Disease and Mortality in Free-Ranging Leporids in Canada, 1990-2019: A Retrospective Study.

Passive surveillance of wildlife disease is a valuable tool for the identification of emerging and changing disease patterns. Free-ranging leporids play an important role in their ecosystem and in the culture and diet of Canadians; however, little is known about their health status and the zoonotic pathogens they may carry. We summarized major causes of mortality and morbidity, as well as incidental infections and lesions, of free-ranging leporids submitted to the Canadian Wildlife Health Cooperative (CWHC) between 1990 and 2019. We identified Canadian leporids as competent hosts for several zoonotic pathogens, most notably Francisella tularensis (20/569; 3.5%). Trauma was the most frequent cause of mortality or morbidity among leporids, accounting for 46.0% of cases submitted to the CWHC, followed by bacterial infections (13.7%) and emaciation (5.1%). Human-mediated mortalities, such as those involving machines (23.7%), were the most common trauma case type, with apparently healthy individuals overrepresented within this mortality group. Harvesters proved to be a valuable resource for the monitoring of diseased and infected animals, as more than half (69.6%) of the animals submitted by this group had an incidental infection or lesion. The results from this study provide a scientific understanding the cause of mortality in free-ranging leporids in Canada with relevance to public health, wildlife biologists, veterinarians, and potential future surveillance programs.

An assessment of the environmental and socio-economic impacts of alien rabbits and hares.

Directly comparable data on the environmental and socio-economic impacts of alien species informs the effective prioritisation of their management. We used two frameworks, the Environmental Impact Classification for Alien Taxa (EICAT) and Socio-Economic Impact Classification for Alien Taxa (SEICAT), to create a unified dataset on the severity and type of impacts caused by alien leporids (rabbits and hares). Literature was reviewed to collate impact data, which was categorised following EICAT and SEICAT guidelines. We aimed to use these data to identify: (1) alien leporid species with severe impacts, (2) their impact mechanisms, (3) the native species and local communities vulnerable to impacts and (4) knowledge gaps. Native species from a range of taxonomic groups were affected by environmental impacts which tended to be more damaging than socio-economic impacts. Indirect environmental impacts were particularly damaging and underreported. No impact data were found for several alien leporid species.

A Versatile qPCR for Diagnosis of Leporid Gammaherpesvirus 5 Using Evagreen® or Taqman® Technologies.

In late 2019, the first herpesvirus in the genus Lepus, named leporid gammaherpesvirus 5 (LeHV-5) was described. At the time, herpetic typical lesions were observed in hares infected by the myxoma virus, which is known to induce immunosuppression. Though the real impact of LeHV-5 is still poorly understood, since it affects reproduction, it poses an additional threat to the already fragile populations of Iberian hare, demanding prevalence investigations. In this article, we describe the first quantitative molecular method for LeHV-5 detection, using either Taqman or the EvaGreen systems. This method has excellent sensitivity and specificity, it is able to detect 2.1 copies of LeHV-5 DNA and was validated with an internal control targeting the 18S rRNA gene, allowing monitoring extraction and PCR amplification efficiencies.