Pathological effects of Cryptocotyle lingua in double-crested cormorants (Phalacrocorax auritus) treated with dexamethasone

One observation reported in dead common loons, the large numbers of Cryptocotyle lingua found in weak birds, suggests that an underlying disease problem may cause impairment of the immune system of the birds that leads to an increased degree of parasitism, causing further debilitation. This study intended to replicate the infection caused by C. lingua , an intestinal trematode normally present in small numbers in adult seabirds that die in good body condition, with no signs of a debilitating disease. Replication of the infection caused by C. lingua was conducted in immunocompetent and immunosuppressed seabirds, specifically double-crested cormorants, Phalacrocorax auritus. The birds were collected from a wild colony at 2 weeks of age and raised in captivity until the experimental trial began at 2 months of age. A total of 31 double-crested cormorants (DCC) were divided into 4 different treatment groups: an immunosuppressed/infected group (n = 8), an immunosuppressed/non-infected group (n = 7), a non-immunosuppressed/infected group (n = 8) and a non-immunosuppressed/non-infected group (n = 8). (Abstract shortened by UMI.).