Can sterilization help to prevent roaming in owned dogs and cats?

Effects of gonadectomy on the incidence rate of babesiosis and the risk of severe babesiosis in dogs aged 6 months and older at a veterinary academic hospital in South Africa: A case-control and retrospective cohort study

Gonadectomy in dogs is associated with changes in risks of a variety of non-infectious health conditions, but few studies have examined its effects on infectious disease outcomes. The objectives of our study were to estimate the causal effect of gonadectomy on the incidence rate of babesiosis diagnosis, and on the risk of severe babesiosis in diagnosed cases, in dogs 6 months and older seen at a veterinary academic hospital in South Africa from 2013 through 2020. To estimate the effect of gonadectomy on the incidence rate of babesiosis diagnosis in dogs, we conducted a case-control study with incidence density sampling of dogs seen through the hospital's primary care service, adjusting for sex, age, breed category and weight. We identified 811 cases and selected 3244 time-matched controls. To estimate the effect of gonadectomy on disease severity in dogs with babesiosis, we conducted a retrospective cohort study among all dogs with a diagnosis of babesiosis (n=923), including these 811 cases and a further 112 referred to the hospital, also adjusting for sex, age, breed category and weight. Gonadectomy substantially reduced the incidence rate of babesiosis (total effect incidence rate ratio [IRR] 0.5; 95 % confidence interval [CI] 0.41-0.60) and the risk of severe babesiosis among diagnosed dogs (total effect risk ratio [RR] 0.72; 95 % CI 0.60-0.86). Tipping point sensitivity analysis shows that these effect estimates are robust to unmeasured confounding bias. There was no evidence for modification of the effect of gonadectomy by sex, with effect estimates qualitatively similar for males and females for both outcomes. Compared to females, males had a higher incidence rate of babesiosis (IRR 1.74; 95 % CI 1.49-2.04) and a higher risk of severe disease (RR 1.12; 95 % CI 0.98-1.28). In conclusion, our study shows a robust protective effect of gonadectomy on the incidence and severity of babesiosis in both male and female dogs 6 months of age and older, and contributes important evidence to the debate on the overall risks and benefits of gonadectomy to dogs in this population.

An assessment of the owned canine and feline demographics in Chile: registration, sterilization, and unsupervised roaming indicators

The global rise in companion animal populations, particularly dogs and cats, is driven by emotional and social benefits for owners, and their population management is becoming critically important to avoid a plethora of adverse effects on themselves, humans, and wildlife. We estimated the size and density of the owned canine and feline population in Chile and evaluated the status of microchipping, registration, sterilization rates, and the proportion of owned animals that roam unsupervised. A cross-sectional household survey in 36 districts was conducted and standard inferential statistics was employed to analyze differences between cats and dogs, sexes within each species, and between rural and urban areas. Additionally, two negative binomial models with mixed effects were developed to predict the number of dogs and cats per households. Two methods were used to compare population size estimates at the country level, multiplying: (1) the estimated mean number of companion animals per household by the estimated number of households at the country level, and (2) the estimated human:dog and human:cat ratios by the total human population. The study involved 6333 respondents, of which 76% (74% urban; 83% rural) owned companion animals (dogs and/or cats). Individuals in rural multi-person households increase the probability of owning dogs and/or cats. Additionally, women exhibit a greater inclination towards cat and dog ownership compared to men, while those over 30 years old demonstrate lower rates of companion animal ownership in contrast to the 18-30 age group for both species. The overall human:dog and human:cat ratios estimated were 2.7:1, and 6.2:1, respectively. The estimated total number of owned dogs and cats in Chile ranged from 9.6 to 10.7 million, depending on the methodological approach, while national median density of companion animals was 12 dogs per km2 (ranging from 0.02 to 7232) and 5 cats per km2 (ranging from 0.01 to 3242). This nationwide study showed one of the highest percentages of households with companion animals in Latin America and relatively low registration and sterilization rates, highlighting the need to strength long-term public policies to control populations of companion animals and promote responsibility in pet ownership.

Comparative Study of Free-Roaming Domestic Dog Management and Roaming Behavior Across Four Countries: Chad, Guatemala, Indonesia, and Uganda

Dogs play a major role in public health because of potential transmission of zoonotic diseases, such as rabies. Dog roaming behavior has been studied worldwide, including countries in Asia, Latin America, and Oceania, while studies on dog roaming behavior are lacking in Africa. Many of those studies investigated potential drivers for roaming, which could be used to refine disease control measures. However, it appears that results are often contradictory between countries, which could be caused by differences in study design or the influence of context-specific factors. Comparative studies on dog roaming behavior are needed to better understand domestic dog roaming behavior and address these discrepancies. The aim of this study was to investigate dog demography, management, and roaming behavior across four countries: Chad, Guatemala, Indonesia, and Uganda. We equipped 773 dogs with georeferenced contact sensors (106 in Chad, 303 in Guatemala, 217 in Indonesia, and 149 in Uganda) and interviewed the owners to collect information about the dog [e.g., sex, age, body condition score (BCS)] and its management (e.g., role of the dog, origin of the dog, owner-mediated transportation, confinement, vaccination, and feeding practices). Dog home range was computed using the biased random bridge method, and the core and extended home range sizes were considered. Using an AIC-based approach to select variables, country-specific linear models were developed to identify potential predictors for roaming. We highlighted similarities and differences in term of demography, dog management, and roaming behavior between countries. The median of the core home range size was 0.30 ha (95% range: 0.17-0.92 ha) in Chad, 0.33 ha (0.17-1.1 ha) in Guatemala, 0.30 ha (0.20-0.61 ha) in Indonesia, and 0.25 ha (0.15-0.72 ha) in Uganda. The median of the extended home range size was 7.7 ha (95% range: 1.1-103 ha) in Chad, 5.7 ha (1.5-27.5 ha) in Guatemala, 5.6 ha (1.6-26.5 ha) in Indonesia, and 5.7 ha (1.3-19.1 ha) in Uganda. Factors having a significant impact on the home range size in some of the countries included being male dog (positively), being younger than one year (negatively), being older than 6 years (negatively), having a low or a high BCS (negatively), being a hunting dog (positively), being a shepherd dog (positively), and time when the dog was not supervised or restricted (positively). However, the same outcome could have an impact in a country and no impact in another. We suggest that dog roaming behavior is complex and is closely related to the owner's socioeconomic context and transportation habits and the local environment. Free-roaming domestic dogs are not completely under human control but, contrary to wildlife, they strongly depend upon humans. This particular dog-human bound has to be better understood to explain their behavior and deal with free-roaming domestic dogs related issues.

