Panthera tigris (Felidae) tigers and COVID-19

I got many questions about the report of a tiger in the Bronx zoo with COVID-19.  I will confess I was intrigued but also a bit impatient that it took over the media for a day. We do not want to get too distracted by outliers in a pandemic and not keep our eyes on the ball. 

Yet, wait, maybe tigers with COVID-19 is a part of the center of the story because COVID-19 is a “spillover” event. It is another example of the interconnections of this living world and the notion of “One Health”.   One Health is the frontier of public health and is an ecological vision of health that includes animals, humans, and the environment.  Throughout the last few decades, diseases that spill over from animals to humans have been on the rise.  Most of the notable pandemics started as spillover events including HIV/AIDS, Ebola, avian influenza, and now COVID-19.

I went to one of my favorite One Health experts Vanessa Grunkemeyer DVM MPH faculty at University of New Hampshire and I asked about the tiger and the story and here is what she said.

“Yes, the tigers have gotten a lot of press and are causing quite a buzz even in the vet community. Unfortunately, the data on non-human animals and COVID-19 is sparse and evolving every day (so much about this disease is). One of clearest write-ups I have seen about the tigers came through promed (I included it below) from the zoo vet who oversees these animals. The American Veterinary Medical Association (AVMA) is keeping up to date and posting great information for animal owners/general public on their website (   However, I particularly love the updates by Dr. Scott Weese a public health vet from Canada, on his Worms and Germs blog (

The most notable things about the tiger seems to be that this cat was symptomatic, which has not been true of most if not all of the other cases where virus has been isolated from non-human animals.

Previous to this a very small number of companion animals who lived with COVID-19 positive humans had “tested positive” for the virus; some of these were PCR tests and at least 1 was virus isolation.  I believe 1 of the cats in Europe did seroconvert.

We have every suspicion that animals can act as mechanical vectors for the virus and their leashes, collars, etc. could act as fomites (inanimate objects that can transfer pathogens—like a doorknob). Thus, appropriate precautions should be taken when these animals are kept in contact with known or potentially positive humans -Vanessa “

For those readers that really want to follow this topic one level deeper I have included a few of the posts from ProMed with more specific information that Vanessa sent and I include some of the links.

   1. PRO/AH/EDR> COVID-19 update (84): USA, tigers
   2. PRO/AH/EDR> COVID-19 update (85): USA (NY) tiger, OIE
   3. PRO/PL> Begomoviruses, basil – Uganda: new pathogens

A ProMED-mail post
ProMED-mail is a program of the
International Society for Infectious Diseases

Date: Mon 6 Apr 2020
From: Dr. Paul P. Calle [edited]

On [Fri 3 Apr 2020], qPCR testing for SARS-Coronavirus-2 (SARS-CoV-2)
on duplicate nasal and oropharyngeal swabs and tracheal wash samples
from a 4-year-old female Malayan tiger (_Panthera tigris jacksoni_)
with respiratory signs living at the Wildlife Conservation Society’s
(WCS) Bronx Zoo was performed at the Animal Health Diagnostic Center
and New York State Veterinary Diagnostic Laboratory at Cornell
University College of Veterinary Medicine and the University of
Illinois College of Veterinary Medicine Veterinary Diagnostic
Laboratory. The swabs yielded presumptive positive results that were
confirmed by the USDA National Veterinary Services Laboratory on [Sat
4 Apr 2020].

The index case was one of 2 Malayan tigers, 2 Amur tigers (_Panthera
tigris altaica_), and 3 African lions (_Panthera leo_) that developed
respiratory signs over the course of a week characterized by a dry
cough and in some cases wheezing, but no dyspnea or nasal or ocular
discharge. Mild anorexia was noted in some cases. All of the cats are
long term residents of the zoo, do not have chronic medical
conditions, and there have been no new animal introductions to these
groups for several years.

All other Amur and Malayan tigers, snow leopard (_Panthera uncia_),
cheetah (_Acinonyx jubatus_), clouded leopard (_Neofelis nebulosa_),
Amur leopard (_Panthera pardus orientalis_), puma (_Puma concolor_),
and serval (_Leptailurus serval_) at the Bronx Zoo remain healthy
without evidence of clinical illness.

The source of infection is presumed to be transmission from a keeper
who, at the time of exposure, was asymptomatically infected with the
virus or before that person developed symptoms [i.e., presymptomatic].
The cats have received antibiotics and supportive care as needed, and
all of the affected cats are doing well with no worsening of their
clinical signs and daily gradual improvement. Enhanced PPE [surgical
masks (not N95 masks), face shields, gloves, coveralls] use has been
implemented for staff caring for all non-domestic felids in the 4 WCS

SARS-CoV-2 is a World Organization for Animal Health (OIE) reportable
disease with country-specific mandatory reporting requirements by
national governments of positive results, and national and
international veterinary and public health agency notifications. We
will provide more technical details and answer questions as we can,
but as I’m sure you can imagine it is quite challenging right now to
keep up with everything that is going on. We will also be publishing
this information in peer-reviewed scientific venues.

