SARS-CoV-2 Infection and Clinical Signs in Cats and Dogs from Confirmed Positive Households in Germany.

On a global scale, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) poses a serious threat to the health of the human population. Not only humans can be infected, but also their companion animals. The antibody status of 115 cats and 170 dogs, originating from 177 German households known to have been SARS-CoV-2 positive, was determined by enzyme-linked immunosorbent assay (ELISA), and the results were combined with information gathered from a questionnaire that was completed by the owner(s) of the animals. The true seroprevalences of SARS-CoV-2 among cats and dogs were 42.5% (95% CI 33.5-51.9) and 56.8% (95% CI 49.1-64.4), respectively. In a multivariable logistic regression accounting for data clustered in households, for cats, the number of infected humans in the household and an above-average contact intensity turned out to be significant risk factors; contact with humans outside the household was a protective factor. For dogs, on the contrary, contact outside the household was a risk factor, and reduced contact, once the human infection was known, was a significant protective factor. No significant association was found between reported clinical signs in animals and their antibody status, and no spatial clustering of positive test results was identified.

2022 AAFP/EveryCat Feline Infectious Peritonitis Diagnosis Guidelines.

CLINICAL IMPORTANCE: Feline infectious peritonitis (FIP) is one of the most important infectious diseases and causes of death in cats; young cats less than 2 years of age are especially vulnerable. FIP is caused by a feline coronavirus (FCoV). It has been estimated that around 0.3% to 1.4% of feline deaths at veterinary institutions are caused by FIP. SCOPE: This document has been developed by a Task Force of experts in feline clinical medicine as the 2022 AAFP/EveryCat Feline Infectious Peritonitis Diagnosis Guidelines to provide veterinarians with essential information to aid their ability to recognize cats presenting with FIP. TESTING AND INTERPRETATION: Nearly every small animal veterinary practitioner will see cases. FIP can be challenging to diagnose owing to the lack of pathognomonic clinical signs or laboratory changes, especially when no effusion is present. A good understanding of each diagnostic test's sensitivity, specificity, predictive value, likelihood ratio and diagnostic accuracy is important when building a case for FIP. Before proceeding with any diagnostic test or commercial laboratory profile, the clinician should be able to answer the questions of 'why this test?' and 'what do the results mean?' Ultimately, the approach to diagnosing FIP must be tailored to the specific presentation of the individual cat. RELEVANCE: Given that the disease is fatal when untreated, the ability to obtain a correct diagnosis is critical. The clinician must consider the individual patient's history, signalment and comprehensive physical examination findings when selecting diagnostic tests and sample types in order to build the index of suspicion 'brick by brick'. Research has demonstrated efficacy of new antivirals in FIP treatment, but these products are not legally available in many countries at this time. The Task Force encourages veterinarians to review the literature and stay informed on clinical trials and new drug approvals.

Guest edited collection serological study of SARS-CoV-2 antibodies in japanese cats using protein-A/G-based ELISA.

BACKGROUND: Little is known about the epidemic status of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in cats in Japan due to insufficiently reliable seroepidemiological analysis methods that are easy to use in cats. RESULTS: We developed a protein-A/G-based enzyme-linked immunosorbent assay (ELISA) to detect antibodies against SARS-CoV-2 in cats. The assay was standardized using positive rabbit antibodies against SARS-CoV-2. The ELISA results were consistent with those of a conventional anti-feline-immunoglobulin-G (IgG)-based ELISA. To test the protein-A/G-based ELISA, we collected blood samples from 1,969 cats that had been taken to veterinary clinics in Japan from June to July 2020 and determined the presence of anti-SARS-CoV-2 antibodies. Nine cats were found to have SARS-CoV-2 S1-specific IgG, of which 4 had recombinant receptor-binding domain-specific IgG. Of those 9 samples, one showed neutralizing activity. Based on these findings, we estimated that the prevalence of SARS-CoV-2 neutralizing antibodies in cats in Japan was 0.05% (1/1,969 samples). This prevalence was consistent with the prevalence of neutralizing antibodies against SARS-CoV-2 in humans in Japan according to research conducted at that time. CONCLUSIONS: Protein-A/G-based ELISA has the potential to be a standardized method for measuring anti-SARS-CoV-2 antibodies in cats. The infection status of SARS-CoV-2 in cats in Japan might be linked to that in humans.

An investigation into an outbreak of pancytopenia in cats in the United Kingdom.

