Abstract
The clinical effects of recombinant feline interferon-ω (rFeIFN-ω), produced in silkworm by recombinant baculovirus, were examined in 3-4 month-old beagle dogs given an experimental canine parvovirus type-2 (CPV-2) infection. Clinical symptoms, such as pyrexia, vomiting, anorexia and diarrhea, were observed on day 4 after oral inoculation of 107 TCID 50 of CPV-2 (cc 238 strain) in almost all the inoculated dogs. From day 4, rFeIFN-ω (1 mega units/kg/day) or physiological saline was administered intravenously to infected dogs for 3 consecutive days. Seven out of 17 dogs treated with physiological saline showed hemorrhagic diarrhea and continuously expressed severe clinical enteritis; one dog died with a large amount of hemorrhagic rice-water stool on day 6 after viral exposure. In contrast, 4 out of 12 dogs treated with rFeIFN-ω showed severe clinical enteritis associated with intermittent diarrhea. Scoring of fecal condition revealed that treatment with rFeIFN-ω significantly shifted the enteritis from a severe to mild form. Furthermore, rFeIFN-ω administered in the morning decreased the number of dogs expressing clinical enteritis in the evening suggesting a rapid effect. Vomiting and anorexia were also improved by treatment with rFeIFN-ω. These results suggest that rFeIFN-ω can reduce severe enteritis caused by CPV-2 infection in dogs.
