Wild Canid Species Research Articles

High-resolution computed tomographic (HRCT) image series from 413 canid and 18 felid skulls

Computed tomography (CT) is a non-invasive, three-dimensional imaging tool used in medical imaging, forensic science, industry and engineering, anthropology, and archaeology. The current study used high-resolution medical CT scanning of 431 animal skulls, including 399 dog skulls from 152 breeds, 14 cat skulls from 9 breeds, 14 skulls from 8 wild canid species (gray wolf, golden jackal, coyote, maned wolf, bush dog, red fox, Fennec fox, bat-eared fox), and 4 skulls from 4 wild felid species (wildcat, leopard, serval, caracal). This comprehensive and unique collection of CT image series of skulls can provide a solid foundation not only for comparative anatomical and evolutionary studies but also for the advancement of veterinary education, virtual surgery planning, and the facilitation of training in sophisticated machine learning methodologies.

Phylogenetic inferences based on distinct molecular markers reveals a novel Babesia (Babesia pantanalensis nov. sp.) and a Hepatozoon americanum-related genotype in crab-eating foxes (Cerdocyon thous)

Piroplasmids and Hepatozoon spp. Are apicomplexan protozoa that may cause disease in several canid species. The present study aimed to expand the knowledge on the diversity of piroplasmids and Hepatozoon in crab-eating foxes (Cerdocyon thous; n = 12) sampled in the Pantanal of Mato Grosso do Sul State, central-western Brazil. PCR assays based on the 18S rRNA were used as screening. Three (25%) and 11 (91.7%) were positive for piroplasmids and Hepatozoon spp., respectively. Co-infection was found in three C. thous. Phylogenetic analyses based on the near-complete 18S rRNA, cox-1 and hsp70 genes evidenced the occurrence of a novel of Babesia spp. (namely Babesia pantanalensis nov. sp.) closely related to Rangelia vitalii and Babesia sp. ‘Coco’. This finding was supported by the genetic divergence analysis which showed (i) high divergence, ranging from 4.17 to 5.62% for 18 S rRNA, 6.16% for hps70 and 4.91–9.25% for cox-1 and (ii) the genotype network (which displayed sequences separated from the previously described Piroplasmida species by median vectors and several mutational events). Also, phylogenetic analysis based on the 18S rRNA gene of Hepatozoon spp. positioned the sequences obtained herein in a clade phylogenetically related to Hepatozoon sp. ‘Curupira 2’, Hepatozoon sp. detected in domestic and wild canids from Uruguay and Hepatozoon americanum. The present study described Babesia pantanalensis nov sp. and Hepatozoon closely related to H. americanum in crab-eating foxes from Brazil. Moreover, the coinfection by piroplasmids and Hepatozoon sp. for the first time in crab-eating foxes strongly suggesting that this wild canid species potentially acts as a bio-accumulate of hemoprotozoan in wild environment.

Adaptations to sociality in the mimetic and auricular musculature of the African wild dog (Lycaon pictus).

The African wild dog (Lycaon pictus) is a highly social canid that engages in sophisticated, coordinated group hunting tactics to procure large game. It is one of the most effective hunters of the African savannah, due to its highly developed communication methods. It also has large, mobile ears which enhance its auditory capabilities while hunting and assist with thermoregulation. Recent research suggested that certain muscles of facial expression, particularly those involved with expressive eyebrow movement, evolved solely in domestic dogs (Canis familiaris) to facilitate communication with their human owners. However, it is unclear whether highly social wild canid species may also employ similar expressive eye communication. We performed detailed dissections of an adult male L. pictus to evaluate and describe its mimetic and auricular musculature. Overall, L. pictus has well-developed facial and ear muscles. Musculi levator anguli oculi medialis (LAOM) and retractor anguli oculi lateralis (RAOL), mimetic muscles of hypothesized importance in domestic dog-human non-verbal communication, are enlarged in L. pictus, comparable in size to those of domestic dogs, as is m. orbicularis oculi. This morphology suggests that ocular facial expressions contribute to within-pack communication in wild dogs and are not unique to domestic dogs. The auricular muscles of L. pictus are well-developed, supporting greater leverage and fine manipulation of its large, mobile ears. These muscular adaptations facilitate the highly social ecology of African wild dogs and challenge current interpretations about the unique nature of domestic dog facial expressions.

