Gongylonema sp. infection in the scops owl (Otus scops)

Abstract

Since 1997, it has been observed that fledging scops owls often develop necrotic plaques in their oral cavities, which in severe cases can even affect bone tissue. This condition has been defined as a necrotic oropharyngeal disease based on gross lesions. In 2011 alone, thirty-five cases were identified at the Brinzal Owl Rescue Centre (Madrid, Spain), of which four were chosen to perform a complete diagnostic study. Histopathology was carried out in three cases and cytology in one case. Using morphological traits cytology identified two larvae as third-stage larvae of a Spiruridae nematode. Histology detected parasite sections in the mucosal epithelium of the mouth of one owl. In addition, four samples of mucosal lesions were subjected to a PCR amplification of the nematode ribosomal RNA gene using a pair of universal primers, three of which were positive. Of available sequences, the sequence obtained showed the closest affinity to that of Gongylonema pulchrum (97.8–98.0%). Clinical treatment was based on supportive therapy, the daily removal of caseous material from the oral cavity and the administration of fenbendazol (50mg/kg PO for 5days). Approximately 60% of the affected scops owls that arrived at the rescue centre in 2011 were cured and released back into the wild. Clinical, pathological and molecular findings are consistent with Gongylonema sp. infection. Since no evidence of the presence of adult parasites was found, we suggest that these scops owls should be considered as accidental hosts. This is the first description of severe Gongylonema infection in fledgling scops owls, a disease can lead to starvation and death if proper treatment is not provided.