[Show abstract][Hide abstract] ABSTRACT: The avian origin canine influenza virus H3N2 has been recently isolated and found to be currently in dog population in South Korea and China. The purpose of this study was to clarify the relationship between immunosuppressive glucocorticoids used in veterinary clinical practice and viral shedding pattern of influenza in dogs.
Eight conventional beagle dogs were divided into control infection group and immunocompromised group. Dogs of both groups were infected with H3N2 canine influenza virus (2×10(6.0) EID50/0.1 mL). Dogs in immunocompromised group were given orally 3.0 mg/kg prednisolone for 7 days. Virus shedding was monitored using real-time polymerase chain reaction. After necropsy, histopathologic lesions were compared.
We found that immunocompromised dogs exhibited more prolonged (8 days vs. 13 days) and higher magnitude viral shedding than control group (peak titer of viral shedding 4.6 vs. 5.5 EID50).
Restricted use of immunosuppressive drugs in the clinical setting might help control the rapid spread of H3N2 through local dog populations.
Clinical and experimental vaccine research. 01/2013; 2(1):66-8.
[Show abstract][Hide abstract] ABSTRACT: Avian origin canine influenza virus was reported in Korea. The dog to dog contact transmission of the avian origin canine influenza virus (CIV) H3N2 and CIV H3N8 was shown by experimental contact transmission. This study was focused on viral excretion and fever in order to elucidate the epidemiological associations which might be helpful to control the disease transmissions in CIV outbreak in dogs.
An influenza seronegative 10-week-old Beagle dog was experimentally inoculated with the canine influenza virus A/canine/01/2007, subtype H3N2. Eight hours after inoculation, the infected dog was cohoused with seven uninfected Beagle dogs. Clinical signs including fever were recorded for 14 days post inoculation.
The infected dog and four of seven contact dogs in the study showed clinical signs (sneezing, nasal discharge and coughing) during the study. Viral shedding occurred in all of the animals tested and began on 1 to 6 DPI in dogs with clinical signs. Elevated body temperatures above 39.5 °C (geometric mean temperature of 39.86 °C ± 0.49) were observed in all symptomatic dogs. The mean viral titer during fever was 2.99 log EID₅₀/ml, which was significantly higher than the viral titer detected in the non fever.
The data show that contact dogs with a canine influenza infected dog shed different levels of virus in their nasal excretions and demonstrate that clinical signs, including fever, significantly correlate with the viral shedding.
[Show abstract][Hide abstract] ABSTRACT: Transmission of avian-origin influenza A virus (H3N2) to dogs had been reported and since then the H3N2 virus infection across South Korea has been occurred repeatedly in the country's animal clinics and kennels. Dog-to-dog transmission of the virus had also been experimentally demonstrated by direct contact. In this study, immunogenicity and protective efficacy against challenge exposure of the formalin-inactivated H3N2 influenza virus vaccine with a synthetic polymer adjuvant was investigated in dogs. The beagle puppies received two inactivated vaccine injections intramuscularly 2 weeks apart. Serological investigation by a hemagglutination inhibition (HI) test and an ELISA assay indicated that a significant increase in antibody titer was displayed 2 weeks after the second vaccination. Clinical signs, virus shedding and histopathological lesions in the lungs were exhibited in unvaccinated beagle puppies directly challenged through an intranasal route with the virus 2 weeks after the second vaccination. However, the vaccinated animals did not show any clinical signs and showed milder pathological lung lesions and shorter shedding duration with lower loads than controls'. These results indicated that the synthetic polymer-adjuvant avian-origin canine influenza virus (CIV) vaccine had produced antibody response and protection from avian-origin CIV challenge in dogs.