Microfilaria identified in a penguin
Cheryl Maguire, DVM, Mindy Borst, LVT
An unidentified microfilaria was found on a blood smear obtained from a 16-year old, female, captive penguin who was being treated for respiratory aspergillosis. The attending veterinarian submitted whole blood and a fresh blood smear to the Texas A&M Veterinary Medical Diagnostic Laboratory (TVMDL) for parasite identification. Multiple microfilariae were seen on the submitted blood smear as well as on freshly prepared blood smears from submitted EDTA whole blood.
Figure 1. The average length and width of the microfilaria is ~188 um x 5 um with no tapered tail present, effectively ruling out Dirofilaria immitis.
EDTA whole blood was forwarded to the Diagnostic Parasitology Laboratory at the Texas A&M University College of Veterinary Medicine and Biomedical Sciences for further parasite identification. PCR results identified the parasite as belonging to the subfamily Splendidofilariina with the most likely genus being Paronchocerca sp.
Splendidofilaria are a subspecies of avian filarial worms most of which are not pathogenic. Pathogenicity is even more rarely reported in association with microfilaria. The significance of this finding is unclear but ruling out Dirofilaria immitis in this case was important as only one case of adult D. immitis has been reported previously in a captive penguin.
Learn more about TVMDL testing by visiting tvmdl.tamu.edu or calling one of our full-service laboratories.
References:
- Bartlett, C. (2008) Parasitic Diseases of Wild Birds, Ch 26. Edited by Carter T. Atkinson, D. Bruce Hunter, Nancy J. Thomas. John Wiley & Sons, Inc.
- Y. Sano, M. Aoki, H. Takahashi, M. Miura, M. Komatsu, Y. Abe, J. Kakino, T. Itagaki. The First Record of Dirofilaria immitis Infection in a Humboldt Penguin, Spheniscus humboldti. J. of Parasitology, 91(5):1235-1237 (2005). https://doi.org/10.1645/GE-3492-RN.1