Dynamic modeling of female neutering interventions for free-roaming dog population management in an urban setting of southeastern Iran

Environmental contamination with feces of free-roaming dogs and the risk of transmission of Echinococcus and Taenia species in urban regions of southeastern Iran

BACKGROUND

Dogs are the most important definitive hosts of zoonotic taeniid helminths worldwide. Different Echinococcus and Taenia species of domestic and wild carnivores pose a potential risk to human population. High populations of free-roaming dogs (FRDs) in urban areas of Iran and widespread contamination of the environment with dog feces is a potential source of infecting people living in the urban regions with cystic echinococcosis (CE). Our knowledge on the risk of CE transmission in the urban settings in the endemic regions is limited. The present study surveyed the species and genotypes of E. granulosus sensu lato and other taeniids by examining feces of free-roaming dogs in the urban areas in the city of Kerman, southeastern Iran.

METHODS

The city was divided into 100 consecutive blocks of which 25 blocks were randomly selected. Fecal samples of FRDs were counted, mapped and fresh samples were collected. Then Zinc chloride flotation, and sequential sieving was performed, and the samples were examined under an inverted microscope. Single individual taeniid eggs were isolated, partial nad1 gene was amplified and sequenced to identify species and genotypes.

RESULTS

In total 5607 fecal samples of dogs were mapped and 83 fresh samples were collected. Taeniid eggs were detected in nine fecal samples (10.8%) from seven out of the 25 city blocks (28.0%). Echinococcus eggs were found in four samples (4.8%) from three city blocks, two samples containing E. granulosus sensu stricto (2.4%), two samples containing E. canadensis G6/7 (2.4%). In addition, three samples contained eggs of Taenia hydatigena (3.6%), and one sample of Taenia serialis (1.2%).

CONCLUSIONS

This study documented the potential risk of CE transmission to humans resulting from the feces of dogs roaming freely in urban areas.

Spatiotemporal analysis of a population management intervention for dogs and cats in a municipality in central Mexico

Background and Aim

The overpopulation of dogs and cats has generated socioeconomic, political, and animal welfare problems, in addition to an important public health problem, due to the risk of zoonotic diseases. This study aimed to analyze the spatiotemporal coverage of canine and feline sterilization services provided by a governmental agency in the rural and urban areas of the municipality of Tequisquiapan, Querétaro.

Materials and Methods

This cross-sectional study was conducted in Tequisquiapan's municipality, Querétaro, Mexico, from July 2019 to September 2022. The total number of sterilized dogs and cats was obtained from the monthly records of the Tequisquiapan Animal Health and Welfare Services Center (CESSBA, by its Spanish acronym). The collected information was related to the sterilized animals (species and sex) and their responsible guardians (sex and address). Access to dog and cat sterilization services was assessed using a geographic information system. Kernel density and directional ellipse tools were used to analyze the CESSBA coverage of care. Indicators were estimated to compare magnitudes and changes at the census tract level.

Results

A total of 4,489 animals were sterilized, with n = 2,611 (58%) dogs, of which 1,939 were female and 672 were male. The remaining n = 1,878 animals were cats, representing 42% of the total, with 1,257 females and 621 males. Up to 73% of the sterilized animals were owned by women. The population management of dogs and cats allowed us to increase the territorial coverage from 71.8% in 2019 to 92.3% in 2022. According to the temporal analysis (2019-2022), there was an annual upward trend in the number of sterilizations performed by CESSBA, with a rate of between 55.6 and 94.3 registered sterilizations per 100 inhabited dwellings and between 166.4 and 302.8 registered sterilizations per 1000 inhabitants.

Conclusion

The analysis of the dog and cat sterilization service coverage revealed an upward trend, consisting of an increase in accessibility and participation of responsible caregivers who resided in both urban and rural areas of Tequisquiapan. Although it was not possible to evaluate the impact of the program, the use of georeferenced data and geospatial analysis showed that it can support the control of animal overpopulation.