BACKGROUND: In spring 2021 increasing numbers of cats presenting with severe pancytopenia were noted in United Kingdom (UK). OBJECTIVE: To describe process and outcome of the investigation performed into the outbreak of pancytopenia in cats. ANIMALS: Five hundred and eighty client owned cats that presented with severe bi- or pancytopenia of unknown cause. METHODS: Real-time data collection was performed by an online registration forum available to all veterinary surgeons in UK. Data collected included demographics, clinicopathological findings, diagnostic testing, dietary and drug history, outcome and COVID household status. Mycotoxicological feed analysis was performed on feed samples of 3 diets frequently mentioned in the database and 3 control diets. RESULTS: Five hundred and eighty cats presented to 378 veterinary practices were included for analysis. Case fatality rate was 63.3%. Dietary history was available for 544 (93.8%) cats, of which 500 (86%) were fed 1 of 3 diets (which were recalled midinvestigation). 54 (9.3%) cats were not fed a recalled product, with diet information unknown in 26 (4.5%) cats. Analysis of feed samples revealed concentrations of hematotoxic trichothecene T-2/HT-2 mycotoxins greater than recommended by the European Commission in 5/7 recalled diet samples but in none of control diet samples. The trichothecene mycotoxin diacetoxyscirpenol (DAS) was detectable in all recalled diet samples but not in any of control samples. CONCLUSION AND CLINICAL IMPORTANCE: Contaminated-feed induced trichothecene mycotoxicosis should be considered as a differential diagnosis for pancytopenia in cats.

Molecular screening of SARS-CoV-2 in dogs and cats from households with infected owners diagnosed with COVID-19 during Delta and Omicron variant waves in Iran.

OBJECTIVE: The emergence of SARS-CoV-2 infection in dogs and cats in different countries worldwide raises concerns that pets are at a higher risk for spreading or transmitting of SARS-CoV-2 to humans and other pets and increased the research works about the zoonotic aspects and natural routes of infection in companion animals. The current study aimed to detect the SARS-CoV-2 in household dogs and cats living with COVID-19 positive owners. METHODS: Deep oropharyngeal and rectal swabs were collected from 30 household pets (20 cats and 10 dogs) living with COVID-19 positive owners from April 2021 to 2022 in Kerman, Iran. All dogs' and cats' samples were tested by real-time reverse transcription polymerase chain reaction for detection of SARS-CoV-2. RESULTS: Two household cats out of 20 examined (10%) were positive for SARS-CoV-2, whereas none of the examined dogs were positive for SARS-CoV-2. The two cats positive for SARS-CoV-2 were symptomatic and suffered from severe anorexia with maximum contact with their infected owners. CONCLUSION: This study reported the presence of SARS-CoV-2 in household cats in close contact with COVID-19 positive owners during the circulation of new SARS-CoV-2 variants (Delta and Omicron) in Iran and suggested that the transmission may have occurred from owners to their cats. Therefore, infected owners should eagerly limit close contact with their pets during COVID-19 illness.

SARS-CoV-2 delta variant infection in domestic dogs and cats, Thailand.

In June-September 2021, we investigated severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infections in domestic dogs and cats (n = 225) in Bangkok and the vicinities, Thailand. SARS-CoV-2 was detected in a dog and a cat from COVID-19 positive households. Whole genome sequence analysis identified SARS-CoV-2 delta variant of concern (B.1.617.2). Phylogenetic analysis showed that SARS-CoV-2 isolated from dog and cat were grouped into sublineage AY.30 and AY.85, respectively. Antibodies against SARS-CoV-2 could be detected in both dog (day 9) and cat (day 14) after viral RNA detection. This study raises awareness on spill-over of variant of concern in domestic animals due to human-animal interface. Thus, surveillance of SARS-CoV-2 in domestic pets should be routinely conducted.

SARS-CoV-2 transmission from infected owner to household dogs and cats is associated with food sharing.

