Linguatula serrata (Pentastomida: Linguatulidae) infection in a paucisymptomatic greyhound imported from Romania to Italy: A case report and literature overview

Background: Linguatula serrata is a pentastomid zoonotic parasite with worldwide distribution. Although some cases of L. serrata infection have been reported in dogs, the epidemiology of this parasite remains largely unknown in developed countries. In recent years, canine linguatulosis has been repeatedly linked to cases of imported infections. This study aims to focus attention on this uncommon parasite through the presentation of a case report and an overview of the literature. Case description: A 1-year-old intact female Borzoi imported from Romania to Italy sneezed spontaneously a worm-like parasite specimen. Morphological and molecular diagnosis identified the parasite as a female of the zoonotic pentastomid L. serrata (so-called European tongue worm) that lives in the nasopharyngeal tract of canids. Eggs of Linguatula were detected in the feces. Molecular identification (99%-100% homology) was based on DNA extraction, polymerase chain reaction of a 700-bp fragment of the mitochondrial cytochrome c oxidase subunit I gene, and alignment with BLAST analysis. Due to the possibility of other adult or juvenile specimens of the parasite still occurring in the dog, a treatment attempt with a combination of febantel/pyrantel/praziquantel was made. No parasite eggs were detected in fecal samples after the drug was administered. Endoscopy confirmed the absence of adult parasites and slight pathological changes. A follow-up examination conducted 3 months after the treatment did not reveal any clinical and laboratory abnormalities. Conclusion: Linguatula serrata appears to be currently prevalent in some European countries, but there are no recent extensive studies on the prevalence of canine linguatulosis, so the parasite frequently remains undetected and unreported in dogs as the diagnosis is often overlooked. Parasites not commonly found such as L. serrata can become increasingly prevalent and may be detected in imported dogs. Therefore, veterinarians must be aware of the possible presence of uncommon and exotic pathogens in these dogs, be able to recognize the relevant clinical signs, and diagnose the infection quickly. This will improve the prognosis in individual dogs, reduces the risk of possible public health implications, and reduces the risk of uncommon and exotic pathogens establishing new endemic foci.