Mai T. Duong * , Han N. N. Vu , Giang T. Tran , & Mai C. Duong

* Correspondence: Duong Tieu Mai (email: mai.duongtieu@hcmuaf.edu.vn)

Main Article Content

Abstract

The objective of this study was to determine the development phases of Toxocara canis eggs outside the host and the migration of larvae in the internal organs of chickens infected by ingestion of embryonated T. canis eggs. Under a microscope observation of T. canis eggs which were incubated in a petri dish containing 5 mL of distilled water at 30 – 33oC with regularly aerated, this study showed the development of T. canis egg through various stages, including one cell, two cells, three cells, four cells, early morula, late morula, blastula, gastrula, tadpole, pre-larva, embryonated larva. In addition, it took approximately 9 days for T. canis eggs to hatch and for infective larvae to develop at 30 - 33oC. A total of 50 chickens were randomly assigned to 3 groups including group I (10 chicks/group) was served as control group without T. canis eggs inoculation; two treatment groups II and III (20 chicks/group) were orally inoculated with 500 or 1000 T. canis eggs, respectively. On 1, 3, 6, 15 and 30 days post inoculation (dpi), two chickens/control group and 4 chickens/treatment group were necropsied. The results showed that the percentage of larvae recovered varied from 14.00 to 33.93% and 13.07 to 32.00% in treatment groups II and III, respectively. After 1, 3, 6, and 30 dpi, the significant differences about the number of larvae recovered in two treatment groups were found (P < 0.05). In both treatment groups, the percentage of larvae recovered from livers was higher than that in lung tissue. For 6 dpi, small white foci on the liver’s surface were seen. Interstitial pneumonia, petechial hemorrhages, dark or gray inflammatory nodules in the lung tissue and the atelectatic area were observed. Histopathology examination revealed infiltrations of leukocytes and eosinophil scattered in the liver and lung tissue.

Keywords: Chicken, Larvae infection, Toxocara canis

Article Details

References

Abou-El-Naga, I. F. (2018). Development stages and viability of Toxocara canis eggs outside the host. Biomédica: Revista del Instituto Nacional de Salud 38(2), 189-197. https://doi.org/10.7705/biomedica.v38i0.3684.

Beaver, P. C. (1956). Larva migrans. Experimental Parasitology 5(6), 587-621. https://doi.org/10.1016/0014-4894(56)90032-7.

Brun̆aská, M., Dubinský, P., & Reiterova, K. (1995). Toxocara canis: ultrastructural aspects of larval moulting in the maturing eggs. International Journal for Parasitology 25(6), 683-690. https://doi.org/10.1016/0020-7519(94)00183-O.

Burren, C. H. (1972). The distribution of Toxocara canis larvae in the central nervous system of rodents. Transactions of the Royal Society of Tropical Medicine and Hygiene 66, 937-942. https://doi.org/10.1016/0035-9203(72)90131-9.

Cruz, L. M., Allanson, M., Kwa, B., Azizan, A., & Izurieta, R. (2012). Morphological changes of Ascaris spp. eggs during their development outside the host. Journal of Parasitology 98(1), 63-68. https://doi.org/10.1645/GE-2821.1.

Flecher, C. M., Musso, C., Martins, I. V. F, & Pereira, F. E. L. (2016). Larval migration of the ascarid nematode Toxocara canis following infection and reinfection in the gerbil Meriones unguiculatus. Journal of Helminthology 90 (5), 569-576. https://doi.org/10.1017/S0022149X15000760.

Galvin, T. J. (1964). Experimental Toxocara canis infections in chickens and pigeons. The Journal of Parasitology 50 (1), 124-127. https://doi.org/10.2307/3276045.

Glickman, T. L., & Schantz, M. P. (1981). Epidemiology and pathogenesis of zoonotic toxocariasis. Epidemiologic Reviews 3(1), 230-250. https://doi.org/10.1093/oxfordjournals.epirev.a036235.

Ito, K., Sakai, K., Okajima, T., Quchi, K., Funakoshi, A., Nishimura, J., Ibayashi, H., & Tsuji, M. (1986). Three cases of visceral larva migrans due to ingestion of raw chicken or cow liver. Nippon Naika Gakkai Zasshi 75, 759-766. https://doi.org/10.2169/naika.75.759.

Magnaval, J. F., Glickman, L. T., Dorchies, P., & Morassin, B. (2001). Highlights of human toxocariasis. Korean J. Parasitol 39(1), 1-11. https://doi.org/10.3347/kjp.2001.39.1.1.

Maruyama, S., Nino, T., Yamamoto, K., & Katsube, Y. (1994). Parasitism of Toxocara canis larvae in chickens inoculated with Ascarid eggs. Journal of Veterinary Medical. Science 56(1), 139-141. https://doi.org/10.1292/jvms.56.139.

Nagakura, K., Tachibana, H., Kaneda, Y., & Kato, Y. (1989). Toxocariasis possibly caused by ingesting raw chicken. The Journal of Infectious Diseases 160(4), 735-736. https://doi.org/10.1093/infdis/160.4.735.

Nakamura, S., Sotoyama, T., Hayasaka, S., Kameyama, Y., Maruyama, S., & Katsube, Y. (1991). Parasitism of Toxocara canis larvae in Japanese quails by inoculation of the ascarid eggs Journal of Veterinary Medical Science 53(5), 865-872. https://doi.org/10.1292/jvms.53.865.

Okoshi, S., & Usui, M. (1968). Experimental studies on Toxascaris leonina. VI. Experimental infection of mice, chickens and earthworms with Toxascaris leonina, Toxocara canis and Toxocara cati. The Japanese Journal of Veterinary Science 30(3), 151-166. https://doi.org/10.1292/jvms1939.30.151.

Oshima, T. (1961). Standardization of techniques for infecting mice with Toxocara canis and observation on the normal migration routes of the larvae. The Journal of Parasitology 47(4), 652-656. https://doi.org/10.2307/3275079.

Pahari, T. K., & Sasmal, N. K. (1991). Experimental infection of Japanese quail with Toxocara canis larvae through earthworms. Veterinary Parasitology 39(3-4), 337-340. https://doi.org/10.1016/0304-4017(91)90051-V.

Santos, S. V., Lescano, S. Z., Castro, J. M., & Chieffi, P. P. (2009). Larval recovery of Toxocara cati in experimentally infected Rattus norvegicus and analysis of the rat as potential reservoir for this ascarid. Mem Inst Oswaldo Cruz 104(6), 933-934. https://doi.org/10.1590/S0074-02762009000600020.

Schacher, J. F. (1957). A contribution to the life history and larval morphology of Toxocara canis. The Journal of Parasitology 43(6), 599-612. https://doi.org/10.2307/3286548.

Taira, K., Saitoh, Y., & Kapel, C. M. (2011). Toxocara cati larvae persist and retain high infectivity in muscles of experimentally infected chickens. Veterinary Parasitology 180, 287-291. https://doi.org/10.1016/j.vetpar.2011.03.020.

Taira, K., Permin, A., & Kapel, C. M. O. (2003). Establishment and migration pattern of Toxocara canis larvae in chickens. Parasitology Research 90(6), 521-523. https://doi.org/10.1007/s00436-003-0894-6.