Spatial and temporal activity patterns of owned, free-roaming dogs in coastal eastern Australia.

Dogs are ubiquitous and strongly associated with human communities, but many roam freely, away from the owners' property and control. Free-roaming owned dogs can pose risks through disease transmission to and from other dogs, attacking domestic animals, fauna or humans, and involvement in road accidents. However, little research has focused on understanding their movement ecology, thereby hindering the development of effective management plans. We modified store-bought GPS collars and used them to track a sample of 43 free-roaming owned dogs from peri-urban sites in north-east New South Wales and south-east Queensland, Australia. Our aim was to quantify the activity ranges of owned dogs and the distances they travelled, whether free-roaming or accompanying people, and to identify some associated factors. The total activity ranges of our sample of dogs were variable (0.80-1776.20 ha), and the mean daily activity range of collared dogs was relatively large (7.23 ± 11.99 ha), with mean daily accumulated distances travelled ranging from 0.25 to 4.81 km (mean = 1.95 ± 1.10 km). The dogs exhibited two temporal activity peaks, one between 0700 and 1000 and a second between 1600 and 1900 hrs. Most human-mediated dog movements were short in duration, ranging from 45 min to 6 h, with dogs moving an average of 48.60 ± 64.00 km, but up to 329.00 km from their home. The large activity ranges and relatively long movements in this sample of free-roaming owned dogs suggests they have potential to contribute to the spread of exotic and endemic zoonotic and canid diseases in the peri-urban coastal regions of eastern Australia. The baseline information collected here is crucial to our understanding of disease transmission among peri-urban dogs, and modelling spread within and between communities. Additionally, it provides valuable information for authorities seeking to improve management of free-roaming owned dogs.

Contact rates of wild-living and domestic dog populations in Australia: a new approach.

Dogs (Canis familiaris) can transmit pathogens to other domestic animals, humans and wildlife. Both domestic and wild-living dogs are ubiquitous within mainland Australian landscapes, but their interactions are mostly unquantified. Consequently, the probability of pathogen transfer among wild-living and domestic dogs is unknown. To address this knowledge deficit, we established 65 camera trap stations, deployed for 26,151 camera trap nights, to quantify domestic and wild-living dog activity during 2 years across eight sites in north-east New South Wales, Australia. Wild-living dogs were detected on camera traps at all sites, and domestic dogs recorded at all but one. No contacts between domestic and wild-living dogs were recorded, and limited temporal overlap in activity was observed (32 %); domestic dogs were predominantly active during the day and wild-living dogs mainly during the night. Contact rates between wild-living and between domestic dogs, respectively, varied between sites and over time (range 0.003-0.56 contacts per camera trap night). Contact among wild-living dogs occurred mainly within social groupings, and peaked when young were present. However, pup emergence occurred throughout the year within and between sites and consequently, no overall annual cycle in contact rates could be established. Due to infrequent interactions between domestic and wild-living dogs, there are likely limited opportunities for pathogen transmission that require direct contact. In contrast, extensive spatial overlap of wild and domestic dogs could facilitate the spread of pathogens that do not require direct contact, some of which may be important zoonoses.

Rabies disease dynamics in naïve dog populations in Australia.

Currently, Australia is free from terrestrial rabies but an incursion from nearby Indonesia, where the virus is endemic, is a feasible threat. Here, we aimed to determine whether the response to a simulated rabies incursion would vary between three extant Australian dog populations; free-roaming domestic dogs from a remote indigenous community in northern Australia, and free-roaming domestic and wild dogs in peri-urban areas of north-east New South Wales. We further sought to predict how different management strategies impacted disease dynamics in these populations. We used simple stochastic state-transition models and dog demographic and contact rate data from the three dog populations to simulate rabies spread, and used global and local sensitivity analyses to determine effects of model parameters. To identify the most effective control options, dog removal and vaccination strategies were also simulated. Responses to simulated rabies incursions varied between the dog populations. Free-roaming domestic dogs from north-east New South Wales exhibited the lowest risk for rabies maintenance and spread. Due to low containment and high contact rates, rabies progressed rapidly through free-roaming dogs from the remote indigenous community in northern Australia. In contrast, rabies remained at relatively low levels within the north-east New South Wales wild dog population for over a year prior to an epidemic. Across all scenarios, sensitivity analyses revealed that contact rates and the probability of transmission were the most important drivers of the number of infectious individuals within a population. The number of infectious individuals was less sensitive to birth and death rates. Removal of dogs as a control strategy was not effective for any population modelled, while vaccination rates in excess of 70% of the population resulted in significant reductions in disease progression. The variability in response between these distinct dog groups to a rabies incursion, suggests that a blanket approach to management would not be effective or feasible to control rabies in Australia. Control strategies that take into account the different population and behavioural characteristics of these dog groups will maximise the likelihood of effective and efficient rabies control in Australia.

Effects of sex and reproductive state on interactions between free-roaming domestic dogs.

Free-roaming dogs (Canis familiaris) are common worldwide, often maintaining diseases of domestic pets and wildlife. Management of these dogs is difficult and often involves capture, treatment, neutering and release. Information on the effects of sex and reproductive state on intraspecific contacts and disease transmission is currently lacking, but is vital to improving strategic management of their populations. We assessed the effects of sex and reproductive state on short-term activity patterns and contact rates of free-roaming dogs living in an Australian Indigenous community. Population, social group sizes and rates of contact were estimated from structured observations along walked transects. Simultaneously, GPS telemetry collars were used to track dogs' movements and to quantify the frequency of contacts between individual animals. We estimated that the community's dog population was 326 ± 52, with only 9.8 ± 2.5% confined to a house yard. Short-term activity ranges of dogs varied from 9.2 to 133.7 ha, with males ranging over significantly larger areas than females. Contacts between two or more dogs occurred frequently, with entire females and neutered males accumulating significantly more contacts than spayed females or entire males. This indicates that sex and reproductive status are potentially important to epidemiology, but the effect of these differential contact rates on disease transmission requires further investigation. The observed combination of unrestrained dogs and high contact rates suggest that contagious disease would likely spread rapidly through the population. Pro-active management of dog populations and targeted education programs could help reduce the risks associated with disease spread.