Binding Affinity, Selectivity, and Pharmacokinetics of the Oxytocin Receptor Antagonist L-368,899 in the Coyote (Canis latrans).

L-368,899 is a selective small-molecule oxytocin receptor (OXTR) antagonist originally developed in the 1990s to prevent preterm labor. Although its utility for that purpose was limited, L-368,899 is now one of the most commonly used drugs in animal research for the selective blockade of neural OXTR after peripheral delivery. A growing number of rodent and primate studies have used L-368,899 to evaluate whether certain behaviors are oxytocin dependent. These studies have improved our understanding of oxytocin's function in the brains of rodents and monkeys, but very little work has been done in other mammals, and only a single paper in macaques has provided any evidence that L-368,899 can be detected in the CNS after peripheral delivery. The current study sought to extend those findings in a novel species: coyotes ( Canis latrans ). Coyotes are ubiquitous North American canids that form long-term monogamous pair-bonds. Although monogamy is rare in rodents and primates, all wild canid species studied to date exhibit social monogamy. Coyotes are therefore an excellent model organism for the study of oxytocin and social bonds. Our goal was to determine whether L-368,899 is a viable candidate for future use in behavioral studies in coyotes. We used captive coyotes at the USDA National Wildlife Research Center's Predator Research Facility to evaluate the pharmacokinetics of L-368,899 in blood and CSF during a 90-min time course after intramuscular injection. We then characterized the binding affinity and selectivity of L-368,899 to coyote OXTR and the structurally similar vasopressin 1a receptor. We found that L-368,899 peaked in CSF at 15 to 30 min after intramuscular injection and slowly accumulated in blood. L-368,899 was 40 times more selective for OXTR than vasopressin 1a receptors and bound to the coyote OXTR with an affinity of 12 nM. These features of L-368,899 support its utility in future studies to probe the oxytocin system of coyotes.

Neglected zoonotic helminthiases in wild canids: new insights from South America.

The global threat of neglected tropical diseases (NTDs) constitutes a public health issue in underdeveloped countries. Zoonotic helminthiases are the most common human NTD agents in developing countries in sub-Saharan Africa, Asia, and the Americas, causing a global burden of disease that exceeds that of more recognized infectious diseases such as malaria and tuberculosis. Wild canids are well-known mammals that act as natural reservoirs of zoonotic-relevant helminthiasis worldwide, thus playing a pivotal role in their epidemiology and transmission to humans. Here we evaluate the occurrence of zoonotic gastrointestinal helminths in two Neotropical wild canid species from the Amazonian and Andean regions of Colombia, i.e., the bush dog (Speothos venaticus) and the crab-eating fox (Cerdocyon thous). We recovered tapeworm proglottids from bush dog fecal samples and identified them molecularly as the canine-specific lineage of Dipylidium caninum by using cytochrome c oxidase subunit I (cox1) gene sequences. Moreover, examination of a crab-eating fox during necropsy revealed the presence of non-embryonated eggs of the neglected nematode Lagochilascaris cf. minor, in addition to eggs and gravid proglottids of the cestode Spirometra mansoni. These findings represent the first report of zoonotic-relevant cestodes, i.e., D. caninum ("canine genotype"), S. mansoni, and the nematode L. cf. minor, in bush dogs and crab-eating foxes as final hosts. The occurrence of these zoonotic helminthiases in wild canid species calls for regular monitoring programs to better understand the epidemiology and transmission routes of neglected dipylidiasis, lagochilascariosis, and sparganosis in South America.

Can a traditional partner preference test quantify monogamous behavior in captive coyotes?

