Echinococcus species (spp.) are regarded as neglected cestodes causing several potential zoonoses of global public health. This systematic review critically appraises the worldwide distribution of Echinococcus spp. and genotypes (Echinococcus spp.: recognized species in the genus; genotypes: variants identified within E. granulosus sensu lato.) in definitive hosts. We analyzed 82 studies from major databases, comprising 24 individual host species, including canids, felids, and a hyenid species. Canids, particularly dogs, were the most studied group among the host species, with E. granulosus sensu stricto (G1-G3) being the most frequently reported. E. granulosus s.s. was distributed across five major continents, while other Echinococcus spp. and genotypes exhibited an uneven continental distribution. The highest overlap of species existed among Asia, Europe, and Africa. Among the reported host species, 4.2 % were endangered (e.g. Lycaon pictus), 12.5 % species were vulnerable (e.g. Panthera leo, Panthera pardus, and Acinonyx jubatus), and 4.2 % were near threatened (e.g. Speothos venaticus). Overall, our review highlights the significance of canids, particularly dogs, as the core focus of scientific investigations, with E. granulosus s.s. being the most widely distributed species across five major continents, emphasizing the urgent need for continued research and public health efforts.

Domestication has long been considered the most powerful evolutionary engine behind dramatic reductions in brain size in several taxa, and the dog (Canis familiaris) is considered as a typical example that shows a substantial decrease in brain size relative to its ancestor, the grey wolf (Canis lupus). However, to make the case for exceptional evolution of reduced brain size under domestication requires an interspecific approach in a phylogenetic context that can quantify the extent by which domestication reduces brain size in comparison to closely related non-domesticated species responding to different selection factors in the wild. Here, we used a phylogenetic method to identify evolutionary singularities to test if the domesticated dog stands out in terms of relative brain size from other species of canids. We found that the dog does not present unambiguous signature of evolutionary singularity with regard to its small brain size, as the results were sensitive to the considerations about the ancestral trait values upon domestication. However, we obtained strong evidence for the hibernating common raccoon dog (Nyctereutes procyonoides) being an evolutionary outlier for its brain size. Therefore, domestication is not necessarily an exceptional case concerning evolutionary reductions in brain size in an interspecific perspective.

African wild dogs (Lycaon pictus) are unique among canids in their specialized hunting strategies and social organization. Unlike other, more omnivorous canids, L. pictus is a hypercarnivore that consumes almost exclusively meat, particularly prey larger than its body size, which it hunts through cooperative, exhaustive predation tactics. Its bite force is also among the highest reported for carnivorans. Here, we dissected an adult male L. pictus specimen and conducted diffusion iodine contrast-enhanced computed tomography (diceCT) scans to evaluate and describe its masticatory and oral cavity musculature. Muscles of mastication in L. pictus are separated by deep layers of thick intermuscular fascia and deep insertions. The superficial surface of m. masseter is entirely covered by an extremely thick masseteric fascia. Deep to m. masseter pars reflexa and superficialis are additional bellies, m. masseter pars profunda and zygomaticomandibularis. Musculus temporalis in L. pictus, divides into suprazygomatic, superficial, and deep bellies separated by a deep layer of thick intermuscular fascia, and it inserts along the entire rostral margin of the mandibular ramus. Musculus digastricus appears to comprise a single, large fusiform belly which appears to receive its innervation exclusively from CN V3 (nervus mandibularis, division of nervus trigeminus). Musculus pterygoideus medialis and lateralis are each composed of a single, deep belly. However, despite its great bite force, the jaw adductor muscle mass in L. pictus is not increased for its body size over other canid taxa. This finding suggests there are other architectural adaptations to hypercarnivory beyond increased muscle volume (e.g., pennation angle, greater strength, optimization of lever arms for mechanical advantage).

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.

