Veterinary Parasitology 181 (2011) 75–82 Contents lists available at ScienceDirect Veterinary Parasitology jo u rn al hom epa ge : www.elsevier.com/locate/vetpar Prevalence pattern and biology of Sarcocystis capracanis infection in the Egyptian goats: A light and ultrastructural study Kareem Morsy a,∗ , Ahmed Saleh a , Ali Al-Ghamdi b , Fathy Abdel-Ghaffara a , Khaled Al-Rasheid c , Abdel-Rahman Bashtar a , Saleh Al Quraishy c , Heinz Mehlhorn d a Zoology Department, Faculty of Science, Cairo University, Egypt b Biology department, College of Science—Al Baha University, Al Baha, Saudi Arabia c Zoology department, College of Science, King Saud University, Riyadh, KSA d Department of Parasitology, Heinrich Heine University, Düsseldorf, Germany a r t i c l e i n f o Article history: Received 28 October 2010 Received in revised form 8 May 2011 Accepted 10 May 2011 Keywords: Sacocystis capracanis Light and ultrastructural studies Experimental infection a b s t r a c t Cysts of Sarcocystis capracanis obtained from infected goats were examined to clarify the effect of the parasite on the host. Muscle tissues from fresh oesophagus, tongue, diaphragm and skeletal muscles of 680 goats were slaughtered in the main abattoir of Cairo, Egypt and they were examined microscopically for Sarcocystis infection for the first time in Egypt. 540 out of 680 (79.4%) of examined goats were found to be infected with Sarcocystis sp. The infection was recorded firstly by light microscopy as spindle shaped cysts embedded in the muscle tissues. The validity of this species as S. capracanis was confirmed by means of ultrastructural characteristics of the primary cyst wall which revealed the presence of thick-radially striated wall with finger like projections, underlined by a thick layer of ground substance enclosing the developing metrocytes and merozoites that usually contain nearly all the structures of the apical complex and fill the interior cavity of the cyst. The cyst cavity is divided by many septa extending from the ground substance and producing large number of chambers. An experimental infection using the highly infected muscles was carried out to determine the final host, which is dog. Smears of intestinal epithelium were taken to examine the endogenous stages (gamogony and sporogony) by means of light microscopy. These stages were mainly observed as to infect the lamina propria of the posterior third of the small intestine. Gamogony and zygote formation (fertilization) occurred 2–8 days post infection, while sporulation took place within the final host 13–15 days and sporocysts were passed within faeces of the infected puppies at that time. The prepatent period of S. capracanis was 12–15 days, while the patent period was extended to 37 days. In goats, infection with S. capracanis led to the loss of weight, anaemia, abortion and even death in cases of heavy infection. While bleeding, watery faeces filled with mucous on 5th and 8th day p.i. as well as intestinal lesions are the pathogenic effects occurred in puppies after experimental infection. © 2011 Elsevier B.V. All rights reserved. 1. Introduction The Apicomplexa (Levine, 1970) constitute a large and diverse cosmopolitan protozoan phylum of obligate ∗ Corresponding author. Tel.: +20 10 2705803. E-mail address: kareemsaid156@yahoo.com (K. Morsy). eukaryotic intracellular parasites responsible for many serious diseases of humans, domestic animals and live- stock making these parasites economically important and suitable organisms for medical research (Gillis et al., 2003; Katayama et al., 2003). Species within genus Sarcocystis (Lankester, 1882) are obligate heteroxenous, cyst-forming parasitic Coccidian belonging to the family Sarcocystidae. These parasites 0304-4017/$ – see front matter © 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.vetpar.2011.05.010