Social monogamy is a unique social system exhibited by only 3–5% of mammalian taxa; however, all wild canid species exhibit this social system. Despite the high prevalence of social monogamy among canids, little is known about how they form selective social attachment relationships among non-kin. Thus, we aimed to quantify monogamous behavior in a highly ubiquitous canid, the coyote (Canis latrans). We adapted the three-chambered partner preference test, which was originally developed for prairie voles (Microtus ochrogaster), to assess social preference in mated pairs of captive coyotes at the USDA Predator Research Facility. We quantified monogamy-related behaviors, such as time spent in spatial proximity to a pair-mate versus a stranger. Our behavioral ethogram also included visual seeking, olfactory investigations, ears down, scent marking, and affiliative behavior. Test subjects showed significantly greater affiliative behavior toward their partner than toward a stranger. However, there was extremely high variability both within and between coyote pairs across behavioral measures. These data suggest the need for larger sample sizes when working with species with high individual variability, as well as the need for species- and facility-specific modifications to this testing paradigm and/or ethogram to better adapt it from its laboratory and rodent-based origins.

Susceptibility of Wild Canids to SARS-CoV-2

We assessed 2 wild canid species, red foxes (Vulpes vulpes) and coyotes (Canis latrans), for susceptibility to SARS-CoV-2. After experimental inoculation, red foxes became infected and shed infectious virus. Conversely, experimentally challenged coyotes did not become infected; therefore, coyotes are unlikely to be competent hosts for SARS-CoV-2.

Chagas Immunochromatographic Rapid Test in the Serological Diagnosis of Trypanosoma cruzi Infection in Wild and Domestic Canids.

Canis lupus familiaris (domestic dog) represents a reliable sentinel for the occurrence of a well-established transmission cycle of Trypanosoma cruzi among wild mammals in the surroundings and, consequently, where the risk of human infection exists. Serological diagnosis is the chosen method to identify T. cruzi infection in dogs that, in Brazil, rarely present positive parasitological tests. The use of recombinant chimeric parasitic antigens results in a sensitive and specific serological diagnostic test in contrast to the use of crude T. cruzi antigens. Our objective was to evaluate the Chagas/Bio-Manguinhos Lateral Flow Immunochromatographic Rapid Test (Chagas-LFRT) for the diagnosis of T. cruzi infection in domestic dogs and the potential of application of this diagnostic platform to wild canid species. Two recombinant proteins (IBMP-8.1 and IBMP-8.4) that displayed the best performance in the enzyme immunoassay (ELISA) in previous studies were tested in a platform with two diagnostic bands. A panel of 281 dog serum samples was evaluated: 133 positive for T. cruzi by serological diagnosis, including 20 samples with positive blood cultures belonging to different discrete typing units (DTUs); 129 negative samples; and 19 samples from dogs infected by other trypanosomatids: Leishmania infantum, Trypanosoma rangeli, Trypanosoma caninum and Crithidia mellificae, in addition to samples infected by Anaplasma platys, Dirofilaria immitis and Erlichia sp. that were employed to evaluate eventual cross-reactions. We also evaluated the Chagas-LFRT to detect T. cruzi infection in 9 serum samples from six wild canid species. We observed that the intensity pattern of the bands was directly proportional to the serological titer observed in IFAT. The sensitivity was 94%, the specificity was 91% according to the ROC curve, and the defined cutoff was an optical density of 4.8. The agreement obtained was considered substantial by the kappa analysis (84%). From T. cruzi positive hemoculture samples, 88.9% were positive by Chagas-LFRT. The test was efficient in recognizing infections by five of the six T. cruzi DTUs. Cross-reactions were not observed in infections by L. infantum, T. rangeli, T. caninum and D. immitis; however, they were observed in sera of dogs infected by Crithidia mellificae, Anaplasma sp. and Erlichia sp. A strong reaction was observed when serum samples from wild canids were submitted to the Protein A affinity test, confirming its applicability for these species. This test will allow rapid preventive actions in areas with high risk to the emergence of Chagas disease in a safer, reliable, low-cost and immediate manner, without the need for more complex laboratory tests.

