Key Findings
DPM could theoretically aid rabies control by reducing population turnover and maintaining vaccination coverage. It might also lower bite incidents, attract additional funding, and foster more positive community attitudes toward free-roaming dogs.
However, rabies-endemic countries urgently need better data collection and evaluation of DPM programs. This would enable more informed decision-making and improve program effectiveness. Understanding the costs and benefits of different DPM tools is also crucial for conducting cost-effectiveness analyses and guiding program implementation.
The development of a safe and effective single-dose sterilant for female dogs could greatly enhance the role of DPM in supporting rabies control and elimination efforts, especially in low-income countries.
Summary
Stable dog populations with low turnover rates facilitate sustained vaccination efforts. However, in many countries where canine rabies persists, economic and cultural factors contribute to large free-roaming dog populations, making regular vaccination and rabies elimination challenging.
Dog Population Management (DPM) is a multifaceted approach aimed at improving the health and well-being of free-roaming dogs, reducing public health risks, and potentially controlling population size or turnover. Unlike dog culling, DPM tools are humane and designed for long-term positive impacts. The World Organisation for Animal Health (OIE) recommends DPM as a key component of such programs, as it can enhance the sustainability of rabies control efforts by involving more stakeholders.
The researchers aim to assess the benefits and drawbacks of different DPM tools for rabies control programs. The study, titled “The Role of Dog Population Management in Rabies Elimination—A Review of Current Approaches and Future Opportunities”, reviews the available evidence on the impact of DPM measures on dog health, population size, and the effectiveness of rabies control. Additionally, it discusses the feasibility and costs of implementing these interventions. The goal is to provide program designers with information to help them decide whether to incorporate DPM into their rabies control planning.
Theoretical Benefits of DPM Program For Rabies Control
Theoretical benefits of DPM programs for rabies control can focus on supporting and enhancing rabies vaccination efforts. Mass dog vaccination programs aim for 70% coverage to prevent rabies transmission, but high population turnover, especially among puppies, complicates maintaining this coverage. Effective DPM can support rabies control in several ways:
- Maintaining Vaccination Coverage: Reducing dog population size through DPM makes it easier and less costly to achieve and maintain 70% vaccination coverage. Improved dog health and longevity from DPM can reduce population turnover, making sustained vaccination coverage more feasible.
- Reducing Bite Incidents: Reducing dog-bite incidents through DPM lowers the demand for human post-exposure prophylaxis (PEP), a major cost in rabies-endemic areas. While sterilization may reduce some aggression-related bite incidents, other forms of aggression may persist. DPM programs that include community education and Responsible Dog Ownership (RDO) can help reduce dog-bite incidence by improving community tolerance and reducing provoked bites.
- Increasing Support for Interventions: Combining DPM with rabies control can attract broader public and stakeholder support. DPM measures that improve animal welfare may bring additional partners and funding to rabies control programs, as seen with some animal welfare NGOs.
- Increasing Program Sustainability: Positive public attitudes toward healthier, well-cared-for dogs can increase community participation in rabies vaccination efforts.
Benefits and Drawbacks of Humane DPM Tools
To effectively control rabies, it’s important to reduce the number of dogs and how often the population changes. This makes it easier to vaccinate all dogs. As such, while reproductive control as a DPM tool is a common focus, other strategies that help dogs live longer and reduce population turnover can also support rabies prevention.
I. Reproductive Control
Surgical sterilization is the most common and effective method, offering permanent reproductive control and additional benefits like reduced aggression and increased lifespan. This method is particularly critical for rabies control, as it reduces the population turnover of free-roaming dogs. Non-surgical methods exist but are less practical due to high costs, limited licensing, and potential health risks like uterine infections.
II. Vaccination and Parasite Control
Vaccination against other diseases, along with parasite control, can improve dog health, reduce population turnover, and benefit public health. Routine treatments like ivermectin can also enhance responsible dog ownership (RDO) and community acceptance of dogs.
III. Controlling Access to Food
Researchers conducted a combined population analysis to determine overall dog population demographics in areas where both SRS and HHS were used. The total dog population was calculated as the sum of owned confined dogs, owned semi-confined dogs, owned never-confined dogs, and community dogs.
IV. Community Education, Engagement, and Empowerment
Promoting RDO, alongside accessible vaccination and sterilization services, can significantly reduce free-roaming dogs and associated health risks. Community involvement is crucial for the success and sustainability of DPM programs. Tailored educational materials and long-term engagement are necessary for cultural and behavioral change.
V. Identification, Registration, and Legislation
Identification and registration of dogs, coupled with supportive legislation, can enhance DPM efforts. These measures help enforce rabies vaccination, prevent illegal activities, and manage dog populations effectively. However, they require robust data management, community trust, and enforcement mechanisms.
VI. Shelters, Rehoming Centers, and Euthanasia
While shelters and rehoming centers can reduce free-roaming dog populations, they are costly and often overwhelmed. Euthanasia, ideally reserved for incurably ill or unmanageable dogs, is sometimes used as a population control measure. However, it does not address the root causes of overpopulation and can be distressing for caretakers. Therefore, alternatives to shelters and euthanasia should be fully explored, especially in rabies-endemic regions.
In summary, effective DPM requires a multifaceted approach that includes sterilization, vaccination, food control, community engagement, and supportive legislation. These strategies must be tailored to the local context, with a focus on long-term sustainability and humane treatment of dogs.