OBJECTIVES: Several cases of reverse transmission of SARS-CoV-2 from human to pets were reported during the first year of the COVID-19 pandemic. Accordingly, the World Organization for Animal Health has recommended to improve SARS-CoV-2 surveillance on household animals to assess the risk of transmission between species. After such recommendation, we studied the potential SARS-CoV-2 infection in household dogs and cats in the city of Guayaquil, the most populated city in Ecuador. METHODS: Oral and nasal swab samples were collected from dogs and cats within 10 days of a positive SARS-CoV-2 test result of their owners. Total ribonucleic acid was extracted and detection of viral gene targets N and ORF1ab was performed by quantitative reverse transcription polymerase chain reaction. RESULTS: From the 50 cats and dogs tested, 12 were SARS-CoV-2 positive, giving a total positivity rate of 24%. A total of 1 of 8 cats tested positive, whereas 11 of 42 dogs were positive, yielding a positivity rate of 12.5% and 26.2%, respectively. SARS-CoV-2 was confirmed by whole genome sequencing. In addition, we also found a statistically significant association between SARS-CoV-2 pet positivity and food sharing with infected owners. CONCLUSION: This study is the second active surveillance of SARS-CoV-2 in household dogs and cats in Latin America. Moreover, it is the first study to address the risk factors associated with potential anthropogenic SARS-CoV-2 transmission to domestic cats and dogs. Given the high presence of free-roaming dogs and cats in rural and urban areas in Latin American countries and the high capacity shown by coronaviruses for interspecies transmission, our findings support the view that SARS-CoV-2 surveillance in pets is necessary to better understand the role that pet-human interaction plays in the COVID-19 spread.

Transmission of SARS-CoV-2 from humans to a 16-year-old domestic cat with comorbidities in Pennsylvania, USA.

BACKGROUND AND OBJECTIVES: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), besides causing human infection, has been shown to naturally infect several susceptible animal species including large cats (tigers, lions, pumas, spotted leopards), dogs, cats, ferrets, gorillas and minks. Cats and minks are continuing to be the most reported species with SARS-CoV-2 infections among animals but it needs to be investigated further. METHODS AND RESULTS: We report the detection of SARS-CoV-2 from a domestic cat that exhibited respiratory disease after being exposed to SARS-CoV-2 virus from humans in the same household. SARS-CoV-2 RNA was detected in two oropharyngeal swabs collected at two time points, 11 days apart; the first, when the cat was reported to be sick and the second, before euthanasia due to poor prognosis. The viral nucleic acid detected at two time points showed no genomic variation and resembled the clade GH circulating in humans in the United States. Clinical and pathological findings noted in this 16-year-old cat were consistent with respiratory and cardiac insufficiency. CONCLUSIONS: SARS-CoV-2 viral infection was likely an incidental clinical finding, as the virus was not detected in fixed lungs, heart, or kidney tissues. Only fresh lung tissue collected at necropsy showed the presence of viral nucleic acid, albeit at a very low level. Further research is needed to clarify the clinical course of SARS-CoV-2 in companion animals of advanced age and underlying cardiac disease.

Determining the role of natural SARS-CoV-2 infection in the death of domestic pets: 10 cases (2020-2021).

OBJECTIVE: To establish a pathoepidemiological model to evaluate the role of SARS-CoV-2 infection in the first 10 companion animals that died while infected with SARS-CoV-2 in the US. ANIMALS: 10 cats and dogs that tested positive for SARS-CoV-2 and died or were euthanized in the US between March 2020 and January 2021. PROCEDURES: A standardized algorithm was developed to direct case investigations, determine the necessity of certain diagnostic procedures, and evaluate the role, if any, that SARS-CoV-2 infection played in the animals' course of disease and death. Using clinical and diagnostic information collected by state animal health officials, state public health veterinarians, and other state and local partners, this algorithm was applied to each animal case. RESULTS: SARS-CoV-2 was an incidental finding in 8 animals, was suspected to have contributed to the severity of clinical signs leading to euthanasia in 1 dog, and was the primary reason for death for 1 cat. CONCLUSIONS AND CLINICAL RELEVANCE: This report provides the global community with a standardized process for directing case investigations, determining the necessity of certain diagnostic procedures, and determining the clinical significance of SARS-CoV-2 infections in animals with fatal outcomes and provides evidence that SARS-CoV-2 can, in rare circumstances, cause or contribute to death in pets.

Detection of SARS-CoV-2 variant B.1.1.7 in a cat in Germany.

Several non-variant of concern SARS-CoV-2 infections in pets have been reported as documented in the OIE and GISAID databases and there is only one fully documented case of an alpha variant of concern (VOC)(B.1.1.7) in the United States so far. Here, we describe the first case in a cat infected with the alpha SARS-CoV-2 variant in Germany. A cat suffering from pneumonia was presented to a veterinary practice. The pneumonia was treated symptomatically, but 16 days later the cat was presented again. Since the owner had been tested positive for a SARS-CoV-2 infection in the meantime, swab samples were taken from the cat and analyzed for SARS-CoV-2 specific nucleic acids. The various RT-qPCR analyses and whole-genome sequencing revealed the presence of the SARS-CoV-2 B.1.1.7 variant in this cat. This study shows that pets living in close contact with SARS-CoV-2 B.1.1.7 infected owners can contract this virus and also suffer from a respiratory disease. It is not clear yet whether onward transmissions to other cats and humans can occur. To minimize transmission risks, pet owners and veterinarians should comply to the hygienic rules published by OIE and others. It must be stated, that infections of cats with SARS-CoV-2 is still a rare event. Cats with clinical signs of a respiratory disease should be presented to a veterinarian, who will decide on further steps.

