In human beings, there are five reported variants of concern of severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2). However, in contrast to human beings, descriptions of infections of animals with specific variants are still rare. The aim of this study is to systematically investigate SARS-CoV-2 infections in companion animals in close contact with SARS-CoV-2-positive owners (“COVID-19 households”) with a focus on the Delta variant. Samples, obtained from companion animals and their owners were analyzed using a real-time reverse transcriptase-polymerase chain reaction (RT-qPCR) and next-generation sequencing (NGS). Animals were also tested for antibodies and neutralizing activity against SARS-CoV-2. Eleven cats and three dogs in nine COVID-19-positive households were RT-qPCR and/or serologically positive for the SARS-CoV-2 Delta variant. For seven animals, the genetic sequence could be determined. The animals were infected by one of the pangolin lineages B.1.617.2, AY.4, AY.43 and AY.129 and between zero and three single-nucleotide polymorphisms (SNPs) were detected between the viral genomes of animals and their owners, indicating within-household transmission between animal and owner and in multi-pet households also between the animals. NGS data identified SNPs that occur at a higher frequency in the viral sequences of companion animals than in viral sequences of humans, as well as SNPs, which were exclusively found in the animals investigated in the current study and not in their owners. In conclusion, our study is the first to describe the SARS-CoV-2 Delta variant transmission to animals in Switzerland and provides the first-ever description of Delta-variant pangolin lineages AY.129 and AY.4 in animals. Our results reinforce the need of a One Health approach in the monitoring of SARS-CoV-2 in animals.

SARS-CoV-2 Seroprevalence in Cats, UK

Mirrors can enrich the environment of some social animals kept in isolation. In this study, the effect of mirrors on the behaviour of isolated, or partially isolated, caged rabbits was tested. In a changeover experiment, four treatments were investigated: isolated without mirrors; partially isolated (with a conspecific housed behind a partition) without mirrors; isolated with mirrors; and partially isolated with mirrors. Behaviour was recorded during the first hour for which the rabbits were in the cages with the stimuli, and then again after one week. Initially, the rabbits' alertness increased, which may be because they perceived the mirror image to be a potential threat. The mirrors also stimulated investigation by the rabbits, which initially scraped them rapidly with their forepaws (scrabbling) and sniffed them. Although sniffing was maintained until the end of the week, scrabbling was not, probably because the rabbits failed to elicit the normal reactions of a conspecific from their mirror images. Mirrors also reduced the time rabbits spent sitting in their living area looking out of the cage, and increased their behavioural complexity, as determined from the number of behaviours performed per minute. In a second experiment, the responses of seven rabbits to four stimuli were recorded: a conspecific; a toy animal; a mirror; and a blank card. The rabbits were presented with pairs of stimuli at either end of a marked board. The responses of the rabbits to mirrors were more similar to their responses to a blank card or to a soft toy than to a conspecific. Although the rabbits did not respond to mirror images as if they were conspecifics, the mirrors may have had benefits to the complexity of behaviour of rabbits in small cages.

Background: Bovine papillomavirus types 1 and 2 (BPV1 and BPV2) are accepted aetiological agents of equine sarcoids. Recently, genetically similar BPV13 has been identified from equine sarcoids in Brazil. Objectives: To determine whether BPV13 DNA can be also found in sarcoid‐affected horses in Austria, and donkeys in Northern Italy and the UK, and should hence be considered in the context of vaccine‐mediated sarcoid prevention. Study design: Cross sectional study. Methods: A total of 194 archival, equine and asinine DNA isolates derived from confirmedly delta‐BPV‐positive tumours were subjected to quality control by photometric analysis and equine beta‐actin PCR. Isolates with DNA concentrations >0.9 ng/µl and confirmed PCR‐compatibility (n = 135) were subsequently screened for the presence of BPV13 DNA using BPV13‐specific PCR primers for amplification of a 771 bp region comprising the BPV13 E5 gene. Results: BPV13 E5 PCR scored negative for all 135 samples. Included positive, negative and no‐template controls yielded anticipated results, thus confirming reliability of obtained data. Main limitations: Moderate number of tested tumour DNA extracts (n = 135; equivalent to 127 tumour‐affected equids). Conclusions: Despite its moderate size, the sample was considered representative enough to suggest a low occurrence of BPV13 in Austria, as it randomly comprised equine patients of different breed, age, gender, and European provenience. BPV13 was not associated with tested sarcoids in rescued donkeys originating from several other European countries. Large‐scale BPV13 screenings are necessary to allow for a more precise estimation of the prevalence and distribution of BPV13 infections in European equids suffering from sarcoid disease.

Throughout the COVID-19 pandemic, SARS-CoV-2 infections in domestic cats have caused concern for both animal health and the potential for inter-species transmission. Cats are known to be susceptible to the Omicron variant and its descendants, however, the feline immune response to these variants is not well defined. We aimed to estimate the current seroprevalence of SARS-CoV-2 in UK pet cats, as well as characterise the neutralising antibody response to the Omicron (BA.1) variant. A neutralising seroprevalence of 4.4% and an overall seroprevalence of 13.9% was observed. Both purebred and male cats were found to have the highest levels of seroprevalence, as well as cats aged between two and five years. The Omicron variant was found to have a lower immunogenicity in cats than the B.1, Alpha and Delta variants, which reflects previous reports of immune and vaccine evasion in humans. These results further underline the importance of surveillance of SARS-CoV-2 infections in UK cats as the virus continues to evolve.

A higher prevalence of SARS-CoV-2 infections in animals that have close contact with SARS-CoV-2-positive humans (“COVID-19 households”) has been demonstrated in several countries. This prospective study aimed to determine the SARS-CoV-2 prevalence in animals from Swiss COVID-19 households and to assess the potential risk factors for infection. The study included 226 companion animals (172 cats, 76.1%; 49 dogs, 21.7%; and 5 other animals, 2.2%) from 122 COVID-19 households with 336 human household members (including 230 SARS-CoV-2-positive people). The animals were tested for viral RNA using an RT-qPCR and/or serologically for antibodies and neutralizing activity. Additionally, surface samples from animal fur and beds underwent an RT-qPCR. A questionnaire about hygiene, animal hygiene, and contact intensity was completed by the household members. A total of 49 of the 226 animals (21.7%) from 31 of the 122 households (25.4%) tested positive/questionably positive for SARS-CoV-2, including 37 of the 172 cats (21.5%) and 12 of the 49 dogs (24.5%). The surface samples tested positive significantly more often in households with SARS-CoV-2-positive animals than in households with SARS-CoV-2-negative animals (p = 0.011). Significantly more animals tested positive in the multivariable analysis for households with minors. For cats, a shorter length of outdoor access and a higher frequency of removing droppings from litterboxes were factors that were significantly associated with higher infection rates. The study emphasizes that the behavior of owners and the living conditions of animals can influence the likelihood of a SARS-CoV-2 infection in companion animals. Therefore, it is crucial to monitor the infection transmission and dynamics in animals, as well as to identify the possible risk factors for animals in infected households.