Canids (Caninae) from the Past of Venezuela

There are three extant species of wild canids in Venezuela: Urocyon cinereoargenteus, Cerdocyon thous, and Speothos venaticus, excluding the feral domestic dog (Canis familiaris). However, a review of paleontological material that was published previously, along with newly reported ancient specimens, reveals a distinct historical diversity for the same region. The gray fox, U. cinereoargenteus, is the only small-sized taxon and the only Vulpini (true fox) identified to date in the fossil record of Venezuela; its presence is limited to the late Pleistocene of the Mene de Inciarte site, Zulia State. In contrast, large canids are more abundant. Aenocyon dirus (subtribe Canina), the dire wolf from the late Pleistocene, was reported from the sites El Mene de Inciarte, Muaco in Falcón State, and for the first time in El Breal de Orocual (ORS20) in Monagas State. The genus Protocyon, a native South American canid (subtribe Cerdocyonina), is recognized in the country from late Pleistocene Inciarte (Protocyon troglodytes sensu lato), and late Pliocene–early Pleistocene Orocual (ORS16) (Protocyon orocualensis sp. nov.). Finally, we report a possible genus Theriodictis from the late Pleistocene Orocual; this is a Cerdocyonina not previously mentioned for the northern region of South America. These records present broader diversity and suggest a more complex evolutionary history than previously thought for South American canids.

Occurrence of Echinococcus spp. in red foxes and wolves in the protected area of the Tatra National Park in southern Poland - a threat to human health.

Echinococcus multilocularis has been endemic in red foxes in eastern and central parts of Europe, and E.granulosus s. l. identified in wolves in some countries. In recent years, wolves hale emerged as potentially important definitive hosts of E. multilocularis. This aim of the survey was to record indirectly using nested-PCR test with faecal samples the presence of Echinococcus multilocularis and E. granulosus s. l. in the two species of wild canids in the protected area of the Tatra National Park (TNP) in Western Carpathian, southern mountainous part of Poland. From February to June 2019, experienced staff of TNP randomly collected fox and wolf faeces on and off hiking trails at altitudes from 850 m to 2,000 m above sea level. In total, 91 faecal samples from red foxes and 19 from wolves were collected. Genomic DNA was obtained by direct extraction from faecal samples using a commercial kit, and from taeniid eggs retrieved from the same samples after flotation. A nested PCR screening of 91 red fox faeces indicated the prevalence of E. multilocularis of 4.4%. Positive samples were confirmed by sequencing parts of the mitochondrial cytochrome c oxidase subunit 1 gene (cox1). Neither genomic DNA of E. multilocularis nor of E. granulosus s.l. was obtained from 19 wolves faeces, nor from taeniid eggs retrieved from these samples by initial flotation. The current results show that humans might be exposed to a risk of fox tapeworm infection in nature, even at high altitude inan alpine zone, in an environment contaminated by roaming red foxes encouraged by food leftovers on mountain trails.

Serosurvey of antibodies against zoonotic pathogens in free-ranging wild canids (Cerdocyon thous and Lycalopex gymnocercus) from Southern Brazil

The expansion of urbanization on natural areas is increasing contact between human populations with wild animals. Wild carnivores can act as sentinel hosts or environmental health indicators. Thus, the aim of this work was to investigate the exposure of two major species of wild canids from Southern Brazil to selected pathogens. For that, we live-trapped free-ranging Cerdocyon thous and Lycalopex gymnocercus in five localities and determined the frequency of animals with antibodies against Toxoplasma gondii, Trypanosoma cruzi, Leishmania infantum, Neospora caninum, and Leptospira spp. Among the canids sampled, 23% (12/52) (95%CI: 13–36%) had antibodies against T. gondii, with titers ranging from 64 to 512. For T. cruzi, 28% (15/52) (95%CI: 18–42%) of sampled canids were seropositive, with titers ranging from 8 to 64. Concerning the protozoan pathogen N. caninum, a total of 5% (3/52) (95%CI: 2–15%) of wild canids had antibodies against it. None of the sampled canids showed the presence of antibodies against L. infantum. On the other hand, 44% (23/52) (95%CI: 31–57%) of the wild canids showed antibodies against Leptospira spp. The set of results presented here, show that free-ranging neotropical wild canids are exposed and have antibodies against to T. gondii, T. cruzi, Leptospira spp., and to a lesser degree to N. caninum. We found no evidence of L. infantum circulation among the studied populations. These results highlight some of the major pathogens which may represent risks for populations of these wild canids. Data Availability StatementThe data that support the findings of this study are available from the corresponding author upon reasonable request.

