Search Results (59)

Most research on domestic dog (Canis familiaris) behavior has focused on pets with restricted movement. However, free-ranging dogs exist in diverse cultural contexts globally, and their interactions with humans are less understood. Tourists can facilitate unrestricted dog movement into wilderness areas, where they may negatively impact wildlife. This study investigated which stimuli—namely, voice, touch, or food—along with inherent factors (age, sex, sociability) motivate free-ranging dogs to follow a human stranger. We measured the distance (up to 600 m) of 129 free-ranging owned and stray dogs from three villages in southern Chile as they followed an experimenter who presented them one of the above stimuli or none (control). To evaluate the effect of dog sociability (i.e., positive versus stress-related or passive behaviors), we performed a 30 s socialization test (standing near the dog without interacting) before presenting a 10 s stimulus twice. We also tracked whether the dog was in the company of other dogs. Each focus dog was video-recorded and tested up to three times over five days. Generalized linear mixed-effects models revealed that the food stimulus significantly influenced dogs’ motivation to follow a stranger, as well as a high proportion of sociable behaviors directed towards humans and the company of other dogs present during the experiment. Juveniles tended to follow a stranger more than adults or seniors, but no effects were found for the dog’s sex, whether an owner was present, the repetition of trials, the location where the study was performed, or for individuals as a random variable. This research highlights that sociability as an inherent factor shapes dog–stranger interactions in free-ranging dogs when food is given. In the context of wildlife conservation, we recommend that managers promote awareness among local communities and tourists to avoid feeding dogs, especially in the context of outdoor activities close to wilderness. Full article

The domestication of the dog (Canis lupus familiaris) is one of the oldest and most complex processes of interaction between humans and animals. This phenomenon may have begun sometime between 30 and 15 ky calBP. Archaeological and genetic studies have provided valuable insights into dog domestication, although the precise geographic location and origin of this process remain controversial and under debate. New methodologies, such as taphonomic analyses, offer opportunities to deepen our understanding of past human–dog interactions. In this context, the present study examines tooth marks found on some bone remains from the Upper Magdalenian site (15,500–13,200 cal BP) of Coímbre Cave (Peñamellera Alta, Asturias, Spain). The low incidence of carnivores at the site has raised the possibility that the tooth marks may have been produced by canids. However, a detailed taphonomic analysis combining geometric morphometrics with robust statistical methods—including MANOVA with post-hoc permutation tests—revealed that the marks identified at the site do not significantly differ from tooth marks produced by humans (p = 0.086). In contrast, tooth marks produced by other carnivores, such as Canis lupus signatus and Canis lupus familiaris, showed significant differences (p < 0.003). Although our study could not confirm the presence of domesticated dogs at the Magdalenian levels of Coímbre Cave, it has documented taphonomic processes that are rarely identified in the archaeological record. Furthermore, this study highlights the potential of tooth mark analysis as a key tool for future research on human–animal interactions in archaeological contexts. Full article

Rabies virus (RABV; species Lyssavirus rabies) causes rabies, a disease of the central nervous system that invariably results in the death of the host. In South Africa, studies have indicated that RABV is maintained by animal species that include four wildlife carnivore species—the black-backed jackal (Canis mesomelas), bat-eared fox (Otocyon megalotis), yellow mongoose (Cynictis penicillata), and aardwolf (Proteles cristatus)—and domestic dogs (Canis lupus familiaris). The complex natural ecology holds significant implications for the control and elimination of rabies. In this study, confirmed animal rabies case data, including geospatial features, were analyzed for 12,879 laboratory-confirmed animal cases reported on a database managed by the Department of Agriculture, Land Reform and Rural Development (DALRRD). Sequence data generated from animal rabies cases in South Africa were also analyzed, which included 1374 cytoplasmic domain of the glycoprotein and the G-L intergenic sequences using maximum likelihood (ML) and Bayesian inference. The analysis provides insights into the transmission dynamics involving several wildlife species and domestic dogs in South Africa. This information is crucial for the strategic planning for rabies control and elimination programs, and particularly in understanding the interlinked nature of some lineages and the importance of the cross-border spread of rabies. This analysis provided an improved understanding of the distribution of the RABV lineages in South Africa and identified areas that can be targeted for rabies control strategies to limit future spread of RABV, which is important due to the limited available resources that must be carefully managed to allow optimal control. Full article