First Reported Cases of SARS-CoV-2 Infection in Companion Animals - New York, March-April 2020.

On April 22, CDC and the U.S. Department of Agriculture (USDA) reported cases of two domestic cats with confirmed infection with SARS-CoV-2, the virus that causes coronavirus disease 2019 (COVID-19). These are the first reported companion animals (including pets and service animals) with SARS-CoV-2 infection in the United States, and among the first findings of SARS-CoV-2 symptomatic companion animals reported worldwide. These feline cases originated from separate households and were epidemiologically linked to suspected or confirmed human COVID-19 cases in their respective households. Notification of presumptive positive animal test results triggered a One Health* investigation by state and federal partners, who determined that no further transmission events to other animals or persons had occurred. Both cats fully recovered. Although there is currently no evidence that animals play a substantial role in spreading COVID-19, CDC advises persons with suspected or confirmed COVID-19 to restrict contact with animals during their illness and to monitor any animals with confirmed SARS-CoV-2 infection and separate them from other persons and animals at home (1).

SARS-CoV-2 Infection in Dogs and Cats from Southern Germany and Northern Italy during the First Wave of the COVID-19 Pandemic.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has affected millions of people globally since its first detection in late 2019. Besides humans, cats and, to some extent, dogs were shown to be susceptible to SARS-CoV-2, highlighting the need for surveillance in a One Health context. Seven veterinary clinics from regions with high incidences of coronavirus disease (COVID-19) were recruited during the early pandemic (March to July 2020) for the screening of patients. A total of 2257 oropharyngeal and nasal swab specimen from 877 dogs and 260 cats (including 18 animals from COVID-19-affected households and 92 animals with signs of respiratory disease) were analyzed for the presence of SARS-CoV-2 RNA using reverse transcriptase real-time polymerase chain reaction (RT-qPCR) targeting the viral envelope (E) and RNA dependent RNA polymerase (RdRp) genes. One oropharyngeal swab from an Italian cat, living in a COVID-19-affected household in Piedmont, tested positive in RT-qPCR (1/260; 0.38%, 95% CI: 0.01-2.1%), and SARS-CoV-2 infection of the animal was serologically confirmed six months later. One oropharyngeal swab from a dog was potentially positive (1/877; 0.1%, 95% CI: 0.002-0.63%), but the result was not confirmed in a reference laboratory. Analyses of convenience sera from 118 animals identified one dog (1/94; 1.1%; 95% CI: 0.02-5.7%) from Lombardy, but no cats (0/24), as positive for anti-SARS-CoV-2 receptor binding domain (RBD) antibodies and neutralizing activity. These findings support the hypothesis that the prevalence of SARS-CoV-2 infection in pet cat and dog populations, and hence, the risk of zoonotic transmission to veterinary staff, was low during the first wave of the pandemic, even in hotspot areas.

First detection and molecular analysis of SARS-CoV-2 from a naturally infected cat from Argentina.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the etiological agent of coronavirus disease 2019 (COVID-19), has rapidly spread worldwide. Studies of transmission of the virus carried out in animals have suggested that certain animals may be susceptible to infection with SARS-CoV-2. The aim of the present study was to investigate the infection of SARS-CoV-2 in pets (18 cats and 20 dogs) from owners previously confirmed as COVID-19-positive. Oropharyngeal and rectal swabs were taken and analyzed by real-time RT-PCR assays, while blood samples were taken for antibody detection. Of the total pets analyzed, one cat was found reactive to SARS-CoV-2 by real-time RT-PCR of an oropharyngeal and a rectal swab. This cat presented only sneezing as a clinical sign. Serological analysis confirmed the presence of antibodies in the serum sample from this cat, as well as in the serum from another cat non-reactive to real-time RT-PCR. Complete sequence and phylogenetic analysis allowed determining that the SARS-CoV-2 genome belonged to the B.1.499 lineage. This lineage has been reported in different provinces of Argentina, mainly in the Metropolitan Area of Buenos Aires. This study notifies the first detection of the natural infection and molecular analysis of SARS-CoV-2 in a cat from Argentina whose owner where COVID-19-positive. Although there is currently no evidence that cats can spread COVID-19, results suggest that health authorities should test pets with COVID-19-positive owners.