Survey of Zoonotic Bacterial Pathogens in Native Foxes in Central Chile: First Record of Brucella canis Exposure.

Simple SummaryWild canids play a crucial role in the environment, being an ecological agent of flora dispersal, top predators, and environmental sentinels for zoonotic emerging pathogens, such as Brucella spp. and pathogenic Leptospira. In Chile, three species of non-domestic native canids are present, and due to the growing concern about their interaction with humans and domestic animals, it is of utmost relevance to determine the role of these animals in the epidemiology of brucellosis and leptospirosis. This study aimed to detect the exposure to B. abortus, B. canis, and pathogenic Leptospira by serologic, bacteriologic, and molecular techniques in native foxes from rehabilitation and exhibition centers in Central Chile. Forty-six blood samples were obtained from culpeo and grey foxes, detecting exposure to B. canis and L. Javanica in 10.9% and 7.7%, respectively. Exposure was not registered by culture and qPCR in any of the sampled animals. Our results show for the first time in Chile exposure to B. canis in native foxes, highlighting the need to establish integrated surveillance programs to better evaluate the role of wild animals in the epidemiology of emerging zoonotic pathogens that may affect One Health.Brucella abortus, B. canis, and pathogenic Leptospira are zoonotic pathogens that infect humans, as well as domestic and wild animals. In wild canids, they may affect their fertility and reproduction, threatening their conservation. Wild canids play a crucial role in the environment as meso- and top-predators and environmental sentinels for zoonotic pathogens. In Chile, three species of wild canids are present, and due to changes in land use and environmental dynamics, it is of utmost relevance to determine the role of these species in the epidemiology of brucellosis and leptospirosis. This study aimed to detect the exposure to B. abortus, B. canis, and pathogenic Leptospira by serologic, bacteriologic, and molecular techniques in native foxes from rehabilitation and exhibition centers in Central Chile. Forty-six blood samples were obtained from Lycalopex culpaeus and L. griseus, detecting 10.9% of seropositivity to B. canis and 7.7% to L. Javanica. No seropositivity was seen for B. abortus. Exposure was not registered by culture and qPCR in any of the sampled animals. Our findings are the first register of exposure to any Brucella species in wild canids in Chile and highlight the need to establish surveillance programs of these emerging pathogens.

Virome of crab-eating (Cerdocyon thous) and pampas foxes (Lycalopex gymnocercus) from southern Brazil and Uruguay

Crab-eating (Cerdocyon thous) and Pampas foxes (Lycalopex gymnocercus) are wild canids distributed in South America. Domestic dogs (Canis lupus familiaris) and wild canids may share viral pathogens, including rabies virus (RABV), canine distemper virus (CDV), and canine parvovirus 2 (CPV-2). To characterize the virome of these wild canid species, the present work evaluated the spleen and mesenteric lymph node virome of 17 crab-eating and five Pampas foxes using high-throughput sequencing (HTS). Organ samples were pooled and sequenced using an Illumina MiSeq platform. Additional PCR analyses were performed to identify the frequencies and host origin for each virus detected by HTS. Sequences more closely related to the Paramyxoviridae, Parvoviridae and Anelloviridae families were detected, as well as circular Rep-encoding single-stranded (CRESS) DNA viruses. CDV was found only in crab-eating foxes, whereas CPV-2 was found in both canid species; both viruses were closely related to sequences reported in domestic dogs from southern Brazil. Moreover, the present work reported the detection of canine bocavirus (CBoV) strains that were genetically divergent from CBoV-1 and 2 lineages. Finally, we also characterized CRESS DNA viruses and anelloviruses with marked diversity. The results of this study contribute to the body of knowledge regarding wild canid viruses that can potentially be shared with domestic canids or other species.

