDURES Owners who had a cat sterilized at clinics held between January 2006 and December 2008 were invited to complete anonymous surveys. Semistructured telephone interviews were conducted with owners who had a cat sterilized during clinics held in 2009. RESULTS Most cats had never been seen by a veterinarian previously; "too expensive" was the most common reason for this. Total annual household income was significantly associated with the number of times the cat had been examined by a veterinarian and reason why the cat had not been spayed or neutered previously. Most cats were acquired through informal means and without actively being sought, and there was often a time lag between acquisition and sterilization. Undesirable behavior and avoiding pregnancy were primary motivations for neutering and spaying, respectively. Nearly half of owners who indicated they would have had their cat sterilized through a private veterinarian if the clinic had not been available stated that the surgery would have been delayed because of cost. CONCLUSIONS AND CLINICAL RELEVANCE Findings suggested that spay-neuter decisions were related to owner income and procedure cost, that elimination of the reduced-cost spay-neuter program would likely have exacerbated the spay-delay problem, and that gradations of financial need should be considered when evaluating relationships between income and spay-neuter decisions.

Vaccines for feline contraception: GonaCon GnRH-hemocyanin conjugate immunocontraceptive.

VACCINE: GonaCon™ is the trade name of a GnRH-hemocyanin conjugate immunocontraceptive vaccine formulation shown to prevent reproduction and inhibit production of sex hormones in numerous mammalian species for extended durations. GonaCon is currently registered with the US Environmental Protection Agency (EPA) for contraception of female white-tailed deer, and GonaCon™-Equine for female wild horses and burros. Multiple formulations of this GnRH-hemocyanin conjugate immunocontraceptive vaccine have been developed at the National Wildlife Research Center in the United States. EVIDENCE BASE: Three studies employing an early generation vaccine formulation indicated its potential for multi-year contraception of female cats (median duration of effect in excess of 39.7 months). The contraceptive effect for male cats was less predictable and of shorter duration (median duration of effect 14 months). Since these initial feline studies there have been formulation composition changes, and further investigation of the safety, efficacy and duration of this contraceptive vaccine for cats is warranted. FUTURE PROSPECTS: Individual country regulations will determine if GonaCon could be registered for unowned, free-roaming and/or pet cats.

Methods of fertility control in cats: Owner, breeder and veterinarian behavior and attitudes.

OVERVIEW: Fertility control is important for population management of owned and unowned cats, provides health benefits at the individual level and can reduce unwanted sexually dimorphic behaviors such as roaming, aggression, spraying and calling. This article reviews the available evidence regarding European and American veterinarian, owner and pedigree cat breeder attitudes toward both surgical sterilization and non-surgical fertility control. It additionally presents new data on veterinarians' and pedigree cat breeders' use of, and attitudes toward, alternative modalities of fertility control. PROPORTION OF CATS THAT ARE NEUTERED: Within the United States and Europe, the proportion of cats reported to be sterilized varies widely. Published estimates range from 27-93% for owned cats and 2-5% for cats trapped as part of a trap-neuter-return (TNR) program. In some regions and populations of cats, non-surgical fertility control is also used. Social context, cultural norms, individual preferences, economic considerations, legislation and professional organizations may all influence fertility control decisions for cats. NON-SURGICAL METHODS OF FERTILITY CONTROL: Particularly in Europe, a limited number of non-surgical temporary contraceptives are available for cats; these include products with regulatory approval for cats as well as some used 'off label'. Non-surgical methods remove the risk of complications related to surgery and offer potential to treat more animals in less time and at lower cost; they may also appeal to pedigree cat breeders seeking temporary contraception. However, concerns over efficacy, delivery methods, target species safety, duration and side effects exist with current non-surgical options. Research is under way to develop new methods to control fertility in cats without surgery. US and European veterinarians place high value on three perceived benefits of surgical sterilization: permanence, behavioral benefits and health benefits. Non-surgical options will likely need to share these benefits to be widely accepted by the veterinary community.

Ear tips to ear tags: Marking and identifying cats treated with non-surgical fertility control.

CURRENT APPROACHES: Trap-neuter- return (TNR) introduced a humane means of managing free-roaming and feral ('community') cats; it also necessitated a method of marking and identifying these cats as sterilized. Although multiple identification methods have been studied or attempted in the field, ear tipping (or, less commonly, ear notching) has proven to be the best option and is used internationally. However, ear tipping must be performed under general anesthesia, and it conveys only binary information: yes, a cat has gone through a TNR program (and is sterilized); or, no, a cat has not gone through a TNR program (and may or may not be sterilized). FUTURE REQUIREMENTS: Future non-surgical feline fertility control options will require an alternative to ear tipping for identifying community cats, one that does not require anesthesia in order to mark the animal as treated. Long-term contraceptives (vs permanent sterilants) will also require a marker that can denote the time when a cat was last treated. OBJECTIVES AND PROGRESS: To address this need, the Alliance for Contraception in Cats & Dogs is working with an interdisciplinary team from Cornell University, USA, to develop an effective, humane marking method. Their focus is a new generation of ear tag. The prototype design uses different shapes and materials, and a different application process, than tags used to date. The objective is to minimize tag weight, application discomfort, and likelihood of blood loss and infection, while simultaneously allowing for coding of information, including treatment time period.