Cranial lesions possibly associated with Skrjabingylus (Nematoda: Metastrongyloidea) infections in martens, fishers, and otters

Abstract

Skulls of 631 martens (Martes americana), 810 fishers (Martes pennanti), and 373 otters (Lutra canadensis) collected throughout Ontario were examined for frontal bone lesions possibly induced by sinus nematodes of the genus Skrjabingylus. No lesions were found in marten skulls. Lesions were present in 13.4% of otter skulls and their distribution was similar between sexes and among age-groups. Among fishers, 11.6% of skulls exhibited lesions. Frequency of lesions tended to increase with age, and adult male fishers had fewer than adult females. Lesions were characterized by discolouration, swelling, and perforation of frontal bones in descending order of frequency. Lesions were largely confined to the pars temporalis of the frontal bones with a small number also found on the pars frontalis.