Domestic Dogs Canis Familiaris Research Articles

Geographic hot spots of dingo genetic ancestry in southeastern Australia despite hybridisation with domestic dogs

Hybridisation resulting from human-driven shifts in species ranges is a global conservation concern. In Australia, hybridisation between dingoes (Canis dingo) and domestic dogs (Canis familiaris) has been identified as an extinction threat to the dingo, and is thought to be particularly widespread in south-eastern Australia. Here, we investigated the extent of hybridisation between dingoes and dogs in a sample of 783 wild-caught canids from eastern New South Wales, using an established 23-microsatellite test. We then mapped the distribution of these samples and identified three areas that are geographic hotspots of high dingo genetic ancestry using geospatial analysis. Between 9 and 23% of the wild canids that we sampled were classified as only having or likely to have only dingo ancestry. Only 0.6% of the wild canids we sampled were classified as having no dingo ancestry. Introgression from domestic dogs into the southeastern dingo gene pool has been extensive, with 76–88% of sampled dingoes carrying some dog ancestry. Spatial analyses revealed several geographic hotspots of high dingo genetic ancestry within north-eastern New South Wales (NSW) where there was a higher than expected prevalence of dingoes with no domestic dog ancestry. A key finding of our study is the observation of several regions where dingoes were largely free of admixture from dogs. There is an ongoing need for evidence-based strategies to reduce human-driven hybridisation by identifying and maintaining natural barriers to reproduction or limiting opportunities for wild-domesticate hybridisation. Globally, legislators and land managers may need to consider less restrictive species definitions to conserve endangered or ecologically significant taxa.

Comparative Study of the Bush Dog (Speothos venaticus) Karyotype and Analysis of Satellite DNA Sequences and Their Chromosome Distribution in Six Species of Canidae

The bush dog (Speothos venaticus, 2n = 74) is a near threatened species taxonomically classified among South American canids. We revised the bush dog karyotype and performed a comparative sequence analysis of satellite and satellite-like DNAs in 6 canids: the bush dog, domestic dog (Canis familiaris, 2n = 78), grey wolf (C. lupus, 2n = 78), Chinese raccoon dog (Nyctereutes procyonoides procyonoides, 2n = 54+B), red fox (Vulpes vulpes, 2n = 34+B), and arctic fox (V. lagopus, 2n = 48-50) to specify the species position among Canidae. Using FISH with painting and BAC probes, we found that the distribution of canid evolutionarily conserved chromosome segments in the bush dog karyotype is similar to that of the domestic dog and grey wolf. The bush dog karyotype differs by 2 acrocentric chromosome pairs formed by tandem fusions of the canine (29;34) and (26;35) orthologues. An interstitial signal of the telomeric probe was observed in the (26;35) fusion site in the bush dog indicating a recent evolutionary origin of this rearrangement. Sequences and hybridisation patterns of satellite DNAs were compared, and a phylogenetic tree of the 6 canid species was constructed which confirmed the bush dog position close to the wolf-like canids, and apart from the raccoon dog and foxes.

Occupancy, detectability, and density of crab-eating fox (Cerdocyon thous) in two protected areas of restinga habitats in Brazil

Crab-eating foxes (Cerdocyon thous (Linnaeus, 1766)) are frequently recorded in lists of mammal communities. However, studies quantifying aspects of the ecology of the species are uncommon in the literature. Thus, we aimed to quantify the density, activity, habitat use, and potential threats of C. thous in two protected areas (PAs) in the State of Espírito Santo, Brazil. We used data derived from camera traps and sand plots to model occupancy, detectability, activity; we also used random encounter models (REMs) to model density and abundance. We also estimated the activity of the species. Density of C. thous was 0.82 individuals/km2with a total abundance of 119 individuals. We concluded that in the PAs studied, C. thous had bimodal, twilight–nocturnal activity patterns and was associated with water sources. Although the species in the area has a relatively high density compared with that from other areas in Brazil, it could be locally threatened by the highway that crosses the two PAs, promoting roadkill events, and by domestic dogs (Canis familiaris Linnaeus, 1758) recorded in these areas. Results presented herein can be a starting point to support future work in the region and to make predictions regarding the management and conservation of C. thous, a widely distributed species.

