Toxocara cati larval migration in rats: experimental histopathological study

Toxocara spp. (T. canis and T. cati in particular) are the major etiological nematodes that have contributed to visceral larval migrans (VLM). So to show the ability of T. cati to produce such migration in the rats as experimental model and detection through histopathological observations to detect larval migratory patterns. Adult females T. cati were collected from naturally infected feral cats. Eight rats, Rattus norvegicus had acted as a model for experimental infection, each receiving an infectious dose of about 1000 infective T. cati eggs, while 2 rats served as non-infected control group. Two infected rats were sacrificed and examined at 7, 14, 21, and 28 day post infection (dpi) and tissue samples were taken for digestioning order to recover migrated larvae and for histopathological examination. In vitro embryonation of T. cati eggs was successfully carried out, although the percentage of embryonation was 10%, prepared inoculums were also infective to rats. Larvae recovered from the lungs at 7 and 14 dpi and were also present at 21, and 28 dpi. The larvae of T. cati were present in the intestines at 14, and 21 dpi. There were no larvae or less than one larva per gram found in other studied tissues. Histopathological changes in different organs were observed. Generally speaking, a multi-tissue response can be defined as the histopathological response of T. cati larval migration. The migratory larvae of T. cati can cause severe histopathological alterations in various tissues and organs of infected animals, within the current study shows that the lungs are a favorable site of migration for these larvae. T. cati is a zoonotic parasite that is underestimated.