M. Niezgoda et al., Viral excretion in domestic ferrets (Mustela putorius furo) inoculated with a raccoon rabies isolate, AM J VET RE, 59(12), 1998, pp. 1629-1632
Objective-To determine susceptibility incubation and morbidity periods, cli
nical signs of infection, serologic response, and excretion of virus in dom
estic ferrets inoculated with rabies virus of raccoon origin.
Animals-54 domestic ferrets.
Procedure-5 groups of ferrets were inoculated IM with the rabies virus. Ora
l cavity swab specimens and saliva were obtained for virus isolation. Blood
was obtained for virus-neutralizing antibody determination. If clinical si
gns were severe, ferrets were euthanatized immediately. Salivary gland and
brain tissue was collected for virus isolation and rabies diagnosis, respec
tively.
Results-Of 51 inoculated ferrets, 19 (37%) were euthanatized with clinical
signs of rabies. Mean incubation period was 28 days (range, 17 to 63 days).
Clinical signs included ataxia, cachexia, inactivity, paresis, paraparesis
, bladder atony, tremors, hypothermia, lethargy, constipation, paralysis, a
nd anorexia. Two rabid ferrets manifested aggressive behavior. Mean morbidi
ty period was 4 to 5 days (range, 1 to 8 days). Virus antigen was detected
in brain tissue from all rabid ferrets (n = 19). Two rabid ferrets had dete
ctable virus-neutralizing antibody. Of 32 ferrets that survived, only 1 ser
oconverted; survivors remained clinically normal throughout the observation
period. Babies virus was isolated from salivary glands of 12 of 19 (63%) r
abid ferrets, and 9 (47%) shed virus in saliva. Initiation of virus excreti
on ranged from 2 days before onset of illness to 6 days after onset.
Conclusions and Clinical Relevance-Babies should be considered in the diffe
rential diagnosis for ferrets that have acute onset of paralysis or behavio
ral changes and a condition that rapidly deteriorates despite intense medic
al intervention.