Global Expansion of the Australian Biting Louse Heterodoxus spiniger Facilitated by Human Transport of Dog (Canis familiaris), and Implications for Prehistoric Cultural Interaction in Australasia

ABSTRACT For over a century, it has been pondered how the biting louse Heterodoxus spiniger, which evolved on the agile wallaby (Macropus agilis) in Australia/New Guinea, came to be found on domestic dogs (Canis familiaris) throughout much of the world. Various theories suggest that ancient transport of Australian dingoes (Canis dingo), or recent transport of domestic dogs or macropods are responsible for its global distribution. In this paper, we utilise reported museum specimens, entomological surveys and veterinary data to define an updated distribution of this notable ectoparasite, and explore the evidence for transport of its hosts that may be responsible for its dispersal. In the simplest scenario, H. spiniger first transferred from wallaby to dog in prehistoric New Guinea, probably through humans using dogs to hunt wallabies. If the further spread of this species preceded the global connections brought by European colonisation, dogs of Austronesian maritime cultures were the most likely vectors for its further dispersals into Asia, but it probably only arrived in the Americas following European settlement. As ancient specimens are unlikely to be recovered due to poor preservation conditions, a genomic approach should be pursued in further investigation of this species’ history.

Physiological Indicators of Attachment in Domestic Dogs (Canis familiaris) and Their Owners in the Strange Situation Test.

Behaviorally, attachment is demonstrated when one individual maintains close proximity to another individual and shows distress upon separation. For 29 owner-dog dyads, we employed a modified Ainsworth’s Strange Situation Test (SST) to investigate whether both members would show a physiological reaction to separation. Dogs experienced a series of separation from and reuniting events with their owners and were introduced to a stranger. Before and after the SST, saliva samples were taken from each dyad to measure stress-related analytes: cortisol (CORT) and chromogranin A (CgA). Dogs exhibited attachment behaviors toward owners as evidenced by more time spent in close proximity, more contact initiated and less time spent near the door, compared to episodes with the stranger. Dogs that initiated more contact with their owners in re-uniting episodes had lower CgA than dogs that initiated less contact, but their owners had higher CgA levels. Also during re-uniting episodes, dogs and owners spent more time near each other when owner CgA levels were low, owner CORT levels were high, and the dog had owner-reported separation anxiety. During the episodes alone with the stranger, dogs with higher CORT spent more time with the stranger. Finally, dogs’ initial CgA levels were correlated with their owner’s initial CORT levels, and dog final CORT levels were correlated with their owners’ final CORT levels, suggesting some hormonal synchrony within the dyad. As all owner-dog dyads were assessed as securely attached, attachment style differences could not explain variation in hormonal or behavioral results. These results suggest that dogs may respond to owner hormonal state and/or behavior and demonstrate that individual differences in responses to a behavioral challenge reflect the stress physiology of both dogs and their owners.

Regulations fail to constrain dog space use in threatened species beach habitats

The management of domestic dogs (Canis familiaris) in natural areas is controversial and more effective policy and management is required. We examine the occurrence and space use by dogs on southern Australian sandy beaches in different dog-leashing zones. We observed the people and dogs, and compliance with regulations. GPS loggers determined the space use by dogs (n = 161). Existing dog-leashing zones had no influence on the space use by dogs, and this related to poor compliance with dog-leashing rules (69.7% of 188 dogs observed at “on-leash” beaches were “off-leash”). Dogs moved up to 33 km, at maximum speeds of up to 19 km h−1, during beach visits. Larger dogs occupied slightly more space. Overall, off-leash dogs were frequent regardless of prevailing dog-leashing regulations and these did not constrain the space use by dogs. Current regulations appear ineffective, and alternatives such as “no-dog” zones to replace “leash-only” zones warrant investigation.

