Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is the cause of Coronavirus Disease 2019 (COVID-19) and responsible for the current pandemic. Recent SARS-CoV-2 susceptibility and transmission studies in cats show that the virus can replicate in these companion animals and transmit to other cats. Here, we present an in-depth study of SARS-CoV-2 infection, associated disease and transmission dynamics in domestic cats. Six 4- to 5-month-old cats were challenged with SARS-CoV-2 via intranasal and oral routes simultaneously. One day post challenge (DPC), two sentinel contact cats were co-mingled with the principal infected animals. Animals were monitored for clinical signs, clinicopathological abnormalities and viral shedding throughout the 21 DPC observation period. Postmortem examinations were performed at 4, 7 and 21 DPC to investigate disease progression. Viral RNA was not detected in blood but transiently in nasal, oropharyngeal and rectal swabs and bronchoalveolar lavage fluid as well as various tissues. Tracheobronchoadenitis of submucosal glands with the presence of viral RNA and antigen was observed in airways of the infected cats on 4 and 7 DPC. Serology showed that both, principal and sentinel cats, developed SARS-CoV-2-specific and neutralizing antibodies to SARS-CoV-2 detectable at 7 DPC or 10 DPC, respectively. All animals were clinically asymptomatic during the course of the study and capable of transmitting SARS-CoV-2 to sentinels within 2 days of comingling. The results of this study are critical for our understanding of the clinical course of SARS-CoV-2 in a naturally susceptible host species, and for risk assessment of the maintenance of SARS-CoV-2 in felines and transmission to other animals and humans.

中文翻译：

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家猫的SARS-CoV-2感染，疾病和传播

严重急性呼吸系统综合症冠状病毒2（SARS-CoV-2）是2019年冠状病毒病（COVID-19）的病因，是当前大流行的原因。最近对猫的SARS-CoV-2敏感性和传播研究表明，该病毒可以在这些伴侣动物中复制并传播给其他猫。在这里，我们目前对家猫的SARS-CoV-2感染，相关疾病和传播动力学进行了深入研究。六只4至5个月大的猫同时通过鼻内和口服途径接受SARS-CoV-2攻击。攻击后一天（DPC），将两只前哨接触猫与主要感染动物混在一起。在整个21个DPC观察期内，对动物进行临床体征，临床病理异常和病毒脱落的监测。死后检查在4点进行 7和21 DPC调查疾病进展。在血液中未检测到病毒RNA，但在鼻，口咽和直肠拭子，支气管肺泡灌洗液以及各种组织中均检测到了病毒RNA。在感染的猫的气道上，在4和7 DPC上观察到了粘膜下腺的气管支气管腺炎，其中存在病毒RNA和抗原。血清学表明，主要猫和前哨猫都分别形成了SARS-CoV-2特异性和中和性抗体，可分别在7 DPC或10 DPC检测到。在研究过程中，所有动物在临床上均无症状，并且能够在合并后的两天内将SARS-CoV-2传播至前哨。这项研究的结果对于我们理解SARS-CoV-2在自然易感宿主物种中的临床过程至关重要，