Echinococcus spp. is an emerging zoonotic parasite of high concern. In Canada, an increase in the number of human and animal cases diagnosed has been reported, but information regarding the parasite\'s distribution in wildlife reservoir remains limited. A cross-sectional study was conducted to estimate the prevalence of wild canids infected with Echinococcus spp. and Echinococcus multilocularis in areas surrounding populated zones in Québec (Canada); to investigate the presence of areas at higher risk of infection; to evaluate potential risk factors of the infection; and as a secondary objective, to compare coproscopy and RT-PCR diagnostic tests for Taenia spp. and Echinococcus identification. From October 2020 to March 2021, fecal samples were collected from 423 coyotes (Canis latrans) and 284 red foxes (Vulpes vulpes) trapped in 12 administrative regions. Real-time PCR for molecular detection of genus Echinococcus spp. and species-specific Echinococcus multilocularis were performed. A total of 38 positive cases of Echinococcus spp., of which 25 were identified as E. multilocularis, were detected. Two high-risk areas of infection were identified. The prevalence of Echinococcus spp. was 22.7% (95% CI 11.5-37.8%) in the Montérégie centered high-risk area, 26.5% (95% CI 12.9-44.4%) in the Bas-St-Laurent high-risk area, and 3.0% (95%CI 1.8-4.7%) outside those areas. For E. multilocularis, a prevalence of 20.5% (95% CI 9.8-35.3%) was estimated in the high-risk area centered in Montérégie compared to 2.4% (95% CI 1.4-3.9%) outside. Logistic regression did not show any association of infection status with species, sex, or geolocation of capture (p > 0.05). This study shows the circulation of Echinococcus in a wildlife cycle in 9/12 administrative regions of Québec.

This study aimed to assess the fusion of growth plates and the development of secondary ossification centres in the forelimb bones of maned wolves (Chrysocyon brachyurus), contrasting the findings with established data from domestic dogs. Three maned wolves, comprising one male and two females, initially aged between 3 and 4 months, were subjected to monthly radiographic evaluations until 10-11 months of age, followed by bimonthly assessments until 18-19 months of age, encompassing both forelimbs. The closure times of growth plates were observed as follows: supraglenoid tubercle (7-8 months), proximal humerus (17-19 months), distal humerus (8-9 months), medial epicondyle of the humerus (8-9 months), proximal ulna (9-10 months), proximal radius (13-15 months), distal ulna (13-15 months) and distal radius (17-19 months). Statistical analysis revealed significant differences in the areas of secondary ossification centres in the proximal epiphyses of the humerus and radius, respectively, observed from the initial evaluation at 8-9 months and 6-7 months. Conversely, the epiphyses of the supraglenoid tubercle, distal humerus, proximal ulna, distal ulna, medial epicondyle of the humerus and distal radius did not exhibit significant area differences between 3-4 months and 4-5 months, yet notable distinctions emerged at 5-6 months. In summary, while the radiographic appearance of epiphyseal growth plates and secondary ossification centres in maned wolves resembles that of domestic dogs, closure times vary. These findings contribute to understanding the dynamics of epiphyseal growth plates in this species.

The mammalian vomeronasal system enables the perception of chemical signals crucial for social communication via the receptor families V1R and V2R. These receptors are linked with the G-protein subunits, Gαi2 and Gαo, respectively. Exploring the evolutionary pathways of V1Rs and V2Rs across mammalian species remains a significant challenge, particularly when comparing genomic data with emerging immunohistochemical evidence. Recent studies have revealed the expression of Gαo in the vomeronasal neuroepithelium of wild canids, including wolves and foxes, contradicting predictions based on current genomic annotations. Our study provides detailed immunohistochemical evidence, mapping the expression of V2R receptors in the vomeronasal sensory epithelium, focusing particularly on wild canids, specifically wolves and foxes. An additional objective involves contrasting these findings with those from domestic species like dogs to highlight the evolutionary impacts of domestication on sensory systems. The employment of a specific antibody raised against the mouse V2R2, a member of the C-family of vomeronasal receptors, V2Rs, has confirmed the presence of V2R2-immunoreactivity (V2R2-ir) in the fox and wolf, but it has revealed the lack of expression in the dog. This may reflect the impact of domestication on the regression of the VNS in this species, in contrast to their wild counterparts, and it underscores the effects of artificial selection on sensory functions. Thus, these findings suggest a more refined chemical detection capability in wild species.

