Funding for this research was provided by:
National Natural Science Foundation of China (81702008, 31700159)
Key discipline construction of colleges and universities in Hebei Province (Ji Jiao Gao No. 4)
Received: 22 February 2020
Accepted: 15 July 2020
First Online: 22 July 2020
Ethics approval and consent to participate
: All blood samples were collected under the permission from the owners of the pet dogs, and performed according to Guidance for Experimental Animal Welfare and Ethical Treatment by the Ministry of Science and Technology of China (ExternalRef removed). This study was approved by the Scientific Ethic Committee of Chengde Medical University (number 2017020).
: Not applicable.
: The authors declare that they have no competing interests.