Paul P. Calle, VMD Diplomate ACZM & ECZM (Zoo Health Management)
WCS Vice President for Health Programs
Chief Veterinarian Director,
Zoological Health Program Wildlife Conservation Society

By the end of March, the cat of a woman with COVID-19 tested positive
in Belgium (see post#
This cat presented clinical signs: diarrhea, vomiting and difficulty
breathing. A few days later, a cat in Hong Kong, owned by a COVID-19
infected patient, also tested positive (post#, although in this case no
clinical signs were detected.

A recent experiment carried out in China, so far published as a
(<>), found
that cats and ferrets exposed by SARS-CoV-2 by intranasal inoculation
develop active infection, replicating efficiently. Moreover, in cats
it was shown that the virus can be transmitted via droplets, as
sentinel cats housed next to infected ones also became infected. Dogs,
pigs and birds, on the contrary, proved to be poor hosts, with limited
replication (although it is noteworthy that 2 dogs became infected
from their owners in Hong Kong).

Cats are in the _Felidae_ family, and so are cougars, lions, tigers,
jaguars, and all the other wild felids. This report in tigers and the
other observations and experimental results alert us to the fact that
felids (and maybe also mustelids) may become infected by SARS-CoV-2.
The significance of this is yet to be established (conservation
concern?; source of transmission for humans?; role in propagation?).
In the meantime, cautionary measures should be taken so that domestic
and wild animals are not exposed to patients with COVID-19. – Mod.PMB

A ProMED-mail post
ProMED-mail is a program of the
International Society for Infectious Diseases

Information received on [and dated] 6 Apr 2020 from Dr. from Dr Mark
Davidson, associate administrator, USDA-APHIS, United States
Department of Agriculture, Washington, United States of America

Source of the outbreak(s) or origin of infection: suspected human

Epidemiological comments: 5 tigers and 3 lions were housed in 2
enclosures at a zoo. The 1st tiger showed clinical signs of disease on
[27 Mar 2020]. By [3 Apr 2020], 3 additional tigers and all lions were
showing clinical signs. Clinical signs consisted of a dry cough and
some wheezing; one animal had inappetence. None of the animals were in
respiratory distress. The lions and tigers were isolated and no other
animals at the zoo have shown any signs of respiratory disease.
Samples were collected from the 1st affected tiger and it was
confirmed positive for SAR-CoV-2/COVID-19. The other animals with
clinical signs are also presumed to be infected. All animals are
stable and are recovering. It is assumed that an asymptomatic zoo
employee infected the animals.

Control measures
Measures applied: quarantine; disinfection; vaccination permitted (if
a vaccine exists), no treatment of affected animals
Measures to be applied: no other measures

–[See Also:
COVID-19 update (76): China (HU) animal, cat, owned, stray,
COVID-19 update (75): China (Hong Kong) cat, OIE
COVID-19 update (70): China (Hong Kong) cat, pets & stock
COVID-19 update (58): Belgium, cat, clinical case, RFI
COVID-19 update (57): global, re-using PPE, DR Congo, more countries,
COVID-19 update (56): China (Hong Kong) animal, dog, final serology
COVID-19 update (45): China (Hong Kong) animal, dog, 2nd case PCR
COVID-19 update (37): China (Hong Kong) animal, dog, prelim. serology
COVID-19 update (30): China (Hong Kong) dog, susp, serology pending
COVID-19 update (25): China (Hong Kong) dog, susp, OIE
COVID-19 update (22): companion animals, dog susp, RFI
COVID-19 update (17): China, animal reservoir, wildlife trade &
COVID-19 update (11): animal reservoir, intermediate hosts, pangolin
COVID-19 update (08): companion animals, RFI
COVID-19 update (06): animal reservoir, intermediate hosts
Novel coronavirus (42): China, global, COVID-19, SARS-CoV-2, WHO
Novel coronavirus (40): animal reservoir, pangolin poss intermediate
host, RFI
Novel coronavirus (28): China (HU) animal reservoir
Novel coronavirus (22): reservoir suggested, bats
Novel coronavirus (20): China, wildlife trade ban
Novel coronavirus (18): China (HU) animal reservoir
Novel coronavirus (15): China (HU) wild animal sources
Novel coronavirus (03): China (HU) animal reservoir suggested, RFI
Novel coronavirus (01): China (HU) WHO, phylogenetic tree
Undiagnosed pneumonia – China (HU) (07): official confirmation of
novel coronavirus]

Published by sharon Mcdonnell

Medical Epidemiologist and Community Memeber

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