2.1 History, clinical examination, hematology and serum
biochemistry
This study is focused on the clinical and laboratory investigation of 3
European Shorthaired cats, which were residing exclusively indoors with
their owner, a veterinary medicine undergraduate student affected by
COVID-19. The owner lives by herself, in the city of Thessaloniki
(Central Macedonia, Northern Greece) in a 40 m2 flat
in an apartment block. Owner’s signs of worsening fatigue and intense
sneezing first appeared on November 12th 2020 (day 0;
D0), followed by anosmia and loss of taste two days later (D2). On D4
the owner was diagnosed with COVID-19 after being subjected to a rapid
SARS-CoV-2 antigen test, followed by real-time RT-PCR. Since the onset
of clinical signs, the owner was quarantined at home, according to the
guidelines issued by the National Public Health Organization of Greece
(EODY). The duration of the owner’s clinical signs was one week,
followed by complete recovery. During the entire period (i.e. before the
onset of signs and far beyond the time of apparent clinical recovery),
the owner remained in close contact with all cats, sharing with them all
the apartment’s rooms, including the bedroom. The interaction pattern
between the owner and each cat was similar (i.e. petting, giving kisses
or licks) and did not change, even after the molecular confirmation of
the SARS-CoV-2 infection of the owner.
One day after the confirmation of the diagnosis (D5), one of the cats,
an 11-year-old neutered female (Cat #1; C1) showed mild signs of
self-limiting diarrhea for 3 days, without exhibiting any other
symptoms. Given the COVID-19 infection status of the owner, this cat, as
well as the other two (Cat #2; C2: a 10-year-old neutered male and Cat
#3; C3: a 10-year-old neutered female) that were living in the same
environment and did not experience clinical signs were subjected to
clinical examination and laboratory investigations for SARS-CoV-2
infection.
On D16, all cats were clinically evaluated in detail in their household
environment, and blood samples were obtained for hematology and serum
biochemistry. Complete blood counts (ADVIA® 120 hematology system;
Siemens Healthcare Diagnostics, Eschborn, Germany), including 100-cell
manual differential leukocyte counts and evaluation for platelet
aggregates, along with comprehensive blood serum biochemistry analysis
(Vitalab Flexor E, Vital Scientific N.V., Spankeren/Dieren, The
Netherlands) were performed for each cat.