The domestic dog (Canis lupus familiaris) is a competent host for Mycobacterium (M.) bovis infection but no ante mortem diagnostic tests have been fully validated for this species. The aim of this study was to compare the performance of ante mortem diagnostic tests across samples collected from dogs considered to be at a high or low risk of sub-clinical M. bovis infection. We previously tested a total of 164 dogs at a high risk of infection and here test 42 dogs at a low risk of infection and 77 presumed uninfected dogs with a combination of cell-based and/or serological diagnostic assays previously described for use in non-canid species. The interferon-gamma release assay (IGRA) using peripheral blood mononuclear cells (PBMCs) identified the highest number of test-positive animals (85, 52%), with a suggested specificity of 97.3%, whilst a whole-blood IGRA was found to be unreliable. The production of antigen-specific tumour necrosis factor-alpha (TNF-α) by PBMC in response to a cocktail of ESAT-6 and CFP-10 peptides correlated very strongly with the overall IGRA results, suggesting future diagnostic potential. All three serological assays employed in this study (Idexx M. bovis Ab ELISA, [Idexx Laboratories, Westbrook, ME, USA], DPP VetTB lateral flow assay [Chembio, Medford, NY, USA], and comparative PPD ELISA [in-house]) identified seropositive dogs but, overall, the test-positive rate for the serological assays was only one third that of the cellular-based assays. Circulating serum cytokine concentrations of interferon gamma and TNF-α were not statistically different between the high- and low-risk groups of dogs. While many dogs in the high-risk group had serum biochemical abnormalities, these did not correlate with the findings from the diagnostic TB tests. This study demonstrates, for the first time, the utility of two cellular and three serological assays for detecting sub-clinical M. bovis infections of dogs. Whilst the data suggest a high test specificity for all assays evaluated, further work is needed to validate the sensitivity and specificity of individual or combinations of tests using sufficient numbers of dogs of a known infection status. Full article

Cryptosporidium spp. and Giardia duodenalis are zoonotic food- and water-borne protozoa of veterinary importance. They are one of the main causes of diarrhea in domestic dogs (Canis familiaris). Wild canids, such as red foxes (Vulpes vulpes) and raccoon dogs (Nyctereutes procyonoides), can act as natural reservoirs for these parasites. The aim of this study was to estimate the prevalence of these pathogens and analyze possible factors that may affect the infection in wild and domestic canids. A total of 373 domestic dog, 219 red fox, and 78 raccoon dog fecal samples were collected and tested for Cryptosporidium spp. and G. duodenalis presence with direct immunofluorescent staining. The dog owners filled a questionnaire on the dog’s habits and lifestyle to identify and analyze potential factors that may affect the occurrence of these parasites in dogs. Cryptosporidium spp. were found in 16.3%, 28.3%, and 28.2% and G. duodenalis in 0.7%, 27.4%, and 30.8% of the examined dogs, red foxes, and raccoon dogs, respectively. The highest prevalence was observed in puppies—15.4% and 18.5% for Cryptosporidium spp. and G. duodenalis, respectively. In all three canid species, infection with Cryptosporidium increases the risk of co-infection with Giardia and vice versa. Full article

Spatial navigation allows animals to understand their environment position and is crucial to survival. An animal’s primary mode of spatial navigation (horizontal or vertical) is dependent on how they naturally move in space. Observations of the domestic dog (Canis familiaris) have shown that they, like other terrestrial animals, navigate poorly in vertical space. This deficit is visible in their use of multi-story buildings. To date, no research has been conducted to determine if dogs can learn how to navigate in an anthropogenic vertical environment with the help of a landmark. As such, we herein investigate the effect of the addition of a visual or olfactory landmark on dogs’ ability to identify when they are on their home floor. Subject behaviors toward their home door and a contrasting floor door were compared before and after exposure to a landmark outside of their home door. While subjects initially showed no difference in latency to approach an apartment door on their home or a wrong floor, we found a significant difference in latency to approach the doors in the test trials for subjects who approached the doors in every trial. Other findings are equivocal, but this result is consistent with the hypothesis that dogs can learn to navigate in vertical space. Full article

Studies are being conducted on the anatomical structures of various wild animals. Despite the ecological importance of the Korean raccoon dog (Nyctereutes procyonoides koreensis), limited research has been conducted on its anatomical structure. This study is the first to establish a reference range for joint orientation angles in the limbs of the Korean raccoon dog. Joint orientation angles are an unexplored concept not only in Korean raccoon dogs but also in other wildlife. However, they are important in the examination of the skeletal anatomy of humans and companion animals, such as dogs and cats. Because this type of measurement is still emerging in wildlife research, we applied the methodology used in the domestic dog (Canis lupus familiaris). Angles were measured between the mechanical or anatomical axis and the joint orientation lines in the thoracic and pelvic limbs of Korean raccoon dogs. No significant differences were observed between the sexes or between the left and right sides. These findings are consistent with those observed in domestic dogs. Based on this study, a reference range of joint orientation angles could be established for Korean raccoon dogs. Full article

