Lungworm (Crenosoma goblei) Infection in Unweaned Free-Ranging Raccoons (Procyon lotor) in Washington State, USA

First Molecular Identification and Clinical Presentation of Crenosomosis in a Dog from Slovakia

PURPOSE

Crenosoma vulpis (Dujardin,1845) is a lungworm which has spread worldwide in canines and is associated with upper respiratory infections. In a majority of cases, the infections are accompanied with chronic cough. Diagnosis of lungworms is often underdiagnosed and can be misinterpreted as other respiratory diseases.

METHODS

The Small Animal Clinic of the University Veterinary Hospital admitted an 11-month-old dog presented with persistent cough associated with difficulty in breathing and even asphyxia. Based on clinical symptoms, the patient underwent radiological and bronchoscopic examination. Bronchoscopy revealed the presence of lungworms obturating the branches of the tracheobronchial tree. Larvae were collected by bronchoscopic lavage and subjected to parasitological and molecular examination.

RESULTS

Microscopic detection and morphological identification of the worms removed during the bronchoscopy confirmed the presence of female adult worms. The subsequent molecular characterisation of the mitochondrial (cytochrome c oxidase subunit I gene (cox1) and 12S ribosomal DNA (rDNA)), nuclear (18S rDNA) genes, as well as the analysis of the second internal transcribed spacer (ITS-2) region of the ribosomal DNA, confirmed the Crenosoma vulpis species. Faecal samples were processed using the Baermann method, which confirmed the presence of the larval stage 1 of C. vulpis. The therapy with fenbendazole at a dose of 50 mg/kg of live weight once daily for the period of 7 days was initiated for the patient.

CONCLUSION

This paper presents the first molecularly confirmed clinical case of a Crenosoma vulpis infection in an 11-month-old female dog of the Miniature Schnauzer breed in Slovakia.

Diversity of Crenosoma species in mustelids with the first molecular characterization of C. melesi and C. petrowi

Species of genus Crenosoma have a wide distribution and are reported in Europe, the Americas, and Asia. Currently, the genus includes 14 nominal species, out of which 9 are parasitic in mustelids. Two species are mostly reported in mustelids from Europe, namely C. melesi and C. petrowi. Up to now, no genetic sequences are deposited in GenBank for any of the two. The aims of this study were to investigate the distribution, prevalence, and diversity of Crenosoma spp. infecting mustelids in Romania and to genetically characterize the species. Mustelids (n = 247) were collected over a period of 7 years from different locations in Romania and the respiratory tract was removed and examined for nematodes. Detected nematodes were morphologically identified and fragments of two genes were sequenced. Sampled mustelids included Eurasian badger, Meles meles (n = 102), Eurasian otter, Lutra lutra (n = 20), beech marten, Martes foina (n = 36), European pine marten, Martes martes (n = 5), steppe polecat, Mustela eversmanii (n = 1), European mink, Mustela lutreola (n = 1), least weasel, Mustela nivalis (n = 2), European polecat, Mustela putorius (n = 78), and marbled polecat, Vormela peregusna (n = 1). Nematodes from Eurasian badgers were morphologically identified as C. melesi (n = 13, 12.74%) and C. petrowi (n = 3, 2.94%). Nematodes from the beech martens were identified as C. petrowi (n = 6, 16.66%), C. vulpis (n = 1, 2.78%) and Crenosoma spp. (n = 3, 8.33%). Co-infections with two Crenosoma species were detected in one beech marten (C. petrowi + C. vulpis, n = 1, 2.77%) and in one European pine marten [C. petrowi + C. vulpis (n = 1, 20%)]. Two genes of Crenosoma melesi and C. petrowi were partly sequenced for the first time. We report new host-parasite associations for M. martes and C. vulpis. However, further studies are needed in order to determine the host-parasite associations and to improve the understanding of the epidemiology of Crenosoma nematodes.

Description of Crenosoma vismani n. sp., parasitic in the lungs of Lynx lynx (L.) (Carnivora: Felidae), with identification key to the species of the genus Crenosoma Molin, 1861 (Nematoda: Crenosomatidae)

A new species of Crenosoma Molin, 1861 is described from the lungs of the Eurasian lynx, Lynx lynx (L.) (Carnivora: Felidae). Crenosoma vismani n. sp. differs from other species of the genus in the morphology of the male copulatory organs (two ventral rays originating from a common stem; three lateral rays with common stem; gubernaculum 79-92 μm long, well developed, spoon-shaped; spicules 232-253 μm long, slightly curved, with robust dorsal appendage) and a vulva with rounded, prominent vulvar cuticular appendage is located in middle region of body in females. An analysis of the morphology and life-cycle data for Crenosoma petrowi Morozov, 1939 from Ursus americanus Pallas indicate that this nematode should be described as a new species. The validity of Crenosoma schulzi Gagarin, 1958 is resurrected. A new identification key for the species of Crenosoma is provided. Published records of the genus Crenosoma from definitive hosts and patterns of host specificity are presented. Morphological data revealed that the genus Crenosoma should contain 15 species (14 with valid names) with different host specificity, ranging from oioxenous to euryxenous. However, a review of the current genetic data indicates that the actual number of Crenosoma spp. is greater, and the host range is still unknown, even in Europe.