Key Findings
From 2016 to 2021, Soi Dog Foundation conducted over 289,000 sterilization surgeries. As a result, they estimated a 24% decline in dog density in the treatment districts, alongside a 5.7% monthly reduction in rabies cases in Bangkok during the same period.
Researchers confirmed the numerical decrease in dog density using a mix of sterilization records, street surveys, and attitude surveys.
Approximately 20% of respondents reported that they or their family members feed street dogs. Conversely, nearly 60% stated that they find the street dog situation unacceptable. decrease in dog density using a mix of sterilization records, street surveys, and attitude surveys.
Summary
The Greater Bangkok area in Thailand includes both urban and peri-urban regions, characterized by a high density of human populations and a substantial presence of free-roaming dogs. While these dogs are generally tolerated and often fed by kindhearted Bangkok citizens, complaints and the risk of rabies persist.
In response, the Soi Dog Foundation, in collaboration with Dogs Trust Worldwide, has been implementing a Catch-Neuter-Vaccinate-Return (CNVR) program in Bangkok. This program uses a high-intensity, rotational approach, targeting each district until at least 80% of the free-roaming dog population has been reached before moving to neighbouring districts. This strategy was adopted because low CNVR coverage across the entire area may be less effective in achieving herd immunity for rabies control and in reducing the dog population.
This study, titled “Impact Assessment of Free-Roaming Dog Population Management by CNVR in Greater Bangkok,” aimed to evaluate the effectiveness of this CNVR approach. To do so, researchers relied on several key indicators: the density of free-roaming dogs, their breeding activity, the incidence of rabies cases, and the perceptions and care of these dogs by local citizens.
The researchers utilized multiple methods to measure changes. In addition to data collected from the CNVR program, the study employed a combination of street surveys and attitude surveys to gather the required information. The street surveys, conducted in 2016, 2020, and 2021, provided insights into the number of free-roaming dogs along twenty surveyed routes. Surveyors also recorded the proportion of lactating females and puppies. The attitude surveys focused on several variables: whether households regularly fed street dogs, perceptions of changes in dog numbers over the previous four years, acceptance of street dogs, experiences of trouble with free-roaming dogs in the previous month, and perceptions of trouble today compared to four years earlier.
Campaign Results & Assessment
From 2016 to 2021, the CNVR project sterilized a total of 289,969 dogs. Of the 195,311 dogs with recorded data, 60% were female and 40% were male. Among these dogs, 51% were community dogs, 25% were owned roaming dogs, and 23% were unowned. Based on sterilization records and data from the 2016 survey, researchers estimated a mean sterilization rate of 47%.
Dog Density
Using data from the street surveys, researchers observed a decrease in recorded dog density, falling from 2.66 dogs per kilometer in 2016 to 2.47 in 2020 and 1.83 in 2021. Public perception supported this decline; when asked to recall the situation from four years ago, the most common perception (31%) from those who lived in areas with CNVR was that “there used to be more dogs on my street.” This contrasts with areas without CNVR, where the most common perception (28%) was “there were far fewer dogs on my street.”
Furthermore, across all routes, surveyors noted a significant decrease in the proportion of lactating females, from 23.4% in 2016 to 0.9% in 2020 and 1.4% in 2021. The proportion of puppies also declined from 4.8% in 2016 to 1.3% in 2020 and 1.1% in 2021.
Rabies Cases
Over the five years of the CNVR project, there were a total of 234 laboratory-confirmed rabies cases in Greater Bangkok. Researchers found that increased CNVR efforts were correlated with a decline in rabies cases: as CNVR activities ramped up over the years, rabies cases declined accordingly.
Public Perception Of Free-Roaming Dogs
The researchers reviewed public perception of street dogs using the attitude survey. In total, 19.8% of respondents confirmed that either they or someone in their household feeds street dogs. Additionally, 59% of participants reported not being accepting of the current dog situation, with no notable differences between those living in CNVR-operational districts and those living outside these areas.
However, when asked if they had been troubled by free-roaming dogs in the past month, fewer respondents (37%) living within CNVR-operational districts reported issues, compared to 50% of respondents living outside CNVR-operational districts.
This scenario highlighted the added complexity for ABC programs to achieve sustainable population control and vaccination coverage under real-world conditions
With a significant decrease in dog density (24.7% reduction over 5 years) and a notable drop in dog rabies cases (average reduction of 5.7% per month), the researchers concluded that the CNVR program was successful. However, they noted that while CNVR can prevent inbreeding among street dogs, it cannot stop the increase of free-roaming dogs from other sources, such as abandonment. This underscores that CNVR is only one piece of the larger puzzle, and effective dog population management would require significant interventions targeting the owned dog population as well.
Data From Study:
Dog Population Management / Case Studies / Bangkok, CNVR (2023)
Year of Publication:
2023
External Link:
Hiby, E.; Rungpatana, T.; Izydorczyk, A.; Rooney, C.; Harfoot, M.; Christley, R. Impact Assessment of Free-Roaming Dog Population Management by CNVR in Greater Bangkok. Animals 2023, 13, 1726.
https://doi.org/10.3390/ani13111726