Dog imported from Ethiopia found with zoonotic parasite Linguatula

Abstract

A moderate number of oval-shaped, 114.7 × 61.3 μm in size, amber-colored, arthropod-like eggs that had chitinous, smooth, semi-thickened outer wall and 2-4 short appendages armed with 2 terminal hook-like structures were detected in multiple fecal samples from an approximately 9-month-old, intact female, collie-mixed dog that had been recently imported from Ethiopia to Oklahoma, United States. Initially the unusual arthropod-like eggs were considered to be a pseudoparasite, most likely mite eggs. However, based on the history of the dog, morphology of the eggs, and presence of the eggs in repetitive fecal flotations, a pentastomid, Linguatula serrata, was suspected. DNA extraction and PCR analysis of the partial 18S rRNA gene were performed on the eggs, and nucleic acid sequence showed 100% homology to L. serrata, a parasite of dogs, and L. arctica, a parasite of Norwegian reindeers. Rhinoscopy and head CT scan on the dog failed to demonstrate adult parasites or detect any pathologic changes. At this time, pentastomid eggs were no longer observed on fecal flotation. Due to the possibility of juvenile stages of the parasite still migrating in the dog, fluralaner (Bravecto®, Merck) was administered and continuing treatment recommended for at least 6 months. A follow-up fecal examination conducted a month after the treatment did not reveal any parasites or eggs. This is a case report of canine linguatuliasis diagnosed in Oklahoma, United States.