Experience from sentinel health monitoring in units containing rats and mice in experiments

Abstract

The paper contains the results of 15 months of sentinel health monitoring in four different animal units, of which three were protected by a barrier, and one was operated without any protective procedures. Rat and mouse sentinels were placed in
the units on contaminated bedding for three months and hereafter tested for the following infections: Ectromelia Virus, Kilham Rat Virus (KRV), Lymphocytz's Choriomeningizis Virus (LCM), Minute Virus of Mice (MVMj, Mouse Hepatitis Virus (MHV), Pneumoniuvirus of Mice (PVM), Rai Coronavirus, Reovirus type 3, Sendai Virus, Theiler’s Encephalomyelitis Virus (TMEV), Toolan’s H1 Virus, Bordetella branchisepzica, Citrobacler freundii. Clostridium piliforme, Corynebacterium kutscheri, Mycaplasma spp, Pasteurella pneumotropica, Salmonellae, B-haemolytic Streptoeocci, Streptococcus pneumoniae, arthropods, helminths, Eimeria rpp and flagellates. The outcome of the sentinel investigations were compared with the knowledge on the health status of those animals, which were purchased for experiments in the four units. In the non-proteeted unit antibodies to KR V, PVM and C1 piliforme were refound in the sentinel rats, as it had been found in the purchased animals. Additionally, eggs of Syphacia spp. were found in the non-proteeted unit. P. pneumnrropica, which was also introduced into three of the units with purchased rats and mice, was cultivated from sentinel mice, only, and not from sentinel rats. Both rat and mouse sentinels were found positive to P1 pneumotropica by serology. PVM and C. piliforme, which had been introduced with purchased gerbils and rats and were refound in the sentinel rats, were not found in the sentinel mice. MH V and Rat Coronaviruses were, independently, detected in two of the units. Both coronaviruses were easily eradicated by simply euthanizing all animals of the susceptible species with no precautions taken against animals of other species within the unit. LCM did not spread from experimentally infected mice to the sentinels. Concerning the use of serology for coronaviruses, parvoviruses, C. piliforme and P. pneumotropica it is concluded that the dirty bedding technique proved efficient. For bacteriological and parasitological investigations in general, as well as for serological investigations for LCM and PVM, the method seemed less efficient.