Mesocarnivore presence and behavior on a barrier island during sea turtle nesting season

Red fox (Vulpes vulpes) management has been conducted on Masonboro Island Reserve, a component of the North Carolina National Estuarine Research Reserve, North Carolina, USA, since 2013 to reduce depredation on loggerhead sea turtle (Caretta caretta) and green sea turtle (Chelonia mydas) nests. Depredation rates have varied among years indicating either an influx of red fox onto the island post cull or other mesocarnivores preying on sea turtle nests. We investigated the presence of red fox and other mesocarnivores on Masonboro Island Reserve after a culling event in 2016 to characterize mesocarnivore behavior and interactions during the turtle nesting season. We systematically placed 17 Moultrie® panoramic 150 passive infrared cameras every 0.80 km along the base of the dunes on the shoreline of Masonboro Island Reserve during May–October 2016. Of 81,509 pictures taken by the cameras, we observed 2 red fox and 1 Virginia opossum (Didelphis virginianus). There was 1 documented mammalian depredation event on turtle nests in 2016 and the number of false crawls (where females return to the ocean without laying eggs) was lower than the previous 5 years. Given that we only recorded 3 pictures on 2 different nights of mesocarnivores, our results may indicate that the 2016 cull was successful. Mesocarnivores, especially red fox and raccoons (Procyon lotor), on the mainland may temporarily shift their home range during the onset of the turtle nesting season to procure food for their offspring. By early fall, most mammal offspring disperse and likely recolonize the island annually, suggesting management efforts to reduce mammalian predators should continue. Human and domestic dog (Canis familiaris) presence on the island is abundant and also may influence turtle nest success.

Do dholes kill tigers?

Do dholes kill tigers?

Do Red Foxes (Vulpes Vulpes) Increase the Detectability of Scent Marks by Selecting Highly Conspicuous Substrates

In mammals, especially those that are nocturnal or crepuscular, chemical marks usually play a significant role as environmental labels. Scent marks in mammals can have many functions, including territorial defense and communication signals in the mating season. Furthermore, animals can increase the detectability of marks by selecting highly conspicuous locations and substrates on which to mark, such as stones and sticks, on or around faeces, other animal carcasses, anthropogenic features, and plants. Human-carnivore interactions can result in a conflict where perceived damage to livelihoods occurs in socio-economically poor areas. In the Shigar Valley, Karakorum Range, Pakistan, subsistence mixed farming is the predominant land use and red foxes (Vulpes vulpes) are widely persecuted. Understanding the effects of human activity and habitat factors on fox behaviors in the region are lacking. We used line transect surveys aided by a domestic dog (Canis familiaris) to detect fox faeces locations and characterize fox den form 2015-16-17. We encountered 467 fox scats by dog assistance. We tested for associations between scent deposition, and environmental variables including vegetation and substrate type, distribution of livestock carcasses and dung, roads and agricultural land at micro-habitat. We found more fox scats on aromatic plants, shrubs, and on or near livestock feaces and carcasses. Fox scent marking site selection varied for forested and shrub areas relative to open grassland or barren ground and vegetation cover and tree density at the microhabitat scale. The findings suggest that foxes do not avoid human activity per se and anthropogenic benefits (road kill, livestock carrion, crop food sources) may outweigh the costs of persecution. Foxes may also provide ecosystem benefits via seed dispersal, carrion removal and regulation of prey populations.

The Canine Frustration Questionnaire-Development of a New Psychometric Tool for Measuring Frustration in Domestic Dogs (Canis familiaris).

Introduction: Psychometric tools have been developed for the assessment of behavioral and affective traits in non-human animals. Frustration can be defined as an emotional reaction experienced after a given expectation is violated. Frustration is a negative emotional state and whilst it probably plays a key role in certain behavior problems in dogs (e.g., aggressive behaviors), there appears to have been little attempt to scale this affective tendency. Therefore, the aim of the current study was to develop a tool to assess frustration tendencies in dogs.Materials and Methods: An online owner survey was developed. Items covered demographics, the training/behavioral history of the dog, and 33 frustration related items scored using a 5-point Likert scale. The questionnaire was disseminated via on-line channels over a 5-month period. Two thousand three hundred forty-eight respondents completed the questionnaire. Of these, 273 respondents completed it a second time 6 weeks later, and a separate 276 respondents completed it a second time 1 year later. Additionally, 92 paired responses were collected where two carers completed the questionnaire independently about the same dog. Intra- and inter-rater reliabilities were assessed prior to structuring the items using principal component analysis (PCA) with a Varimax rotation. Items were retained if they loaded > 0.4 on at least one of the components extracted using the Kaiser criterion.Results: Twenty-two items were deemed to be reliable enough to be used in the PCA and 21 items loaded on a biologically meaningful 5-principal component solution. There was a significant positive correlation between each principal component and the owners' general perception of their dogs' frustration tendencies, alongside other expected correlates.Conclusion: This is the first reliable psychometric tool for the assessment of frustration in dogs—the Canine Frustration Questionnaire (CFQ). Further validation with behavioral tests and physiological measures is ongoing.

