Serological investigation of zoo animals: SARS-CoV-2 antibodies detected in a European moose and an Asian golden cat.

As the human COVID-19 pandemic progressed, the causative agent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was detected in an increasing number of animal species, raising concerns about the establishment of new animal reservoirs. Here, we investigated the presence of SARS-CoV-2 antibodies in serum samples of 123 mammals housed in various zoological institutions in Germany with direct or indirect contact to humans (visitors and zoo staff), collected between December 2019 and January 2025. The animals included diverse representatives from the orders Artiodactyla (n = 59), Carnivora (n = 54), as well as Proboscidea (n = 7), two perissodactyls, and a rodent. All serum samples were tested using a species-independent commercial surrogate virus neutralization test (sVNT) and a multispecies receptor-binding domain (RBD)-based ELISA. With two exceptions, all samples tested consistently negative in both assays. However, antibodies against SARS-CoV-2 were detected in a European moose (Alces alces) and an Asian golden cat (Catopuma temminckii), sampled in 2020 and 2021, respectively, expanding the known host range of SARS-CoV-2. Hence, pathogen monitoring and continued health surveillance in both captive and wild animal populations are essential for understanding the actual host range, potential reservoir formation, and the broader implications for animal and public health.