Title : Influenza viruses: Detection in domestic animals, Thailand
Respiratory virus infections in domestic animals are a significant issue for the veterinary, livestock industries and public health. Influenza is one of the major viral diseases that affect humans and animals. With the limited report of the animal influenza virus epidemic in Thailand, this study aimed to determine the presence of the influenza virus in domestic animals with respiratory signs by nasal swab collection in a tropical environment. A cross-sectional study was conducted from June 2020 to August 2021 in Chiang Mai province, Thailand. Nasal swab samples from 96 animals (pigs, dogs, cats and dairy calves) were tested for influenza A virus (IAV) and 168 animals (dairy calves) were tested for influenza C virus (ICV) and influenza D virus (IDV) by using real-time rt-PCR. The respiratory signs and general data of all animals were recorded on the sample collection date. Low percentages of IAV at 4.3%, 0%, and 4.4% were found in cats, dogs, and dairy calves with respiratory clinical signs, respectively, but IAV in pigs with the clinical signs was high at 15%. The respiratory disease pigs with mucous discharge were associated with IAV at p < 0.05. The percentages of ICV, and IDV in dairy calves were 68.4%, and 65.8%, respectively. The occurrence of influenza D virus had a significant rate of coinfection with ICV (p < 0.01). In conclusion, influenza virus was found in most domestic animals in a tropical environment which might relate to the cross-species transmission in this area. Routine monitoring of influenza virus infections in domestic animals should be conducted.