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This article explores the health challenges faced by sled dogs in the Canadian Arctic during the 19th century. As outsiders began to explore the region, they discovered the importance of using dog teams and wearing furs for warmth. However, diseases like distemper and rabies posed a threat to the dogs, with accounts of dogs exhibiting symptoms of hydrophobia (rabies) being recorded. Firsthand accounts from expeditions led by Dr. Elisha Kane and Dr. Isaac Israel Hayes describe the symptoms and deaths of their dogs, although the cause of these health issues remains unclear. The article also discusses the experiences of explorers Charles Francis Hall and Sir George S. Nares, who faced challenges with their dogs, including a mysterious disease that caused seizures and death. The explorers attempted various treatments, some of which may have contributed to the deaths of the dogs. The author emphasizes the need for a better understanding of the fate of these animals and acknowledges the limitations of medical knowledge during that time period. [Extracted from the article]

The genus Protoparvovirus (family Parvoviridae) includes several viruses of carnivores. We describe a novel fox protoparvovirus, which we named Newlavirus as it was discovered in samples from Newfoundland and Labrador, Canada. Analysis of the full non-structural protein (NS1) sequence indicates that this virus is a previously uncharacterized species. Newlavirus showed high prevalence in foxes from both the mainland (Labrador, 54/137, 39.4%) and the island of Newfoundland (22/50, 44%) but was not detected in samples from other carnivores, including coyotes (n = 92), lynx (n = 58), martens (n = 146), mink (n = 47), ermines (n = 17), dogs (n = 48), and ringed (n = 4), harp (n = 6), bearded (n = 6), and harbor (n = 2) seals. Newlavirus was found at similar rates in stool and spleen (24/80, 30% vs. 59/152, 38.8%, p = 0.2) but at lower rates in lymph nodes (2/37, 5.4%, p < 0.01). Sequencing a fragment of approximately 750 nt of the capsid protein gene from 53 samples showed a high frequency of co-infection by more than one strain (33.9%), high genetic diversity with 13 genotypes with low sequence identities (70.5–87.8%), and no geographic segregation of strains. Given the high prevalence, high diversity, and the lack of identification in other species, foxes are likely the natural reservoir of Newlavirus, and further studies should investigate its distribution. [ABSTRACT FROM AUTHOR]

Many pathogenic mycobacteria are known to cause severe disease in humans and animals. M. avium subspecies paratuberculosis ( Map ) is the causative agent of Johne's disease-a chronic wasting disease affecting ruminants such as cattle and sheep, responsible for significant economic losses in the dairy and beef industries. Due to the lack of treatment options or effective vaccines, mitigating losses can be difficult. In addition, the early stages of Map infection may occur in asymptomatic hosts that continue to shed viable bacteria in their faeces, leading to the infection of other healthy animals. Using multi-locus short sequence repeat (ML-SSR) analysis we previously reported that individual Johne's positive dairy cattle from farms across the island of Newfoundland were infected by Map with multiple SSR-types simultaneously. The occurrence of multiple mixed genotype infections has the potential to change pathogen and disease dynamics as well as reduce the efficacy of treatments and vaccines. Therefore, we conducted whole genome sequencing (WGS) and single nucleotide polymorphism (SNP) analysis on a subset of these isolates for a more in-depth examination. We also implemented a PCR assay using two discriminatory SNPs and demonstrated the incidence of a mixed infection by three genotypically diverse Map isolates in a single animal. In addition, results show that WGS and SNP analysis can provide a better understanding of the relationship between Map isolates from individual and different animals. In the future such studies on the occurrence of mixed genotype infections could potentially lead to the identification of variable pathogenicity of different genotypes and allow for better tracking of Map isolates for epidemiological studies., Competing Interests: The authors declare there are no competing interests.