Eimeria stiedae: weight, oocyst output, and hepatic function of rabbits with graded infections

Groups of 5 (38–40 days old) Eimeria stiedae-naive rabbits were infected with 0 (mock infection), 10², 10³, 10⁴, and 10⁵ sporulated oocysts of Eimeria stiedae (groups A, B, C, D, and E, respectively) and body weight, oocyst output, serum glutamic pyruvic and serum oxalacetic transaminases, bilirubinemia. lipemia, glycemia, and proteinemia were measured on diverse occasions for 50 days. Mortality and carcass and liver weights at the end of the experiment were also recorded. Mortality was 80% in group E, 40% in group D, and 0% in the other groups. Reduction of weight gain was observed from the 8th day of infection and actual loss from the 15th day in infected animals. On Day 50, the average body and carcass weights of all infected rabbits were 71.2 and 63.2%, respectively, of group A. Only groups D and E had absolute hepatomegaly and group C had relative liver enlargement. Patency and rate of increase of oocyst output were not related to dose but peak and declination of oocysts production were delayed in proportion to the infective dose.Serum glutamic pyruvic and glutamic oxalacetic transaminases were increased from Day 8 to Day 36, bilirubinemia and lipemia augmented from Day 22, and glycemia and total serum proteins decreased from Days 22 and 29, respectively. Bilirubinemia tended to recover sooner (toward Day 50) in rabbits with lighter infection and lipemia recovered from Day 36 in proportion to the size of the infective dose. Modifications of glycemia and total proteinemia were consistent but reached statistical significance only occasionally. The asexual reproduction of the parasites caused transient damage to the hepatocytes during the second week of infection, and later sexual stages altered the ductal epithelium from the fourth week.