Novel Papillomaviral Sequence Detected within Epidermal Plaques in a Wolf (Canis lupus)

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.

MUSKRATS (ONDATRA ZIBETHICUS) ARE COMPETENT INTERMEDIATE HOSTS OF ECHINOCOCCUS MULTILOCULARIS IN NORTH AMERICA

The tapeworm Echinococcus multilocularis is an emerging pathogen of significance to human and animal health in Canada, yet little is known about key rodent intermediate hosts in local urban ecosystems. In Europe, invasive muskrats (Ondatra zibethicus) are an important indicator intermediate host species; however, the role of this semiaquatic rodent in the ecology of E. multilocularis is undetermined in the North American context. We examined 93 muskrats that were livetrapped in the spring of 2017 within Calgary, Alberta, Canada, for the presence of E. multilocularis infection. The objectives of this study were to 1) diagnose alveolar echinococcosis using macroscopic assessment, histopathology, and molecular analyses; 2) quantify infection severity; and 3) assess host demographic risk factors for infection. Macroscopic cysts consistent with alveolar echinococcosis were present in 24% of muskrats (22/93). Most individuals had hepatic cysts; however, cysts were also occasionally detected in the mesentery, reproductive organs, omentum, peritoneum, spleen, diaphragm, lung, or kidney. The mean number of cysts per liver was 2.1 (range, 1-4). We examined hepatic cysts from 18 individuals using histology; all had lesions compatible with alveolar echinococcosis. Protoscoleces, indicative of patent infections, were present in 14/18 (78%). No demographic risk factors (sex, body condition, body mass) were significantly associated with infection. Muskrats in the North American context are competent intermediate hosts with high infection prevalence and may play an important role in the ecology of this emerging parasite.

Morphological and Immunohistochemical Description of a Splenic Haemangioma in a Captive European Wolf (Canis lupus lupus) and a Review of the Current Literature

Neoplastic diseases are rarely described in wild carnivores; only a few reports have been published on this topic. Here, we describe the histological and immunohistochemical features of a haemangioma in the spleen of a grey wolf (Canis lupus lupus) and we compare the results with the dog (Canis lupus familiaris). Additionally, we list the different publications found in the literature with neoplastic lesions in wolves. Our results show similar immunohistochemical features to dogs, in which neoplastic cells express Vimentin, von Willebrand factor, alpha smooth muscle actin antibody, vascular endothelial growth factor C and low vascular endothelial growth factor receptor 3. Toluidine blue special stain shows moderated increased numbers of mast cells infiltrating the tumor, a feature observed in benign vascular tumors in domestic dogs, but not in the malignant counterparts. To our knowledge, this is the first article describing the gross, histological and immunohistochemical features of a splenic haemangioma in a wolf.

Clinico-Histopathological and Immunohistochemical Study of Ruminant's Cutaneous Papillomavirus in Iraq

The papilloma viruses are constituted of double-stranded DNA and are a more common lesion in ruminant's skin in Iraq. The p53 tumor suppressor protein reveals an essential role in cell cycle control. This study intends to investigate the clinical, histopathological, and immunohistochemical features of cutaneous papilloma in ruminants in Iraq. Samples had been collected from a total of 10 animals (three cattle, three goats, and four sheep) with multiple papillomatosis lesions. The samples were processed for histopathological and immunohistochemical techniques. Clinically, the lesions appeared as multiple various sizes (0.5–11 cm), cauliflower exophytic masses on different parts of the animal's body. The histopathological features of the epidermis granular layer revealed perinuclear vacuolation (koilocytosis) accompanied by various degrees of hypergranulosis, hyperkeratosis, acanthosis, orthokeratosis, and parakeratosis. Strong positive reaction for papillomavirus antigen was seen in both epidermal basal and granular layers in the immunohistochemical investigation (IHC). Moreover, all papilloma lesions revealed an intense positive p53 reaction in cytoplasmic and perinuclear of the basal and parabasal layers. In conclusion, this study described the papillomavirus lesions in bovine, ovine, and caprine animals, which were found in different parts areas of the affected animals. All lesions show similar histopathological features with minor variations. PV antigen and p53 protein expression showed positive results in immunohistochemistry that can be used as diagnostic markers for ruminant's papilloma.

Lambdapapillomavirus 2 in a Gray Wolf ( Canis lupus ) from Minnesota, USA with Oral Papillomatosis and Sarcoptic Mange

Oral papillomatosis was diagnosed in a gray wolf ( Canis lupus ) with sarcoptic mange from Minnesota, US found dead in February 2015. Intranuclear inclusion bodies were evident histologically, and papillomaviral antigens were confirmed using immunohistochemistry. Sequencing of the L1 papillomavirus gene showed closest similarity to Lambdapapillomavirus 2.