EXPERIMENTAL INFECTION WITH Toxocara cati IN PIGS: MIGRATORY PATTERN AND PATHOLOGICAL RESPONSE IN EARLY PHASE

Abstract

Experimental inoculations of approximately 100,000 infective Toxocara cati larval eggs were done in twelve pigs. The T. cati eggs used for inoculation were collected from cat's feces. Another group of three pigs served as an uninfected control. Groups of infected pigs were euthanized at seven, 14, 21, and 28 days post-inoculation (dpi). Tissue samples were taken for digestion and histopathology changes in early phase. The number of larvae recovered from the lungs peaked at seven and 14 dpi and were also present at 21, and 28 dpi. Larvae of T. cati were present in the lymph nodes of the small and large intestine at seven, 14, and 28 dpi and at seven, 14, 21, and 28 dpi respectively. In other studied tissues, no larvae or less than one larva per gram was detected. The pathological response observed in the liver and lungs at seven and 14 dpi, showed white spots on the liver surface and areas of consolidation were observed in the lungs. The lungs showed an inflammatory reaction with larvae in center at 28 dpi. In the liver we observed periportal and perilobular hepatitis. The lymph nodes of the intestines displayed eosinophil lymphadenitis with reactive centers containing parasitic forms in some of them. The granulomatous reaction was not observed in any tissues. The role of the other examined tissues had less significance. The relevance of this parasite as an etiological agent that leads to disease in paratenic hosts is evident.

Histopathological lesions caused by experimental Toxocara canis and Toxascaris leonina infections in farm mink (Neovison vison)

“…(15), both CD4+ and CD8+ T lymphocytes were detected within and around Toxocara -induced granulomas as well as in isolated inflammatory foci in the portal tracts or within the hepatic parenchyma. During experimental infection with T. cati in pigs, periportal and perilobular hepatitis were observed (18). Moreover, hepatocytic necrosis was noticed in both T. canis -infected groups and T. leonina -egg-infected mink.…”

Serological examination of fattening pigs reveals associations between Ascaris suum, lung pathogens and technical performance parameters

“…Finally, larval stages of Toxocara spp. (Helwigh et al, 1999;Sommerfelt et al, 2014;Sommerfelt et al, 2004) or bacterial infections like tuberculosis or brucellosis (Komijn et al, 1999;Matlova et al, 2005;Tirkkonen et al, 2013) could also induce liver lesions that can be mistaken for white spot lesions caused by migrating A. suum larvae. However, these types of lesions are much more uncommon than Ascaris infections.…”

Migratory pattern of zoonoticToxocara catiandT. canisin experimentally infected pigs

“…in pigs is unknown, and larvae seem to find their way to most organs of the host. Previous studies have shown that T. canis larvae are found in the MLN and livers 14 dpi, with numbers peaking in the lungs one week later while similar larval numbers were found in lymph nodes and lungs at day 7 and 14 dpi in T. cati infected pigs (27,30,31,34). In contrast to T. canis, we recovered no T. cati from the livers at 14 dpi despite high numbers of white spots, suggesting that the larvae have left this organ at the time of necropsy.…”

“…Experimental studies in the pig assessing the migratory pattern and associated pathology of T. canis (25)(26)(27)(28)(29)(30)(31)(32)(33), and T. cati (34) have reported larval recoveries from a variety of organs and muscles, including lymph nodes, liver, lungs, eyes, kidneys, diaphragm, tongue, and masseter. While the large majority of the experimental studies in pigs have focused on either T. canis or T. cati, only a single comparative study has been performed.…”