Association of missense variants in GDF9 with litter size in Entlebucher Mountain dogs.

In the past two decades, average litter size (ALS) in Entlebucher Mountain dogs decreased by approximately 0.8 puppies. We conducted a GWAS for ALS using the single-step methodology to take advantage of 1632 pedigree records, 892 phenotypes and 372 genotypes (173662 markers) for which only 12% of the dogs had both phenotypes and genotypes available. Our analysis revealed associations towards the growth differentiation factor 9 gene (GDF9), which is known to regulate oocyte maturation. The trait heritability was estimated at 43.1%, from which approximately 15% was accountable by the GDF9 locus alone. Therefore, markers flanking GDF9 explained approximately 6.5% of the variance in ALS. Analysis of WGSs revealed two missense substitutions in GDF9, one of which (g.11:21147009G>A) affected a highly conserved nucleotide in vertebrates. The derived allele A was validated in 111 dogs and shown to be associated with decreased ALS (-0.75±0.22 puppies per litter). The variant was further predicted to cause a proline to serine substitution. The affected residue was immediately followed by a six-residue deletion that is fixed in the canine species but absent in non-canids. We further confirmed that the deletion is prevalent in the Canidae family by sequencing three species of wild canids. Since canids uniquely ovulate oocytes at the prophase stage of the first meiotic division, requiring maturation in the oviduct, we conjecture that the amino acid substitution and the six-residue deletion of GDF9 may serve as a model for insights into the dynamics of oocyte maturation in canids.

First epidemiological data on Spirocerca vulpis in the red fox: A parasite of clustered geographical distribution.

This is the first study describing the epidemiology of Spirocerca vulpis after its description as a new species in 2018. During the period 2006-2013, a total of 286 red foxes (Vulpes vulpes) from the Valencian Community (southeast Spain) were necropsied. Based on data collected, S. vulpis prevalence and intensity were calculated, as well as the spatial distribution of this nematode. Influence of host (sex and age) and environmental factors on S. vulpis occurrence was evaluated. MAXENT software was used to model and predict the parasite distribution. Continuous and discrete prediction maps were built using ArcMap 10.6. The prevalence of S. vulpis was 22% (63/286; 95% CI: 17.4-27.3), and the median intensity was 5 (IQR 11) nematode specimens. No significant difference in term of intensity was found between males and females; regarding the host age, S. vulpis was found only in adult foxes, with the exception of one juvenile individual. The distribution of S. vulpis in foxes was skewed to the left, highlighting that parasite infection affects few individuals within a population, with parasitized animals being responsible to maintain the infection at the population level. The majority of parasitized foxes had a parasite burden lower than eight parasites/individual. S. vulpis distribution in Valencian Community presents sharply defined areas in which there are optimal environmental conditions for maintaining the life cycle of this parasite. Climatic variables and altitude are the main factors influencing the parasite presence. Our results indicate that S. vulpis has epidemiological characteristics similar to those of S. lupi and, therefore, based on the phylogenetic proximity of both nematode species, it is likely that coprophagous beetle species might play a key epidemiological role in the maintenance of this newly described Spirocerca species. Moreover, it is currently unknown if S. vulpis can infect the dog and other wild canid species apart from the red fox and, if so, what are the pathogenic effects on these host species. Therefore, it is necessary to continue investigating the epidemiology of this parasite in order to know the range of appropriate host species. This information will enable to know if S. vulpis endemic areas should be considered as health risk points for dogs, especially for the most exposed, such as those living in rural areas, and hunting dogs.

