Abstract:
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections in nondomestic felids
have been documented in North America, South America, Africa, Europe, and Asia. Between March 2020 and
February 2021, at nine institutions across three continents, infection was confirmed in 16 tigers (Panthera tigris),
14 lions (Panthera leo), three snow leopards (Panthera uncia), one cougar (Puma concolor), and one Amur leopard
cat (Prionailurus bengalensis euptilurus) ranging from 2 to 21 yr old (average, 10 yr). Infection was suspected in an
additional 12 tigers, 4 lions, and 9 cougars. Clinical signs (in order of most to least common) included coughing,
ocular and/or nasal discharge, wheezing, sneezing, decreased appetite, lethargy, diarrhea, and vomiting.
Most felids recovered uneventfully, but one geriatric tiger with comorbidities developed severe dyspnea and
neurologic signs necessitating euthanasia. Clinical signs lasted 1–19 d (average, 8 d); one tiger was asymptomatic.
Infection was confirmed by various methods, including antigen tests and/or polymerase chain reaction
(PCR) of nasal or oral swabs, tracheal wash, and feces, or virus isolation from feces or tracheal wash. Infection
status and resolution were determined by testing nasal swabs from awake animals, fecal PCR, and observation
of clinical signs. Shedding of fecal viral RNA was significantly longer than duration of clinical signs. Postinfection
seropositivity was confirmed by four institutions including 11 felids (5 lions, 6 tigers). In most instances,
asymptomatic or presymptomatic keepers were the presumed or confirmed source of infection, although in
some instances the infection source remains uncertain. Almost all infections occurred despite using cloth facemasks
and disposable gloves when in proximity to the felids and during food preparation. Although transmission
may have occurred during momentary lapses in personal protective equipment compliance, it seems
probable that cloth masks are insufficient at preventing transmission of SARS-CoV-2 from humans to nondomestic
felids. Surgical or higher grade masks may be warranted when working with nondomestic felids.
