ANTHELMINTIC THERAPIES FOR PARAFILAROIDES DECORUS PNEUMONIA IN CALIFORNIA SEA LIONS (ZALOPHUS CALIFORNIANUS)

Infection with the lungworm Parafilaroides decorus is ubiquitous among young California sea lions (CSL; Zalophus californianus), and high infection intensity is a significant cause of pulmonary pathology, respiratory distress, morbidity, and mortality. Anthelmintics are a common treatment for stranded CSL exhibiting clinical evidence of pneumonia in the rehabilitation setting. To evaluate the clinical efficacy of anthelmintics in reducing larval lungworm fecal output, 55 stranded pup and yearling CSL were treated with either parenteral moxidectin or oral fenbendazole and compared with a group that did not receive an anthelmintic. Clinical disease scoring initially revealed 1 animal to not have disease, 37 animals to have mild to moderate disease, and 17 animals to have severe disease secondary to P. decorus infection. Initial posttreatment fecal recheck scored animals as improved (n = 30), unchanged (n = 14), worsened (n = 2), or dead (n = 9). There was no difference between treatment groups and changes in clinical scores on the basis of clinical signs, nor was there a difference between treatment groups and change of P. decorus presence. There is insufficient evidence to indicate that oral fenbendazole or subcutaneous moxidectin is superior for parasitic pneumonia therapy due to P. decorus in CSL.