Ferrets were monitored daily post-inoculation for morbidity and clinical signs of infection as previously described [29] . Any ferret which lost .25% of its pre-inoculation body weight or exhibited neurological dysfunction was euthanized. Virus shedding was measured on alternate days post-inoculation (p.i.) in nasal washes (NW), conjunctival washes (CW), and rectal swabs (RS). NW and RS samples were collected as previously described [28, 29] . CW were obtained by bathing the inoculated (right) ferret eye three times with 500 ml wash solution (PBS containing Pen/Strep, Gentamycin, and BSA) and collecting the run-off in a small petri dish, then swabbing the surface and surrounding conjunctival tissue of the right eye with a pre-wettened cotton swab for 5 seconds, and placing the swab in a collection tube containing the run-off liquid. All samples were immediately frozen on dry ice and stored at 270uC until processed.