No significant difference was noted in canine hookworm infection due to hormone influence between the control group and the gonadectomized rats which were sacrificed 17 days after gonadectomy and 7 days after the infection. However in the rats which were infected 20 days after oophorectomy a significant difference was thought to be present in this group(176 +- 12.9 larvae/rat) compared with the control group (138 +- 21.2 larvae/rat). On the other hand, in the castrated group the number of larvae (138 +- 37.1 larvae/rat) was less than that in the control group (208 +- 43.4 larvae/rat). In the estrogen-injected male and female groups, there were no difference compared to the control, but the testosterone-injected groups of males and females showed more susceptibility to infection by A. caninum than in the control group. The Capillaria hepatica infection to the castracted host showed no significant difference between the gonadectomized and the control group. (oophorectomy; 214 +- 28.0), castration; 250 +- 36.5 and control; 191 +- 58.2 and 270 +- 30.1 adults/rat). Concerning the influence of the host's sex hormone on egg production of canine hookworm, there was a significantly decreased egg production in castrated dogs(6,578 +- 664.0 egg per gram) compared to the control dogs(9,711 +- 1,322.3 egg per gram). The same results were observed in vitro test. In the host, the susceptibility to hookworm infection was reduced in castrated rats, while oophorectomy group had a little or no effect. In the favorable or unfavorable hosts, testosterone gave the tendency of increasing susceptibility of the host to infection, while estrogen did a little or no effect.
parasitology-helminth-nematoda ; hookworm ; estrogen ; testosterone ; rat ; dog Ancylostoma caninum ; Capillaria hepatica ; gonadectomy ; estrogen ; testosterone

One hundred and two stray dogs in Ejungbu City of Kyunggi-Do, Korea were examined to reveal out the degree of natural helminthic infection of small intestine. Helminthes were collected at autopsy, by scraping the intestinal contents. The collected worms were classified by their morphological characteristics. Out of 102 examined, 72 dogs were infected with any helminthes. The common helminthes were Dipylidium caninum (47 percent), Ancylostoma caninum (26 percent), Toxascaris leonina (16 percent) and Toxocara canis (13 percent). Taenia pisiformis (9 percent), Echinostoma hortense (4 percent), E. cinetorchis (2 percent), Spirometra mansoni (2 percent) were also found. One dog was incidentally found to be infected with Clonorchis sinensis. The prevalence of Toxascaris leonina was relatively high in this study over Toxocara canis, and its significance was discussed. Dogs were firstly described as the reservoir hosts of Echinostoma hortense and E. cinetorchis in Korea.
parasitology-helminth-nematoda-trematoda ; cestoda ; dog ; epidemiology ; morphology ; Dipylidium caninum ; Ancylostoma caninum ; Toxascaris leonina ; Toxocara canis ; Taenia pisiformis ; Echinostoma hortense ; Echinostoma cinetorchis ; Spirometra mansoni ; reservoir host ; intermediate host

Helminthic zoonoses are of significant importance to the public health and to the socioeconomic consequences especially in lost-meat, animal products and animal labor. For past several decades in Korea, it has been recognized that endoparasitic infections among domestic animals are extremely common and many of the helminth parasites of man have been acquired from, or are shared with domestic animals. However, there was no survey of a nationwide scale on the prevalence of animal helminthiasis; and control measures are also not satisfactory. Furthermore, because of the remarkable increase in the demand, number of domestic animals and pets is rapidly increasing in these days. Therefore, an extensive study on zoonotic helminths was carried out from July 1980 throughout August 1981 to understand the present status and parasite-host relationship from the epidemiological viewpoont. A total of 13,685 fecal specimens of cattles, sheeps, pigs, dogs and cats was collected from 26 localities in the country. The specimens were examined by formalin-ether centrifugal sedimentation technique. The results are summarized as follows: Of 13,685 specimens examined, 9,808(71.7 percent) were positive for helminth parasites. The positive rates were 99.0 percent in cattles, 86.5 percent on sheeps, 85.4 percent in pigs, 35.4 percent in dogs, 15.1 percent in cats. Single infection showed the highest rate (60.0 percent), and double infection(27.5 percent), triple(8.1 percent), quadruple(2.8 percent), quintuple(1.5 percent) and hexad(0.1 percent) were in decreasing order. In the present study, 18 species zoonotic helminths were found: 11 nematodes, 6 trematodes and 1 cestode. According to province, Cheju revealed the highest rate 84.8 percent, then Kyungnam 77.5 percent, Jeonnam 75.6 percent, Jeonpuk 75.4 percent, Kyonggi 75.2 percent, Chungnam 71.7 percent, Chungpuk 70.6 percent and Kangwon 64.2 percent were in decreasing order and Busan and Seoul showed 70.4 percent and 58.1 percent, respectively. Rural area showed slightly higher rate (74.7 percent) than urban area (68.5 percent), and rates of mountainous area (70.4 percent) and plain area (71.1 percent) are very similar. According to animal, helminths species and positive rates appeared in: Cattles: 6 nematodes and 3 trematodes; Strongyles 26.4 percent, Neoascaris vitulorum 24.1 percent, Trichuris ovis 12.0 percent, Nematodirus sp. 6.3 percent, Srongyloides papillosus 5.1 percent, Capillaria bovis 0.02 percent, Paramphistomum sp. 41.5 percent, Fasciola hepatica 33.2 percent and Eurytrema pancreaticum 29.7 percent. Sheeps: 3 nematodes and 2 trematodes: Strongyles 33.0 percent, S. papillosus 26.9 percent, Nematodirus sp. 14.6 percent, F. hepatica 31.7 percent and E. pancreaticum 19.6 percent. Pigs: 5 nematodes and 2 trematodes: Strongyles 43.1 percent, Ascaris suum 29.0 percent, Metastrongylus apri 20.3 percent, Trichuris suis 14.0 percent, Strongyloides ransomi 12.1 percent, Clonorchis sinensis 1.4 percent and Paragonimus westermani 0.9 percent, Dogs: 4 nematodes and 3 trematodes and 1 cestode: Toxocara canis 14.4 percent, Trichuris vulpis 9.5 percent, Ancylostoma caninum 8.0 percent, Toxascaris leonina 4.0 percent, C. sinensis 2.4 percent, Metagonimus yokogawai 1.3 percent, P. westermani 0.8 percent and Spirometra sp. 0.9 percent, Cats: 2 nematodes, and 3 trematodes and 1 cestode: Toxocara cati 7.7 percent, Ancylostoma tubaeforme 3.1 percent, C. sinensis 1.9 percent, P. westermani 1.4 percent, M. yokogawai 1.2 percent and Spirometra sp. 0.7 percent.
parasitology-helminth-nematoda-trematoda-cestoda ; cattle ; sheep ; pig ; dog ; cat ; epidemiology ; zoonosis ; Fasciola hepatica ; Eurytrema pancreaticum ; Paramphsitomum sp. ; Neoascaris vitulorum ; Trichuris ovis ; Strongyloides papillosus ; Nematodirus sp. ; Capillaria bovis ; Clonorchis sinensis ; Paragonimus westermani ; Ascaris suum ; Trichuris suis ; Strongyloides ransomi ; Metastrongylus apri ; Spirometra sp. ; Metagonimus yokogawai ; Toxocara canis ; Toxocara leonina ; Ancylostoma caninum ; Trichuris vulpis ; Ancylostoma tubaeforme ; Strongyles