Demographics and tenure of the Chilean urban dog population. A mathematical model

BACKGROUND

Irresponsible dog ownership in urban areas is a public health concern with significant implications for human, animal, and environmental welfare. Factors such as abandonment, variations in adoption, insufficient supervision, emerging identification initiatives, and collective feeding impact the growth of stray dog populations and the transmission of diseases. Developing a modeling tool to understand the dynamics of canine population growth and the effect of human behavior on this phenomenon is essential.

METHODS

An ordinary differential equation model was developed to depict the growth dynamics and movements of urban dog populations, distinguishing between those with owners (restricted and semi-restricted) and those without (stray and community dogs). Two equilibrium states of the system were analyzed: with and without the presence of individually owned dogs. An increase rate for the population of individually owned dogs was calculated, and a local sensitivity analysis was conducted to assess the impact of parameters on the reduction of this population. Additionally, two global sensitivity analysis methods were used to evaluate the simultaneous influence of the parameters.

RESULTS

Findings indicate that system equilibrium depends on various dog categories. Although total eradication of stray and community dogs is unlikely, equilibrium levels are directly related to subpopulation growth rates, responsible ownership practices, and adoption and abandonment rates. The growth rates of the population of dogs without individual owners have a direct and proportional influence on their regulation, while adoption rates have an inverse and proportional effect. The study, through global sensitivity analysis, identifies key parameters for each dog subpopulation. For restricted dogs, environmental carrying capacity is the most variable factor; for semi-restricted dogs, awareness of responsible ownership is crucial. The abandonment of restricted dogs significantly impacts stray dog dynamics, while the transition from stray to community status is an important variable factor for community dogs.

CONCLUSION

Addressing the situation of unowned dogs requires a collective effort to reduce risks associated with the spread of zoonotic diseases, environmental pollution, and biodiversity loss, thus contributing to public health and environmental conservation.

Reinfection of farm dogs following praziquantel treatment in an endemic region of cystic echinococcosis in southeastern Iran

Cystic Echinococcosis (CE) as a prevalent tapeworm infection of human and herbivorous animals worldwide, is caused by accidental ingestion of Echinococcus granulosus eggs excreted from infected dogs. CE is endemic in the Middle East and North Africa, and is considered as an important parasitic zoonosis in Iran. It is transmitted between dogs as the primary definitive host and different livestock species as the intermediate hosts. One of the most important measures for CE control is dog deworming with praziquantel. Due to the frequent reinfection of dogs, intensive deworming campaigns are critical for breaking CE transmission. Dog reinfection rate could be used as an indicator of the intensity of local CE transmission in endemic areas. However, our knowledge on the extent of reinfection in the endemic regions is poor. The purpose of the present study was to determine E. granulosus reinfection rate after praziquantel administration in a population of owned dogs in Kerman, Iran. A cohort of 150 owned dogs was recruited, with stool samples collected before praziquantel administration as a single oral dose of 5 mg/kg. The re-samplings of the owned dogs were performed at 2, 5 and 12 months following initial praziquantel administration. Stool samples were examined microscopically using Willis flotation method. Genomic DNA was extracted, and E. granulosus sensu lato-specific primers were used to PCR-amplify a 133-bp fragment of a repeat unit of the parasite genome. Survival analysis was performed using Kaplan-Meier method to calculate cumulative survival rates, which is used here to capture reinfection dynamics, and monthly incidence of infection, capturing also the spatial distribution of disease risk. Results of survival analysis showed 8, 12 and 17% total reinfection rates in 2, 5 and 12 months following initial praziquantel administration, respectively, indicating that 92, 88 and 83% of the dogs had no detectable infection in that same time periods. The monthly incidence of reinfection in total owned dog population was estimated at 1.5% (95% CI 1.0-2.1). The results showed that the prevalence of echinococcosis in owned dogs, using copro-PCR assay was 42.6%. However, using conventional microscopy, 8% of fecal samples were positive for taeniid eggs. Our results suggest that regular treatment of the dog population with praziquantel every 60 days is ideal, however the frequency of dog dosing faces major logistics and cost challenges, threatening the sustainability of control programs. Understanding the nature and extent of dog reinfection in the endemic areas is essential for successful implementation of control programs and understanding patterns of CE transmission.

