Abstract
A small caesarian-derived colony of albino rats was established in 1960 and has been maintained apparently free of specific pathogens by a simple and inexpensive method. The prevalence of disease, parasite infestations and other abnormalities has been compared in the caesarian-derived colony with rats of the same strain kept under conventional conditions.
The investigation has shown that rats of the caesarian-derived colony were free from chronic respiratory disease, lice, worms in the urinary bladder, tape-worms, bartonellosis, salmonellosis, labyrinthitis and various minor infections, all of which were prevalent in rats kept under conventional conditions. Animals of both colonies were subject to a low incidence of tumours, which were of various types in the caesarian-derived rats but mainly mammary carcinomas in the controls. A haemorrhagic hepatic disease occurred for a short time in both colonies. The most prevalent congenital abnormality was one associated with hydronephrosis, pyelonephritis and a haemorrhagic renal disease; both colonies had a similar prevalence of these lesions. Occasional cases of hydrocephalus, situs inversus, cleft lip and cleft palate, microphthalmia and absent organs were observed in both colonies.
The study has indicated that there are considerable advantages in using caesarian-derived rats in preference to conventional stock in experimental work.