Anaplasmataceae bacteria are emerging infectious agents transmitted by ticks. The aim of this study was to identify the molecular diversity of this bacterial family in ticks and hosts, both domestic and wild, as well as blood meal sources of free-living ticks in northeastern Paraguay. The bacteria were identified using PCR-HRM, a method optimized for this purpose, while the identification of ticks and their blood meal was performed using conventional PCR. All amplified products were subsequently sequenced. The bacteria detected in the blood hosts included Ehrlichia canis, Anaplasma platys, and Anaplasma phagocytophilum, Candidatus Anaplasma boleense, and Wolbachia spp., which had not been previously reported in the country. Free-living and parasitic ticks on dogs (Canis lupus familiaris) and wild armadillos (Dasypus novemcinctus) were collected and identified as Rhipicephalus sanguineus and Amblyomma spp. The species E. canis, A. platys, A. phagocytophilum, and Ca. A. boleense were detected in domestic dog ticks, and E. canis and A. platys were found for the first time in armadillos and free-living ticks. Blood feeding sources detected in free-living ticks were rodents, humans, armadillos and dogs. Results show a high diversity of tick-borne pathogens circulating among domestic and wild animals in the northeastern region of Paraguay. Full article

Assessing the behaviour and physical attributes of domesticated dogs is critical for predicting the suitability of animals for companionship or specific roles such as hunting, military or service. Common methods of behavioural assessment can be time consuming, labour-intensive, and subject to bias, making large-scale and rapid implementation challenging. Objective, practical and time effective behaviour measures may be facilitated by remote and automated devices such as accelerometers. This study, therefore, aimed to validate the ActiGraph^® accelerometer as a tool for behavioural classification. This study used a machine learning method that identified nine dog behaviours with an overall accuracy of 74% (range for each behaviour was 54 to 93%). In addition, overall body dynamic acceleration was found to be correlated with the amount of time spent exhibiting active behaviours (barking, locomotion, scratching, sniffing, and standing; R² = 0.91, p < 0.001). Machine learning was an effective method to build a model to classify behaviours such as barking, defecating, drinking, eating, locomotion, resting-asleep, resting-alert, sniffing, and standing with high overall accuracy whilst maintaining a large behavioural repertoire. Full article

Visceral leishmaniasis is a disease caused by protozoa of the species Leishmania (Leishmania) infantum (syn = Leishmania chagasi) and Leishmania (Leishmania) donovani, which are transmitted by hematophagous insects of the genera Lutzomyia and Phlebotomus. The domestic dog (Canis familiaris) is considered the main urban reservoir of the parasite due to the high parasite load on its skin, serving as a source of infection for sandfly vectors and, consequently, perpetuating the disease in the urban environment. Some factors are considered important in the perpetuation and spread of canine visceral leishmaniasis (CVL) in urban areas, such as stray dogs, with their errant behavior, and houses that have backyards with trees, shade, and organic materials, creating an attractive environment for sandfly vectors. CVL is found in approximately 50 countries, with the number of infected dogs reaching millions. However, due to the difficulty of controlling and diagnosing the disease, the number of infected animals could be even greater. In the four continents endemic for CVL, there are reports of disease expansion in endemic countries such as Brazil, Italy, Morocco, and Tunisia, as well as in areas where CVL is not endemic, for example, Uruguay. Socio-environmental factors, such as migration, drought, deforestation, and global warming, have been pointed out as reasons for the expansion into areas where it had been absent. Thus, the objective of this review is to address (i) the distribution of CVL in endemic areas, (ii) the role of the dog in the visceral leishmaniasis epidemiology and the factors that influence dog infection and the spread of the disease, and (iii) the challenges faced in the control of CVL. Full article

It has been argued that the increase in the consumption of dogs in the southern Levant during the Iron Age was due to the advent of the Philistines/“Sea Peoples” into the region. In this study, we test this proposal through the presentation of new information on dog consumption and its depositional context in Bronze and Iron Age strata from the archaeological site of Tell Zirāʿa (Jordan), and we compare the results to other sites in the region. Our study does not support that such behaviour is a signal of ethnic identity. Full article