Do DPM Tools have a Measurable Impact in Canine Rabies-Endemic Countries?
Assessing the impact of DPM tools in rabies-endemic countries is essential before integrating them into existing rabies control programs. Although community surveys often highlight the need for improved DPM to reduce rabies risk, solid evidence proving the effectiveness of DPM tools in reducing dog population size or turnover, which benefits rabies control, is limited.
Various DPM tools, such as injectable sterilants, waste food removal, leashing and confinement, awareness and legislation, and surgical sterilization, have been implemented with mixed results:
- Injectable Sterilants: Esterilsol™ has been tested in small trials but lacks data on its impact on dog population dynamics or behavior. Sterilizing male dogs alone is unlikely to reduce population size significantly, as reducing female reproductive capacity is more critical.
- Removal of Waste Food Sources: Although waste management is part of some DPM programs, there is no concrete evidence that it significantly impacts dog population size or rabies control.
- Leashing and Confinement: While leashing or confining dogs during rabies outbreaks can reduce dog contact, it is less tolerated once the outbreak ends. Confinement’s value as a DPM tool is limited, especially in low-income countries.
- Awareness and Legislation: “Public awareness and legal measures can significantly aid other dog population management (DPM) efforts, but their individual impact is challenging to quantify. Nonetheless, large-scale, sustainable DPM programs are likely to struggle without public support and legal enforcement. Additionally, 46 of 76 OIE member countries still officially endorse culling dogs during rabies outbreaks, hindering the adoption of DPM. Comprehensive humane laws, such as India’s Animal Birth Control (Dogs) Rules, have demonstrated their effectiveness in promoting DPM programs, emphasizing the importance of supportive legislation.
- Surgical Sterilization: Sterilization, vaccination, and release programs show some success, particularly in India. However, these programs often fail to report impacts on population size or longevity, which affects population turnover. Sustained sterilization efforts are necessary for long-term impact, but many programs lack government support and struggle to expand beyond urban areas.
While DPM tools have potential, their impact on rabies control remains inadequately documented and critically assessed. Comprehensive evaluations and better data sharing are needed to determine the effectiveness of specific DPM interventions.
Cost Considerations
DPM theoretically offers additional benefits to a rabies vaccination program. However, DPM incurs significant costs, requires technical expertise, and demands long-term commitment. Implementing both rabies vaccination and DPM simultaneously can strain resources, potentially hindering the effectiveness of either effort. If DPM detracts from vaccination efforts or diverts funds, it could undermine rabies control. On the other hand, if DPM attracts additional partners or funding, it could positively integrate into rabies control programs.
Data on the field costs of DPM tools are limited, but sterilization programs, often paired with vaccination, can be expensive. For example, an intervention in Colombo City, Sri Lanka, cost over $1 million over four years. While higher throughput programs can reduce per-dog costs, full program costs remain high, particularly in urban areas where economies of scale are more feasible.
Targeting only female dogs for sterilization, along with vaccinating both sexes, could be a more cost-effective way to reduce population size and turnover. However, this strategy is not common, and the scarcity of data on DPM costs and effectiveness limits the ability to assess cost-effectiveness, especially when multiple tools are combined.
Overall, due to the high costs and limited data, sterilization is likely not a cost-effective addition to rabies control programs in most settings. Canine vaccination alone has been found more cost-effective in some models, such as in India. Further research on the costs and benefits of combining sterilization with other interventions, like waste management and educational programs, could provide valuable insights for improving rabies control.
DPM and Rabies Control: Now and in the Future
Humane Dog Population Management (DPM) tools theoretically offer better integration of dogs into communities and the potential for stabilizing or reducing dog populations, which could help maintain vaccination coverage. However, the successful DPM methods used in high-income countries—such as strict breeding and Responsible Dog Ownership (RDO) laws, sterilization, and removal of free-roaming dogs—are difficult to implement in low-income settings. Challenges include a lack of laws or enforcement, limited availability of sterilization services, overwhelmed shelters, and impractical registration due to high turnover.
In settings where there is sufficient political will, funding, and veterinary services, high-throughput sterilization and release programs have been shown to reduce dog populations. However, these programs must reach at least 70% of the dog population to effectively halt rabies transmission. If this coverage is not achieved, additional vaccination efforts are necessary. In resource-limited settings, waste management programs that reduce food resources for free-roaming dogs, along with promotion of RDO, could help reduce dog populations and disease spread, though evidence of their effectiveness is still lacking.
A single-dose sterilant for both sexes could greatly improve DPM and rabies control by offering sterilization during mass vaccination campaigns and enabling sterilization of ownerless dogs without transportation. While a permanent solution would be ideal, even a temporary sterilant lasting 2-4 years could significantly benefit animal welfare and rabies prevention.
Miscellaneous
Data From Study:
–
Year of Publication:
2017
External Link:
Taylor LH, Wallace RM, Balaram D, Lindenmayer JM, Eckery DC, Mutonono-Watkiss B, Parravani E and Nel LH (2017) The Role of Dog Population Management in Rabies Elimination—A Review of Current Approaches and Future Opportunities. Front. Vet. Sci. 4:109. doi: 10.3389/fvets.2017.00109
https://doi.org/10.3389/fvets.2017.00109