Biology of Cooperia punctata (Nematoda: Trichostrongylidae) in the Domestic Rabbit

Abstract

Young, domestic rabbits (Oryctolagus cuniculus), maintained under controlled conditions, are suitable hosts for the propagation of Cooperia punctata (v. Linstow, 1907) Ransom, 1907, an intes- tinal nematode parasite of domestic ruminants. Normal cooperid eggs, passed in the feces of infected rabbits, were cultured to secure characteristic infective third-stage larvae. The prepatent period for these infections ranged from 11 to 16 days (average 13 days) and was comparable to the prepatent period for infections in calves, a normal host. The length of the prepatent period was not influenced by the source and size of the larval dose nor by the sex and breed of the rabbit. However, age of the host appeared to influence susceptibility. The number of nematodes collected from an infected rabbit varied from 10 to 9,863 (average 1,796), which was in the range of 0.01 to 9.20% (average 2.52%) of the dosage administered. The number of nematodes that developed in relation to the dosage administered appeared to be affected by the sex of the rabbit, 3.37 and 1.55% for males and females, respectively. The infectivity of C. punctata in rabbits did not seem to change in a series of five suc- cessive passages. The patent period, based on the rabbit host, ranged from 3 to 38 weeks (average 12 weeks). It was not affected by age and breed of host nor by the source and size of the larval dose, but was affected by sex. The patent period for male rabbits ranged from 3 to 38 weeks (average 14 weeks), and for female rabbits from 5 to 16 weeks (average 9 weeks). The postpatent period ranged from 1 to 13 weeks (average 3 weeks). The distribution of nematodes in the small intestine of rabbits varied with the period of infection and shifted from the posterior to the anterior half of the intestine with increased duration of the patent period.