Evaluation of the Transmission Potential and Infectivity of H9n2 Avian Influenza Virus in Dogs Fed Infected Chicken Carcasses

Despite the frequent reports of avian influenza A virus infections in dogs and cats, which have attracted the attention of veterinary practitioners and scientists in the respective fields of virology and epidemiology during the last decade, few reports are available regarding the natural exposure of dogs to low pathogenic viruses in field conditions. This may be important in the epidemiology of viruses in dogs on chicken farms. One of the possible causes of the interspecies transmission of viruses may be the consumption of infected carcasses by dogs. This hypothesis was examined by feeding dogs with experimentally H9N2 infected chicks. To this end, 8 dogs were selected and divided into two groups: test (n=5) and control (n=3). The dogs were fed commercial and standard diets during a 3-week adaptation period and from day 4 to 10 after being fed chicken carcasses. The test group was given H9N2 infected chicken carcasses, whereas the control group was fed on healthy ones from days 1 to 3 of the experiment. Clinical signs including depression, sneezing, coughing, nasal and ocular discharge, respiratory and heart rate changes, and rectal temperature, were monitored daily from day 0 to 10. Faeces and nasal swabs were collected on a daily basis for virus detection via RT-PCR during the experimental period. HI tests for antibody titre measurement were also performed on each day of the experimental period. The results of the study indicated that the aforementioned clinical parameters remained normal in both the test and control groups. No signs of viruses were detected in the nasal swab and faeces of dogs in both groups. HI test results showed no considerable antibody titer against the H9N2 virus in either group. In conclusion, it seemed unlikely that the consumption of H9N2 infected chicken carcasses by dogs could be a cause of infection in dogs.