Associations among behavioral inhibition and owner-rated attention, hyperactivity/impulsivity, and personality in the domestic dog (Canis familiaris).

In humans, behavioral disinhibition is associated with attention-deficit/hyperactivity disorder (ADHD). Limitations to rodent models of ADHD-like behaviors/symptoms may be augmented by complementary ones, such as the domestic dog. We examined associations between family dogs' (N = 29; of 14 breeds and 12 mongrels) performance on a self-developed touchscreen behavioral Go/No-Go paradigm and their owner-rated inattention and hyperactivity/impulsivity, accounting for relevant covariates. A greater proportion of commission errors was associated with greater hyperactivity/impulsivity. Regardless of accuracy, relative to dogs with no previous training, those with basic training had shorter response latencies. Also, regardless of accuracy, greater confidence and extraversion were associated with shorter latencies, and greater openness was associated with longer latencies. Shorter latency to commission errors was associated with greater inattention. Findings support the dog as a model of the association between behavioral disinhibition and ADHD-like behaviors/symptoms and are early evidence of convergent validity between the behavioral paradigm and the rating scale measure in dogs. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Domestic cats (Felis catus) discriminate their names from other words

Two of the most common nonhuman animals that interact with humans are domestic dogs (Canis familiaris) and cats (Felis catus). In contrast to dogs, the ability of domestic cats to communicate with humans has not been explored thoroughly. We used a habituation-dishabituation method to investigate whether domestic cats could discriminate human utterances, which consisted of cats’ own names, general nouns, and other cohabiting cats’ names. Cats from ordinary households and from a ‘cat café’ participated in the experiments. Among cats from ordinary households, cats habituated to the serial presentation of four different general nouns or four names of cohabiting cats showed a significant rebound in response to the subsequent presentation of their own names; these cats discriminated their own names from general nouns even when unfamiliar persons uttered them. These results indicate that cats are able to discriminate their own names from other words. There was no difference in discrimination of their own names from general nouns between cats from the cat café and household cats, but café cats did not discriminate their own names from other cohabiting cats’ names. We conclude that cats can discriminate the content of human utterances based on phonemic differences.

The cocktail party effect in the domestic dog (Canis familiaris).

Like humans, canine companions often find themselves in noisy environments, and are expected to respond to human speech despite potential distractors. Such environments pose particular problems for young children, who have limited linguistic knowledge. Here, we examined whether dogs show similar difficulties. We found that dogs prefer their name to a stress-matched foil in quiet conditions, despite hearing it spoken by a novel talker. They continued to prefer their name in the presence of multitalker human speech babble at signal-to-noise levels as low as 0dB, when their name was the same intensity as the foil. This surpasses the performance of 1-year-old infants, who fail to prefer their name to a foil at 0dB (Newman in Dev Psychol 41(2):352-362, 2005). Overall, we find better performance at name recognition in dogs that were trained to do tasks for humans, like service dogs, search-and-rescue dogs, and explosives detection dogs. These dogs were of several different breeds, and their tasks were widely different from one another. This suggests that their superior performance may be due to generally more training and better attention. In summary, these results demonstrate that dogs can recognize their name even in relatively difficult levels of multitalker babble, and that dogs who work with humans are especially adept at name recognition in comparison with companion dogs. Future studies will explore the effect of different types of background noise on word recognition in dogs.