Detection and genotyping of Toxoplasma gondii in wild canids in Serbia

To gain insight into the population structure of the protozoan parasite Toxoplasma gondii in wildlife in Serbia, multiplex nested PCR- RFLP was performed on T. gondii DNA positive samples of heart tissue of three wild canid species, including red foxes (Vulpes vulpes), golden jackals (Canis aureus) and grey wolves (Canis lupus). Out of 110 samples (28 red foxes, 72 golden jackals, 10 wolves), 30 (27.3%) were positive for T. gondii DNA, of which 24 were genotyped (nine red foxes, 13 golden jackals and two wolves). The results showed a large dominance of lineage II (n = 20, 83.4%) over lineage III (n = 4, 16.7%) strains. Lineage II comprised four archetypes, 14 variants and one which remained undetermined, while within lineage III there were three archetypes and one variant strain. However, a notable difference in diversity was observed among the examined canids, with eight (88.9%) of the nine strains detected in red foxes distinct, vs. six (46.1%) distinct strains of the 13 detected in golden jackals. Since anthropogenic food sources are a major reservoir of archetypal lineage II and III T. gondii strains, the results suggest that the golden jackal may be outcompeting the red fox, forcing it to hunt wild mammals and birds for sustenance, thereby increasing its chances of infection with variant strains. In addition to presenting the first data on the T. gondii population structure in wild canids in Serbia, this is the first report ever on T. gondii genotypes in golden jackals, a species with an increasing presence in Europe and another important reservoir of domestically circulating T. gondii strains.

The status of wild canids (Canidae, Carnivora) in Vietnam

Four species of wild canids are documented as occurring in Vietnam: Dhole Cuon alpinus, Eurasian Golden Jackal Canis aureus, Red Fox Vulpes vulpes and Raccoon Dog Nyctereutes procyonoides. Except for Dhole, all species are widely distributed globally and are listed as Least Concern on the IUCN Red List of Threatened Species. Concerned by the paucity of recent records of these species from Vietnam, especially in the context of rapidly declining mammal populations in the country in general, we undertook a review of the status of these species in Vietnam. All traceable and potentially verifiable canid records from 01 January 2002 until 31 December 2018 were collated and reviewed. The Dhole, formerly the most widely distributed of all canid species in Vietnam, and Raccoon Dog, apparently formerly widely distributed in the northern part of the country, appear to have both declined; Dhole is now either extirpated, or close to extirpation, while Raccoon Dog is of uncertain status. The Eurasian Golden Jackal does not seem to have been reliably observed in the wild since 2004, although it is possible the species may persist in some areas. Red Fox has only ever been known from a handful of records, and the current status of this species is unknown. In summary, Vietnam cannot be considered to sustain healthy populations of any of its four native wild canid species. These declines seem largely attributable to hunting of both the canids themselves and, for Dhole, their prey base, exacerbated by habitat loss. 

Endocranial Development in the Coyote (Canis latrans) and Gray Wolf (Canis lupus): A Computed Tomographic Study

The purpose of this study was to examine the pattern of postnatal brain growth in two wild canid species: the coyote (Canis latrans) and gray wolf (Canis lupus). Adult regional and total brain volume differences were also compared between the two species as well as within each species by sex. Three-dimensional virtual endocasts of endocranial airspace were created from computed tomography scans of 52 coyote skulls (28 female, 24 male; 1 day to 13.4 years) and 46 gray wolf skulls (25 female, 21 male; 1 day to 7.9 years). Age was known in coyotes or estimated from dentition patterns in wolves. The 95% asymptotic growth of the endocranium is completed by 21 weeks in male and 17.5 weeks in female coyotes and by 27 weeks in male and 18.5 weeks in female wolves. These ages are well before age at first reproduction (coyote – 40.4 weeks; wolf – 91.25 weeks). Skull growth as measured by centroid size lags behind endocranial growth but is also completed before sexual maturity. Intra- and interspecific comparisons of brain volumes in the adult wolves and coyotes revealed that relative anterior cerebrum (AC) volume was greater in males than females in both species. Relative brain size was greater in the coyote than in the wolf as was relative cerebrum volume. However, relative AC volume and relative cerebellum and brainstem volume was greater in the wolf than coyote. One explanation for the increased AC volume in males compared to females may be related to the role of social information processing. However, additional data are needed to determine the correspondence between regional volumes and functional differences either between or within these species. Nonetheless, these findings provide important baseline data for further studies on wild canid brain variations and development.

