Introduction

The genus Dirofilaria includes various species and those worms are natural parasites of dogs, cats, foxes and wild mammals. It is well known that identifying the species in this genus is difficult because of their sizes, proportions, spicules and caudal papillae.

Objectives

The present study describes the cuticular morphology of adult D. immitis from the peritoneal cavity of a dog in Korea.

Methods

Two worms were found in the fat of the umbilical cord area during operation for an umbilical cord hernia in a dog (four-year-old, female Maltese). The worms were tentatively identified under the light microscope, before precise classification using a scanning electron microscope (SEM).

Results

In gross findings, the worms were slander white and measured 132 mm (female), 111 mm (male). The tail of the male was spirally coiled. In light microscopy, the uterus was filled with not fully developed eggs. Scanning electron microscopy revealed that the cuticle was smooth on the head, but those of the tail exhibited complex cuticular striation in the male. Head papillae were located in a cephalic plate forming a rectangular pattern dorsoventrally, with 4 inner labial papillae and 4 outer cephalic papillae. The mouth opening was very small and the bursal cavity was absent. Laterally there was a pair of amphids.

Conclusions

In our study, 4 pairs of preanal papillae were seen, and arrangement of the preanal papillae was demonstrated by micrographs of the tails of two males.