Isotopic analysis of the Blick Mead dog: A proxy for the dietary reconstruction and mobility of Mesolithic British hunter-gatherers

A single domestic dog (Canis familiaris) tooth was recovered from the Mesolithic site of Blick Mead in the Stonehenge landscape. As no human remains were recovered from the site, the dog tooth provides a potential proxy for reconstructing human diet. Previous studies have shown that domestic dogs often have similar δ13C and δ15N values to their human companions. Incremental dentine carbon and nitrogen isotope analysis and bulk enamel carbon, oxygen and strontium isotope analysis were obtained from the tooth to produce a life-history profile of the dog's diet and mobility. The δ13C and δ15N values indicate that there was little variation in the dog's diet between c.2 and 6 months of age. δ15N values range between +7.9 to +8.7‰, (mean +8.5‰), whereas δ13C values range between −21.3 and −20.5‰, (mean −20.9‰). These data suggest that the dog was consuming predominantly terrestrial herbivorous protein, with the possible inclusion of freshwater fish. The enamel 87Sr/86Sr ratio of 0.70796 can only be obtained from a chalk landscape, such as is found at Blick Mead and elsewhere in southern and southeastern Britain, or basalt terrains which are rare in southern Britain. The enamel δ18O(SMOW) value of 25.7‰ is not consistent with the dog residing at Blick Mead but appropriate contemporaneous data from dogs is currently lacking. The results are thus consistent with the dog originating in a chalk or possibly basaltic terrain elsewhere in Britain and Ireland or that the dog resided locally at a time when the climate was colder than present.

Unique genetic features of canine adenovirus type 1 (CAdV-1) infecting red foxes (Vulpes vulpes) in northern Norway and arctic foxes (Vulpes lagopus) in Svalbard.

Canine adenovirus type 1 (CAdV-1) is the aetiological agent of infectious canine hepatitis (ICH) in domestic dogs (Canis familiaris). In spite of the widespread use of vaccination, CAdV-1 continues to circulate in the dog population. Although a high number of serological screenings have indicated that CAdV-1 is widespread in fox species, little is known about the potential role of foxes as reservoirs of CAdV-1. Furthermore, very little data exist on the molecular features of this virus in foxes. To add to existing knowledge on CAdV-1 circulating in wild carnivores, tissue samples from CAdV-seropositive red foxes (Vulpes vulpes, n = 10) from the northern mainland of Norway and arctic foxes (Vulpes lagopus, n = 10) from the Svalbard archipelago, Norway, were investigated using a molecular approach to detect CAdV-1 DNA and important structural and non-structural genes of the detected viruses were sequenced and analysed. Amplicons characteristic for CAdV-1 were amplified from 14 out of 20 foxes (7 red foxes and 7 arctic foxes) and spleen and lymph node tissues resulted optimal targets for the viral DNA detection. The nucleotide sequences showed unique features that distinguished the viruses detected in this study from the CAdV-1 to date identified in wild carnivores and dogs. Greater attention should be given to genetically different CAdV-1 circulating in wild carnivores that may be transferred to dogs, potentially causing disease and reducing the effectiveness of available vaccines.

Activin promotes growth and antral cavity expansion in the dog ovarian follicle

Understanding regulators of folliculogenesis remains limited in the domestic dog (Canis familiaris), which challenges our ability to develop in vitro follicle culture systems for canid genome rescue efforts. Here, we investigated the influence of activin on dog follicle development and survival, oocyte quality, and FSH receptor expression in culture. Preantral (150 - ≤230 μm diameter), early antral (231 - ≤330 μm), and antral (>330–550 μm) stage follicles were encapsulated in a fibrin-alginate hydrogel with 0, 100, or 200 ng/ml rhActivin plus 0, 0.1, 1, or 10 μg/ml FSH for 12 or 21 d of in vitro culture. All follicle groups increased in diameter (P < 0.05) with activin acting synergistically with FSH to improve (P < 0.05) growth and antral cavity expansion (to >630 μm) in early antral and antral cohorts. This complementary effect was not linked to changes in FSHR mRNA expression (P > 0.05). Although not influencing (P > 0.05) follicle survival or transzonal projection (TZP) density in shorter term 12 d culture, activin in the presence of 1 ng/ml FSH maintained TZP density from the 12–21 d interval. Activin also increased oocyte diameter and improved nuclear integrity compared to un-supplemented controls. These results indicate that activin acts synergistically with FSH to promote growth and antral cavity expansion of the dog follicle in vitro, information useful to formulating an effective culture microenvironment for this species.

