The Emergence of SARS-CoV-2 within the Dog Population in Croatia: Host Factors and Clinical Outcome

Abstract

Over a year into the COVID-19 pandemic, there is growing evidence that SARS-CoV-2 infections among dogs are more common than previously thought. In this study, the prevalence of SARS-CoV-2 antibodies was investigated in two dog populations. The first group was comprised of 1069 dogs admitted to the Veterinary Teaching Hospital for any given reason. The second group included dogs that shared households with confirmed COVID-19 cases in humans. This study group numbered 78 dogs. In COVID-19 infected households, 43.9% tested ELISA positive, and neutralising antibodies were detected in 25.64% of dogs. Those data are comparable with the secondary attack rate in the human population. With 14.69% of dogs in the general population testing ELISA positive, there was a surge of SARS-CoV-2 infections within the dog population amid the second wave of the pandemic. Noticeably seroprevalence of SARS-CoV-2 in the dog and the human population did not differ at the end of the study period. Male sex, breed and age were identified as significant risk factors. This study gives strong evidence that while acute dog infections are mostly asymptomatic, they can pose a significant risk to dog health. Due to the retrospective nature of this study, samples for viral isolation and PCR were unavailable. Still, seropositive dogs had a 1.97 times greater risk for developing central nervous symptoms.

Susceptibility of Pets to SARS-CoV-2 Infection: Lessons from a Seroepidemiologic Survey of Cats and Dogs in Portugal

“…Cats and dogs have been exposed to SARS-CoV-2, involving the detection of SARS-CoV-2 RNA in respiratory and/or fecal specimens [9][10][11][12][13], as well as specific SARS-CoV-2 antibodies [14][15][16][17][18][19][20][21][22][23][24][25][26][27][28]. According to experimental studies, dogs have little susceptibility to infection [29,30] in contrast with cats, who exhibited higher viral shedding, respiratory pathology, and efficient transmission of SARS-CoV-2 within cats by respiratory droplets [29][30][31][32].…”

Near-Complete Genome of SARS-CoV-2 Delta (AY.3) Variant Identified in a Dog in Kansas, USA

“…Markedly, animals infected with the delta variant shed virus for up to 14 days post infection, four days longer than other strains [ 25 ]. Serological studies have detected circulating SARS-CoV-2 antibodies in canines, including in 43.9% of dogs in Croatia as well as a single dog in Italy [ 27 , 28 ]. Furthermore, molecular detection and sequencing identified an alpha variant (B.1.1.7) virus from an asymptomatic dog in Spain [ 29 ].…”

Report of One-Year Prospective Surveillance of SARS-CoV-2 in Dogs and Cats in France with Various Exposure Risks: Confirmation of a Low Prevalence of Shedding, Detection and Complete Sequencing of an Alpha Variant in a Cat

“…Importantly, those cat-to-cat transmissions were possible even between asymptomatic cats [11]. There are more than 100 million cats and 90 million dogs in Europe [12], with a relatively high seroprevalence revealed by a rate of seroconversion starting from 0.2% and reaching 14.69% in the general companion animal population, and reaching from 21-53% in those living in SARS-CoV-2-infected households [6,[13][14][15][16][17][18][19][20][21]. Altogether, these observations led us to consider that the role of pets, albeit limited in the global SARS-CoV-2 epidemiology, might be more significant when humans come in close contact with animals living in SARS-CoV-2-positive households.…”