EUCOLEUS BOEHMI INFECTION IN THE NASAL CONCHAE AND PARANASAL SINUSES OF RED FOX (VULPES VULPES) ON PRINCE EDWARD ISLAND, CANADA.

ABSTRACT

Eucoleus boehmi (Nematoda Capillariidae) occurs in the nasal conchae and paranasal sinuses of wild and domestic canids. We surveyed the red fox ( Vulpes vulpes ) on Prince Edward Island, Canada, for E. boehmi infection and characterized the associated histopathology. Nasal capillarid infections were detected based on histologic examination of three coronal sections of the nasal cavity and by centrifugal flotation examination (CFE) of rectal feces. Capillarids were detected in histologic sections in 28 of 36 (78%) foxes; detection occurred most frequently in the caudal section (28 foxes) and least in the rostral section (10 foxes). Adult worm morphology was typical for capillarids (stichosome esophagus, bacillary bands, bipolar plugged eggs); E. boehmi eggs were specifically identified based on the characteristic pitted shell wall surface. Adult worms were detected in histologic sections in all 28 and E. boehmi eggs in 21 of the positive foxes. No eggs of Eucoleus aerophilus were observed in any of the sections. Affected foxes had an eosinophilic and lymphoplasmacytic rhinitis with goblet cell hyperplasia. Eggs of E. aerophilus were detected on CFE in 20 of 36 (56%) foxes; 19 of the histologically positive foxes were coinfected with E. aerophilus. Eggs of E. boehmi were detected on CFE in 26 of 36 (72%) foxes and were consistent in size and morphology with those described from wild canids, but they differed from those reported from cases of infection in dogs. Prevalence based on identification of eggs on histologic section or CFE indicated 27 of 36 (75%) red foxes examined were infected with E. boehmi.