raw data for 'Cats are More Susceptible to the Prevalent H3 Subtype Influenza Viruses than Dogs'

Materials and methodsVirusesThe following influenza viral strains were used in this study: H3N2 AIV (A/duck/Guangdong/W12/2011) (Accession Number: JX175250.1); H3N8 AIV (A/Gallinula/Guangzhou/A1/2017) (Accession Number: ON287054.1); H3N2 SIV (A/Swine/Guangdong/FS4/2015) (GISAID isolate-ID: EPI_ISL_249845); H3N2 CIV (A/canine/Guangdong/1/2006) (Accession Number: GU433351.1). The viral titers were evaluated by EID50/ml assay. Virus stocks were propagated in 9- to 12-day-old embryonated specific pathogen-free (SPF) chicken eggs and titrated using the EID50 assay.Animals and groupingSixteen 9- to 11-week-old beagles and sixteen 9- to 12-week-old domestic shorthair cats, all seronegative for influenza A viruses, were used in this study. Animals were randomly divided into five groups for both beagles and shorthair cats separately: three experimental groups and two control groups. Each experimental group consisted of four animals, and each control group consisted of two animals. All animals were anesthetized with propofol (1-2.5 mg/kg) and intranasally inoculated with 10⁶ EID50 of the corresponding virus in 1.0 mL PBS. Control groups were inoculated with 1.0 mL pathogen-free SPF chicken embryo allantoic liquid.Clinical signs and seroconversionClinical signs and rectal temperature were monitored daily for 14 days post-inoculation (dpi). Nasal swabs were collected daily from 1 to 14 dpi and titrated by EID50 assay in SPF chicken eggs. Blood samples were collected at 0, 3, 5, 7, 14, and 21 dpi for serological antibodies assessment, treated with receptor-destroying enzyme (RDE), and subjected to hemagglutination inhibition (HI) assay.Viral replication and pathological examinationAt 4 dpi, one animal from each group was euthanized with an intravenous injection of pentobarbital sodium (150-200 mg/kg). Lung, trachea, nasal turbinate, heart, liver, spleen, kidney, intestine, stomach, and brain tissues were collected. In consideration of animal welfare, euthanasia was performed on only one animal per group in this study, and three tissue samples were collected from each type of tissue. Tissues were fixed in 10% neutral buffered formalin, processed for hematoxylin and eosin (H&E) staining, and immunohistochemistry (IHC). All tissues were weighed and homogenized in 1 mL of PBS per gram, then centrifuged to obtain the supernatant, which was titrated using the EID50 assay to assess viral replication.Ethics statementAll procedures in animal experiments met the requirements of animal welfare and were approved by the Experimental Animal Welfare Ethics Committee of South China Agricultural University (protocol code: 2024c016). All experimental animals were monitored by university-licensed veterinarians. All animal experiments were performed in a level 2 animal biosafety laboratory (A-BSL level 2).