Propagation of a Strain of Egg-Adapted Distemper Virus in Suckling Mice. ∗

Abstract

Summary

Two separate lines of the FXNO strain of egg-adapted canine distemper virus were passed intracerebrally in suckling mice 18 and 10 times, respectively. Both lines induced signs of protracted hyperkinesis. After the 7th passage central nervous system involvement became quite prominent and severe. Ataxia, muscular twitching, disequilibrium, paresis, and clonic spasms were common manifestations. The time of the first nervous disturbance decreased progressively from 8 days to 3 days in Line 1 and from 15 days to 4 days in Line 2. In ovo neutralization tests and ferret protection tests establish the identity of the mouse passaged agent with the original egg-adapted FXNO strain.