Comparative Study of Free-Roaming Domestic Dog Management and Roaming Behavior Across Four Countries: Chad, Guatemala, Indonesia, and Uganda

Dogs play a major role in public health because of potential transmission of zoonotic diseases, such as rabies. Dog roaming behavior has been studied worldwide, including countries in Asia, Latin America, and Oceania, while studies on dog roaming behavior are lacking in Africa. Many of those studies investigated potential drivers for roaming, which could be used to refine disease control measures. However, it appears that results are often contradictory between countries, which could be caused by differences in study design or the influence of context-specific factors. Comparative studies on dog roaming behavior are needed to better understand domestic dog roaming behavior and address these discrepancies. The aim of this study was to investigate dog demography, management, and roaming behavior across four countries: Chad, Guatemala, Indonesia, and Uganda. We equipped 773 dogs with georeferenced contact sensors (106 in Chad, 303 in Guatemala, 217 in Indonesia, and 149 in Uganda) and interviewed the owners to collect information about the dog [e.g., sex, age, body condition score (BCS)] and its management (e.g., role of the dog, origin of the dog, owner-mediated transportation, confinement, vaccination, and feeding practices). Dog home range was computed using the biased random bridge method, and the core and extended home range sizes were considered. Using an AIC-based approach to select variables, country-specific linear models were developed to identify potential predictors for roaming. We highlighted similarities and differences in term of demography, dog management, and roaming behavior between countries. The median of the core home range size was 0.30 ha (95% range: 0.17-0.92 ha) in Chad, 0.33 ha (0.17-1.1 ha) in Guatemala, 0.30 ha (0.20-0.61 ha) in Indonesia, and 0.25 ha (0.15-0.72 ha) in Uganda. The median of the extended home range size was 7.7 ha (95% range: 1.1-103 ha) in Chad, 5.7 ha (1.5-27.5 ha) in Guatemala, 5.6 ha (1.6-26.5 ha) in Indonesia, and 5.7 ha (1.3-19.1 ha) in Uganda. Factors having a significant impact on the home range size in some of the countries included being male dog (positively), being younger than one year (negatively), being older than 6 years (negatively), having a low or a high BCS (negatively), being a hunting dog (positively), being a shepherd dog (positively), and time when the dog was not supervised or restricted (positively). However, the same outcome could have an impact in a country and no impact in another. We suggest that dog roaming behavior is complex and is closely related to the owner's socioeconomic context and transportation habits and the local environment. Free-roaming domestic dogs are not completely under human control but, contrary to wildlife, they strongly depend upon humans. This particular dog-human bound has to be better understood to explain their behavior and deal with free-roaming domestic dogs related issues.

Effects of Gender, Sterilization, and Environment on the Spatial Distribution of Free-Roaming Dogs: An Intervention Study in an Urban Setting

Information concerning the factors affecting the circulation and distribution of free-roaming dogs is crucial in developing control actions and limiting the spread of zoonoses. The present study analyzes the influence of gender, sterilization, and environment on the spatial distribution of free-roaming dogs in urban settings. Animals were captured/recaptured in seven consecutive morning sampling efforts conducted at 2-monthly intervals in control and intervention areas in a medium-size town in southeastern Brazil. Capture locations were georeferenced and captured animals were microchipped before being released at their original capture sites. Dogs captured in the intervention area were subjected additionally to surgical sterilization prior to release. Home range (HR) areas were calculated by applying the minimum convex polygon method to dogs that had been captured at least three times. Land coverage zones were determined from satellite images and overlaid on maps of the study areas along with the locations of 22 commercial food outlets. HR areas showed a global mean of 448 m² and a median of 28 m², values that were smaller than those reported previously for dogs in rural regions. The median HR of females (64.m²) was higher than that of males (15 m²), while median HRs of animals in the control and intervention areas were similar (27 and 28.5 m², respectively). Variability of HR was high, although animals with small HRs predominated. Free-roaming dogs grouped primarily in urbanized and transitional regions, and their spatial distribution was positively correlated with locations of commercial food outlets. While sterilization did not influence HR size, the search for food was a key factor in determining mobility and spatial aggregation of free-roaming dogs. Our findings are pertinent in understanding the ecology of free-roaming dogs in urban environments and will be applicable to strategies aimed at promoting animal welfare and preventing the dissemination of zoonoses.