EXPERIMENTALLY INDUCED MENINGEAL WORM (PARELAPHOSTRONGYLUS TENUIS) INFECTION IN THE LLAMA (LAMA GLAMA): CLINICAL EVALUATION AND IMPLICATIONS FOR PARASITE TRANSLOCATION

Abstract

Six adult llamas (Lama glama) were experimentally infected with five larval Parela phostrongylus tenuis each. Neurologic, anatomic, and cerebrospinal fluid changes were assessed, and the potential for llamas to develop patent meningeal worm infections was evaluated. Clinical signs first appeared on days 45-53 postinfection. Onset of clinical signs was significantly associated with the age of the llama. Neurologic deficits characteristically appeared in the hind limbs first and progressed to the front limbs. Four of six llamas developed fatal infections, with clinical signs lasting between 20 and 80 days. No consistent abnormalities were present in cerebrospinal fluid total protein, glucose, aspartate aminotransferase, or creatine kinase, thus limiting their value as diagnostic indicators of infection. All llamas developed an eosinophilic pleocytosis in the cerebrospinal fluid, but the day on which it appeared differed. Histologie lesions compatible with parasite migration were present, primarily in the cervical spinal cord, in five of six llamas. Although two of six llamas survived the duration of the study, evidence of reproducing meningeal worm populations was absent. Risk of llamas transporting patent meningeal worm populations to nonendemic areas is considered minimal.