Exploring the spatial pattern of animal bites in Iran (2021-2022)

OBJECTIVE

Knowledge of the spatial pattern of animal bites can be helpful for targeted resource allocation and to develop and deliver effective intervention programs. The aim of this study was to explore the spatial pattern of the animal bites in Iran during 2021-2022.

METHODS

Animal bite cases from all provinces and counties in Iran were obtained from a nationally based registry. Global Moran's I was applied to check spatial autocorrelation. The spatially adjusted standardized incidence ratios (SIRs) were estimated using the Besag, York, and Mollie (BYM) model. Spatial clusters were identified by local indicators of spatial association (LISA) and purely spatial scan statistic.

RESULTS

A total of 260,470 animal bites were registered during the study period. There was a positive spatial autocorrelation (global Moran's I=0.27, p-value=0.001). The majority of SIRs greater than 1.00 was found in counties in the northern belt of Iran (e.g., observed greater than expected animal bites). LISA found that approximately 7% of counties in the north and northeast, 18% in the west and south, and 3% in the central part of Iran were significant hot spots, cold spots, and spatial outliers (p-value≤0.05). Spatial scan statistic detected primary hot spot cluster in the counties in the Mazandaran and Alborz provinces (Relative Risk=2.56, p-value<0.001), while primary cold spot cluster involved counties in Kurdistan and Kermanshah province (0.37, <0.001).

CONCLUSION

Animal bites were unevenly distributed in Iran. Further prevention and control programs as well as appropriately resource allocation are needed in order to reduce the observed animal bites spatial disparity.

Assessing multiple free-roaming dog control strategies in a flexible agent-based model

Management of free-roaming dog populations is required to mitigate the threat of pathogens like rabies, minimize conflict with people, wildlife, and livestock and improve dog welfare however there are multiple strategies currently employed including sterilization, vaccination, and lethal removal. This work describes an agent-based stochastic model, 'StreetDogSim' that can be used as a planning tool to investigate the predicted impact of different strategies with variable implementation approaches and adjustable parameters to match local conditions. Here, we explore the effects of different management strategies with additional variation in their duration, intensity, and vaccine quality on important population metrics such as overall size, demographics, vaccination coverage, time until effective population suppression, and duration of suppression. Under most model parameterizations, a strategy that targets females for sterilization with vaccination outperforms all other options with respect to population control and demographic changes.

You Are Not Welcome! A Media Analysis of Risk Factors, Prevalence and Management of Free-Roaming Dogs in Iran

History has witnessed a long-term relationship between humans and animals. Historical documents and modern findings prove that humans' needs to use animals for companions or services are commonplace in many parts of the world, leading to the domestication of certain animals. Yet, modern societies have degraded many natural habitats for wildlife, confining them to small patches of landscapes or urban areas. Whether a domesticated/free-roaming animal or a wild species, their close contact with humans can create cumbersome situations for both species. This paper explores a link between online media content and on-the-ground efforts to manage free-roaming dogs as a rare case study. As indicated by news articles, the municipal costs of managing free-roaming dogs in Iranian cities have increased, and this can potentially derail the control of such dogs in the long run. This paper lays out pivotal factors for recent increasing human-animal encounters, which have led to many challenges (e.g., rabies) across cities in Iran. We show that some urban features (e.g., topography) can influence the presence and behaviours of free-roaming animals in the cities. The findings of this paper can be related to other developing countries where the plague of rabies is rising.