Canine-transmitted worms and an uncontrolled deworming program of stray dogs have caused that accurate diagnosis of zoonotic parasites received notable attention in endemic regions. This study aimed to assess the presence of E. multilocularis and E. granulosus infections in canids from Guilan province, northern Iran. A total of 272 fecal samples from carnivores were collected across 24 different regions in Guilan province between 2023 and 2024. All fecal specimens were observed following concentration and flotation techniques. DNAs of taeniid eggs were extracted, amplified, and sequenced targeting of specific mitochondrial Cox1 gene for E. granulosus and NAD 1 gene for E. multilocularis. On the base of molecular and phylogenetic analysis 1.47 % (in jackal) and 25 % (in dogs and jackal) of samples were positive for E. multilocularis and E. granulosus sensu strico G1 genotype, respectively. Molecular technique was found to be more sensitive in detecting infection in comparison with conventional techniques. Sequence analysis of Cox1 indicated a high genetic diversity (Haplotype diversity; 0.933; Number of haplotypes, h: 7) in E. granulosus G1. Current findings show that canids particularly jackals play potential role of definitive host in maintenance and transmission dynamic of E. multilocularis and E. granulosus in northern Iran. The presence of these infections is of particular concern in Guilan province due to the high influx of tourists, increasing the risk of transmission to humans. Therefore, the implementation of preventive programs is warranted to apply hygienic practices and adjusting deworming programs for the canids and at-risk individuals in the region.

Europe has suffered unprecedented epizootics of high pathogenicity avian influenza (HPAI) clade 2.3.4.4b H5N1 since Autumn 2021. As well as impacting upon commercial and wild avian species, the virus has also infected mammalian species more than ever observed previously. Mammalian species involved in spill over events have primarily been scavenging terrestrial carnivores and farmed mammalian species although marine mammals have also been affected. Alongside reports of detections of mammalian species found dead through different surveillance schemes, several mass mortality events have been reported in farmed and wild animals. In November 2022, an unusual mortality event was reported in captive bush dogs (Speothos venaticus) with clade 2.3.4.4b H5N1 HPAIV of avian origin being the causative agent. The event involved an enclosure of 15 bush dogs, 10 of which succumbed during a nine-day period with some dogs exhibiting neurological disease. Ingestion of infected meat is proposed as the most likely infection route.

The evolutionary lineage and taxonomy of the Australian dingo is controversial, however recent genomic and gut metagenomic research has suggested that dingoes are evolutionarily distinct from modern dogs. Staphylococcus species are known commensal organisms of dogs and other mammals. In this study we took the opportunity to determine the carriage rate and antimicrobial resistance profiles of Staphylococcus species from 15 captive Australian dingoes. S. pseudintermedius was the only coagulase-positive species recovered, isolated from 6/15 (40%) and 9/13 (69%) of the animals during the 2020 (winter) and 2021 (summer) sampling times, respectively. Twenty-three coagulase-negative isolates were characterised, with S. equorum being the most frequently (20/23, 87%) recovered species. Two isolates of S. equorum had their genomes sequenced to learn more about this species. Antimicrobial resistance amongst both coagulase-positive and -negative isolates was low; with resistance to only 3 of 12 antimicrobials observed: penicillin, erythromycin, and trimethoprim. We have shown that the Australian dingo is a host organism for S. pseudintermedius much like it is in dogs, however the carriage rate was lower than has previously been reported from dogs in Australia.