The evolution of facial muscles in dogs has been linked to human preferential selection of dogs whose faces appear to communicate information and emotion. Dogs who convey, especially with their eyes, a sense of perceived helplessness can elicit a caregiving response from humans. However, the facial muscles used to generate such expressions may not be uniquely present in all dogs, but rather specifically cultivated among various taxa and individuals. In a preliminary, qualitative gross anatomical evaluation of 10 canid specimens of various species, we find that the presence of two facial muscles previously implicated in human-directed canine communication, the levator anguli occuli medialis (LAOM) and the retractor anguli occuli lateralis (RAOL), was not unique to domesticated dogs (Canis familiaris). Our results suggest that these aspects of facial musculature do not necessarily reflect selection via human domestication and breeding. In addition to quantitatively evaluating more and other members of the Canidae family, future directions should include analyses of the impact of superficial facial features on canine communication and interspecies communication between dogs and humans. Full article

Reverse zoonotic transmission events of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been described since the start of the pandemic, and the World Organisation for Animal Health (WOAH) designated the detection of SARS-CoV-2 in animals a reportable disease. Eighteen domestic and zoo animals in Great Britain and Jersey were tested by APHA for SARS-CoV-2 during 2020–2023. One domestic cat (Felis catus), three domestic dogs (Canis lupus familiaris), and three Amur tigers (Panthera tigris altaica) from a zoo were confirmed positive during 2020–2021 and reported to the WOAH. All seven positive animals were linked with known SARS-CoV-2 positive human contacts. Characterisation of the SARS-CoV-2 variants by genome sequencing indicated that the cat was infected with an early SARS-CoV-2 lineage. The three dogs and three tigers were infected with the SARS-CoV-2 Delta variant of concern (B.1.617.2). The role of non-human species in the onward transmission and emergence of new variants of SARS-CoV-2 remain poorly defined. Continued surveillance of SARS-CoV-2 in relevant domestic and captive animal species with high levels of human contact is important to monitor transmission at the human−animal interface and to assess their role as potential animal reservoirs. Full article

Leishmania infantum is a hemopathogen of importance for the health of domestic dogs (Canis lupus familiaris), causing canine leishmaniasis (CanL), and it is also the etiological agent of human visceral leishmaniasis (HVL). This parasite was not reported in southern Brazil until the early 2000s, but CanL and HVL were increasingly reported in the last 15 years, mainly in cities bordering Argentina. The present study aimed to detect L. infantum in domestic dogs and to determine the main clinical manifestations in infected animals from Uruguaiana, a city with a high incidence of CanL. Fifty-one dogs suspected of having CanL in the urban perimeter of the city were clinically examined by veterinarians and investigated for the occurrence of L. infantum with two immunoassays (rapid chromatography test and ELISA) and real-time PCR (polymerase chain reaction). Clinical signs were compared in positive and negative L. infantum animals. A total of 31 dogs (60.8%) were infected with L. infantum. The main clinical manifestations associated with CanL dogs were onychogryphosis and peeling (p < 0.05). L. infantum was frequently detected in urban dogs from Uruguaiana, highlighting the concerning situation regarding health in this city. The occurrence of some clinical signs (onychogryphosis/peeling) could help to detect CanL more frequently in the canine population. Full article

Livestock predation induces global human–wildlife conflict, triggering the retaliatory killing of large carnivores. Although domestic dogs (Canis familiaris) contribute to livestock depredation, blame primarily falls on wild predators. Dogs can also transmit pathogens between wildlife, domestic animals, and humans. Therefore, the presence of free-ranging dogs can have negative consequences for biodiversity conservation, smallholder economy, food supply, and public health, four of the United Nations’ Sustainable Developed Goals (SDGs) for 2030. In Ecuador, where livestock sustains rural households, retaliatory poaching threatens Andean bear (Tremarctos ornatus), jaguar (Panthera onca), and puma (Puma concolor) populations. However, the role of dogs in these incidents remains underexplored. The present study evaluates the possibility of reliable molecular identification of predatory species from DNA traces in bite wounds. Our results revealed the presence of dog saliva on four out of six livestock carcasses presumably attacked by wild predators. These findings highlight the importance of rectifying misinformation about large carnivores in Ecuador and the need to control dog populations. We recommend that local administrations incorporate DNA analysis into livestock predation events to examine how common the problem is, and to use the analysis to develop conflict mitigation strategies which are essential for the conservation of large carnivores. Full article