Impact Assessment of Free-Roaming Dog Population Management by CNVR in Greater Bangkok

A high-intensity catch, neuter, vaccinate and return (CNVR) intervention was used over 5 years to manage the free-roaming dog population of Greater Bangkok, using nearly 300,000 CNVR operations across six provinces. An evaluation was conducted using multiple methods to assess the impact of this intervention, including clinical data, an observational street survey, an online attitude survey and reported cases of dog rabies confirmed with laboratory testing. The evaluation found evidence of a reduction in free-roaming dog density over time (24.7% reduction over 5 years), a reduction in dog rabies cases (average reduction of 5.7% rabies cases per month) and an improvement in dog-human relationships (a 39% increase per year in free-roaming dogs with visible signs of ownership or care and a perception of less trouble with free-roaming dogs in districts benefiting from CNVR). The CNVR intervention appears to have been effective at reducing the current free-roaming dog population and minimizing one future source of free-roaming dogs by limiting breeding of dogs accessible on the streets. However, there is evidence that other sources of free-roaming dogs exist, presumed to be predominately abandoned or lost owned dogs that were previously inaccessible to the CNVR intervention because they were ordinarily confined or living outside the project area. Hence, fully effective dog population management will require further interventions targeting owned dogs in addition to this CNVR effort.

A wicked environmental challenge: collaboration network for free-ranging dog management in an urban environment

Invasive species possess wide-ranging social and ecological impacts globally. Although the ecological impacts are well studied, social aspects especially in developing countries are often poorly understood. Free-ranging dogs (FRDs) (Canis familiaris) are the most abundant carnivore on earth with a high level of invasion. Recently, the presence of FRDs in the Jiroft city in southern Iran has increased, and local managers have not yet developed a coherent management plan. Given the high rate of human bites by FRDs in this region, a principled management plan with integrated collaboration between the relevant organizations is necessary. To better understand collaboration networks, we interviewed employees of three relevant governmental organizations about their collaboration with other organizations toward FRD management. Our objective in this study was to (1) assess the collaboration between the municipality, provincial offices of veterinary medicine, and health network and (2) predict the behavioral tendencies of network actors based on their current position in the FRD management network. Although most employees have never worked together to manage FRDs, our results showed that most of the interviewees did not evaluate the role of other organizations in FRD management as beneficial. Moreover, the current assessment of the employees of the two municipal and health organizations affects their current collaboration in the management of FRDs. Also, the current collaboration has a significant impact on their intention to collaborate in the future. We make suggestions for improving collaboration in managing FRDs in this region.

Owned dog population size and ownership patterns in Costa Rica

Dogs (Canis lupus familiaris) are one of the most common pets around the world but ownership patterns and human-dog interactions have been changing, particularly in developing nations. We conducted household surveys in Costa Rica to characterize dog ownership, the owned dog population, where dogs were confined at night and in the morning, and behaviors regarding selected dog care issues. We also compared these results to similar questionnaires used in Costa Rica over the past 20 years. We found 76% of households in Costa Rica owned at least one dog and on average there were about 1.4 dogs owned per household. These dog ownership rates are higher than previous estimates. The probability of owning a dog was highest on farms and lowest in single family dwellings without a yard, higher among respondents that owned their homes and decreasing with increasing human population density The total number of owned dogs in Costa Rica was estimated to be 2,222,032 (95% confidence intervals: 1,981,497-2,503,751). The sterilization rate for homed dogs in 2020 was approximately 62% (females: 67%, males: 61%) which is higher than the 18% of owned dogs that were sterilized in a 2003 survey. Overall, only 1.2% (95% CI: 0.3-2.5%) of owned dogs slept on the street with a slightly higher proportion on the street at 8 am. The number of owned dogs roaming the streets at night nation-wide was estimated to be 27,208 (95% CI: 7,557-56,619) compared to 43,142 (95% CI: 20,118-73,618) on the street at 8 am. The number of unowned free-roaming dogs in Costa Rica has never been estimated but we can generate some idea of the size of the unowned dog population by determining the proportion of free-roaming dogs on the street wearing collars. There was a negative relationship between human population density and owned dogs being on the street meaning fewer dogs roam the streets in highly populated areas compared to less populated areas. Overall, we identify trends against which future progress can be measured and provide information that are critical in designing effective humane dog management programs in Costa Rica in the future.