2.1 Ethics statement
This study was performed according to the animal welfare guidelines of
the World Organization for Animal Health, and animal sampling was
strictly carried out in accordance with guidelines established by the
Ethics of Animal Experiments of Northwest A&F University, Yangling,
China. All protocols were approved by this committee (Permit Number:
2014BAD23B11). The field study did not include endangered or protected
species. No specific permissions were required for the collection of
samples because the samples were collected from public areas or
non-protected areas.
2.2 Sample
collection
In total, 571 serum samples were collected from healthy pigeons from 39
racing pigeon clubs between November 2016 and August 2019 in 11
provinces or municipalities of China, including Beijing, Hebei,
Liaoning, Shanxi, Gansu, Qinghai, Shandong, Shaanxi, Xinjiang Uygur
Autonomous Region, Ningxia Hui Autonomous Region and Inner Mongolia
Autonomous Region. Moreover, 51 fatally diseased racing pigeons from 7
racing pigeon clubs in 5 provinces or municipalities were submitted to
our laboratory at College of Veterinary Medicine, Northwest A&F
University to determine the pathogen of the disease. The 0.2 g sections
of internal organs (the heart, liver, spleen, lung, and intestine) were
obtained during the postmortem examination of all mentioned dead
pigeons. All samples were stored at −80°C before DNA extraction.