Dental and Temporomandibular Joint Pathology of the Grey Wolf (Canis lupus)

Skulls from 392 grey wolves (Canis lupus) were examined macroscopically according to predefined criteria. Two hundred and seven skulls were included in this study, comprised of 124 young adults (59.9%) and 83 adults (40.1%); of these, 65 (31.4%) specimens were from male wolves and 104 (50.3%) were from females, with 38 (18.4%) of unknown sex. Out of 8,694 possible teeth, 8,339 (95.9%) were present for evaluation. Fifty-five teeth (15.5%) were absent congenitally, 30 (8.5%) were lost during life and 270 (76.1%) were lost artefactually post mortem. Skeletal or dental malocclusion was present in 37 specimens (17.9%), with level bite being the most commonly encountered malocclusion. Enamel hypoplasia was present in five skulls (2.4%), affecting eight teeth (0.1%) in total. An abnormal number of roots was found on 23 teeth (0.3%) on 13 skulls (6.3%). Persistent deciduous teeth occurred in two (1.0%) specimens, affecting one (0.01%) tooth each. Fenestration or dehiscence was found associated with 203 teeth (2.4%) in 72 skulls (34.8%). Periodontitis was noted on 115 skulls (55.6%)and 1,000 teeth (11.5%), affecting significantly more adults (n=63, 75.0%) than young adults (n=52, 41.9%; P <0.0001). One hundred and sixty-one skulls (77.8%) showed signs of endodontal disease, including attrition or abrasion on 144 skulls (69.6%) and 2,522 teeth (30.2%)and 424 fractured teeth (5.1%) on 103 skulls (49.8%). Both lesions affected significantly more adults than young adults. Overt periapical disease was associated with six teeth (0.1%) distributed across five skulls (2.4%). A carious lesion was present on one tooth (0.01%) of one specimen (0.5%). Lesions consistent with temporomandibular joint (TMJ) osteoarthritis were found in 24 specimens (11.6%), affecting 38 joints (9.2%). Trauma to the skull, such as bite marks, bullet holes or blunt trauma, was noted in 44 skulls (21.2%). The grey wolf and the domestic dog (Canis lupus familiaris) share common dental diseases; however, the proportion and severity may vary. Although the clinical significance of dental and TMJ pathology in the grey wolf remains unknown, based on the impact of these disorders on the domestic dog, the occurrence and severity of these lesions are likely to play an important role in the morbidity and mortality of this wild canid species.

Occurrence and diversity of arthropod-transmitted pathogens in red foxes (Vulpes vulpes) in western Austria, and possible vertical (transplacental) transmission of Hepatozoon canis.

Red fox (Vulpes vulpes) is the most abundant wild canid species in Austria, and it is a well-known carrier of many pathogens of medical and veterinary concern. The main aim of the present study was to investigate the occurrence and diversity of protozoan, bacterial and filarial parasites transmitted by blood-feeding arthropods in a red fox population in western Austria. Blood (n = 351) and spleen (n = 506) samples from foxes were examined by PCR and sequencing and the following pathogens were identified: Babesia canis, Babesia cf. microti (syn. Theileria annae), Hepatozoon canis, Anaplasma phagocytophilum, Candidatus Neoehrlichia sp. and Bartonella rochalimae. Blood was shown to be more suitable for detection of Babesia cf. microti, whilst the spleen tissue was better for detection of H. canis than blood. Moreover, extremely low genetic variability of H. canis and its relatively low prevalence rate observed in this study may suggest that the parasite has only recently been introduced in the sampled area. Furthermore, the data presented here demonstrates, for the first time, the possible vertical transmission of H. canis from an infected vixen to the offspring, and this could explain the very high prevalence in areas considered free of its main tick vector(s).