Abstract
BACKGROUND: Toxocara cati is a known cause of a zoonotic infectious illness called toxocariasis. Parathenic hosts are important as they can transmit larvae 2 (L(2)) through direct transmission. Scanning electron microscope (SEM) techniques are needed to provide a three-dimensional image of each stage of T. cati larvae. AIM: The aim of this study was to determine the morphology of L(2) and L(3) T. cati in parathenic host tissue for etiological diagnosis using SEM. METHODS: Mice were used as suitable paratenic hosts for this experiment. A total of 786 embryonated eggs (16 eggs/gram body weight) containing L(2) were inoculated into pregnant mice at day 11-13 of its gestation period. After delivery, L(2) was transmitted to the off-spring. After 14 days, L(2) was collected from mice, and L(3) was collected from its off-spring. Data were analyzed descriptively based on ultrastructure examination using SEM. RESULTS: SEM examination results indicate that the size of L(2) is smaller than L(3). Results also showed differences between L(2) and L(3) based on middle and posterior observations. In the middle of the larval body, the number of L(2) body rings was observed to be narrower and more than that of L(3). In addition, the distance between L(2) body rings was much larger than that of L(3). Posteriorly, the tail tip of L(3) was more curved than L(2). CONCLUSION: Ultrastructural examination using SEM has the ability to show differences in L(2) and L(3) body rings of T. cati by observing the middle and posterior parts of its larvae.