The dog (Canis familiaris) as a translational model of autism: It is high time we move from promise to reality.

Selecting appropriate animal models for a particular human phenomenon is a difficult but important challenge. The difficulty lies in finding animal behaviors that are not only sufficiently relevant and analog to the complex human symptoms (face validity) but also have similar underlying biological and etiological mechanisms (translational or construct validity), and have "human-like" responses to treatment (predictive validity). Over the past several years, the domestic dog (Canis familiaris) has become increasingly proposed as a model for comparative and translational neuroscience. In parallel to the recent advances in canine behavior research, dogs have also been proposed as a model of many human neuropsychiatric conditions, including autism spectrum disorder (ASD). In this opinion paper we will shortly discuss the challenging nature of autism research then summarize the different neurocognitive frameworks for ASD making the case for a canine model of autism. The translational value of a dog model stems from the recognition that (a) there is a large inter-individual variability in the manifestation of dogs' social cognitive abilities including both high and low phenotypic extremes; (b) the phenotypic similarity between the dog and human symptoms are much higher than between the rodent and human symptoms; (c) the symptoms are functionally analogous to the human condition; and (d) more likely to have similar etiology. This article is categorized under: Psychology > Comparative Psychology Cognitive Biology > Evolutionary Roots of Cognition.

Male and female anatomical homologies in the perineum of the dog (Canis familiaris).

Understanding the homologies between male and female perineal structure helps both evolutionary biologists and clinicians better understand the evolution and anatomy of canines. Domestic dogs (Canis familiaris) play an important role in human society, and canine perineal anatomy is important for maintaining dogs’ reproductive health for successful breeding and a wide variety of pathologies. Here, we investigate homologies between male and female perineal structure, identifying structures based on common function, anatomical relationships and attachments. In this investigation we dissected 21 male and female large‐breed dogs. We find broad structural homologies between male and female dogs related to erection, micturition and defecation, including muscles, fasciae and erectile tissue. Using these homologies will help anatomists and clinicians interpret the anatomical organization of the perineum, a notoriously difficult area of anatomy.

THE BIRCH CREEK CANIDS AND DOGS AS TRANSPORT LABOR IN THE INTERMOUNTAIN WEST

Historically, domestic dogs(Canis familiaris)have been documented as central features of Intermountain West and Great Plains Native American camps. Some of these dogs were bred specifically for largeness and stamina to haultravoisand to carry pannier-style packs. Ethnographic accounts frequently highlight the importance of dogs in moving through the Intermountain West and the plains, reporting loads as heavy as 45 kg (100 lbs). We calculated body mass from skeletal morphometric data and used these to estimate prehistoric and historic dog load capacities for travois and pannier-style packs in the Intermountain West, Great Plains, and Great Basin. Specimens of large dogs recovered from sites in the Birch Creek Valley in Idaho and on the Great Plains indicate the animals could carry weights comparable to ethnographically recorded loads. Further, direct dating of the Birch Creek dog specimens indicated that dogs of this size have been present in the Intermountain West for more than 3,000 years. These data have important implications for our understanding of prehistoric mobility in the Intermountain West and the plains and suggest that the use of dogs in transporting cargo may have begun as early as 5,000 years ago.

Oxytocin modulates responses to inequity in dogs

Although several animals respond negatively to inequity, the underlying neurochemistry of the process remains poorly understood. In this study, we tested whether the neuropeptide oxytocin mediates responses to inequitable outcomes in domestic dogs (Canis familiaris). Subjects exchanged tokens to receive a food reward in conditions in which the distribution of reward varied. Dogs did respond negatively to inequity, refusing to participate in the test when their partner was rewarded and they were not. Their responses could not be explained merely by frustration, since the presence of a partner being rewarded had a significant effect on their behavior, compared to when the partner was present but not rewarded. Furthermore, after oxytocin intake dogs were less sensitive to the inequitable distribution of reward, performing more successful trials than when administered with placebo. Further, oxytocin treatment also increased dogs' attention towards their partners, and slowed their decision times, but did not affect their affiliation level towards their partners or the experimenter. Together, our findings suggest that oxytocin modulates responses to inequity in dogs by potentially affecting decision-making processes, but not by increasing affiliation.