RESUMEN
Macrocysts of S. fusiformis were teased out from the oesophageal muscles of infected buffaloes and a suspension of cyst extract with protein concentration of 2mg/ml was used as uncooked [UE] and cooked [CE] form. Thirty six healthy male laboratory rabbits were divided into six equal groups randomly. Group I and II were inoculated with UE, group III and IVwere inoculated with CE and group Vand VI were inoculated with PBS orally and intraperitonealy [1 ml/kg] respectively. Blood samples were taken in 0, 3, 6, 24 hrs, 3 and 7 days after inoculation. Coagulation tests including BT, CT, PT, APTT, fibrinogen level and platelet count were measured at the different times which mentioned in all groups. Statistical analysis showed significant differences between different times of all tests in group II compare to other groups [p < 0.05]. The study showed that IP inoculation of UE of S. fusiformis at protein concentration of 2mg/ml is lethal to rabbits about 24 hr after inoculation, and caused significant changes in blood coagulation tests in different times. The results also showed that S.fusiformis extract toxin was thermolabile as it was inactivated at 60 ?Cfor 30 min. In addition oral administration of the cysts extract did not make any changes in both cooked and uncooked form. Thus it seems that orally inoculation of S. fusiformis cysts extract had no toxic effects on coagulation tests mentioned above in rabbits because the toxin is probably susceptible to the gastric enzymes and low pH of the stomach