The Second Wave of SARS-CoV-2 Circulation-Antibody Detection in the Domestic Cat Population in Germany.

Registered cases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections in the German human population increased rapidly during the second wave of the SARS-CoV-2 pandemic in winter 2020/21. Since domestic cats are susceptible to SARS-CoV-2, the occurrence of trans-species transmission needs to be monitored. A previous serosurvey during the first wave of the pandemic detected antibodies against SARS-CoV-2 in 0.65% of feline serum samples that were randomly sampled across Germany. In the here-presented follow-up study that was conducted from September 2020 to February 2021, the seroprevalence rose to 1.36% (16/1173). This doubling of the seroprevalence in cats is in line with the rise of reported cases in the human population and indicates a continuous occurrence of trans-species transmission from infected owners to their cats.

SARS-CoV-2 B.1.1.7 variant of concern detected in a pet dog and cat after exposure to a person with COVID-19, USA.

As part of a longitudinal household transmission study of pets living with persons with COVID-19 in Texas, two pets were confirmed to be infected with the SARS-CoV-2 B.1.1.7 variant of concern (VOC). The pets were a dog and a cat from the same household, sampled two days after their owner tested positive for COVID-19. The oral, nasal and fur swabs for both pets tested positive for SARS-CoV-2 by qRT-PCR and consensus whole-genome sequences from the dog and cat were 100% identical and matched the B.1.1.7 VOC. Virus was isolated from the cat's nasal swab. One month after initial detection of infection, the pets were re-tested twice at which time only the fur swabs (both pets) and oral swab (dog only) remained positive, and neutralizing antibodies for SARS-CoV-2 were present in both animals. Sneezing by both pets was noted by the owner in the weeks between initial and follow-up testing. This study documents the first detection of B.1.1.7. in companion animals in the United States, and the first genome recovery and isolation of B.1.1.7 variant of concern globally in any animal.

Limited cross-species transmission and absence of mutations associated with SARS-CoV-2 adaptation in cats: A case study of infection in a small household setting.

In the present study, the course of SARS-CoV-2 natural infection in two asymptomatic cats, which were negative for immunosuppressive retroviral infections, is investigated. The source of the virus for the cats was their COVID-19-affected owner, with whom they were in continuous proximity in a small household setting. The owner's signs included fatigue, sneezing, anosmia and loss of taste, and diagnosis was confirmed 4 days after symptom onset. Oropharyngeal and faecal swabs were collected from the cats, to investigate the course of SARS-CoV-2 RNA concentrations, as well as the directionality of the chain of virus transmission. Both infected cats were real-time RT-PCR-positive on various time-points. Pharyngeal shedding of at least 6 days was observed in them, with high SARS-CoV-2 titres (> 7 Log10 copies/swab) on the first sampling time-point, that is, 7 days after the onset of owner's clinical signs. In one cat, after the initial decline, slightly increasing virus titres were measured 3 to 6 days after the first real-time RT-PCR-positive swab. Serological testing of this cat revealed absence of seroconversion. The course of viral RNA concentrations in the faecal swabs of the other cat was similar to that in its pharynx. The detected SARS-CoV-2 strains, from both infected cats and their owner, underwent whole-genome sequencing, revealing the absence of emergence of cross-species adaptive mutations in cats. The results support the notion that human SARS-CoV-2 strains are relatively well-adapted to cats. It is still unclear whether asymptomatic animals could play a role in COVID-19 epidemiology, in case of interaction with naïve animals and/or people. Our findings highlight difficulties in SARS-CoV-2 transmission to cats, as neither the two infected cats nor their owner was able to transmit the virus to a third cat living in the same small flat, despite their very close contact during the days corresponding to high virus shedding.

Detection and Genome Sequencing of SARS-CoV-2 in a Domestic Cat with Respiratory Signs in Switzerland.

Since the emergence of coronavirus disease (COVID-19) in late 2019, domestic cats have been demonstrated to be susceptible to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) under natural and experimental conditions. As pet cats often live in very close contact with their owners, it is essential to investigate SARS-CoV-2 infections in cats in a One-Health context. This study reports the first SARS-CoV-2 infection in a cat in a COVID-19-affected household in Switzerland. The cat (Cat 1) demonstrated signs of an upper respiratory tract infection, including sneezing, inappetence, and apathy, while the cohabiting cat (Cat 2) remained asymptomatic. Nasal, oral, fecal, fur, and environmental swab samples were collected twice from both cats and analyzed by RT-qPCR for the presence of SARS-CoV-2 viral RNA. Both nasal swabs from Cat 1 tested positive. In addition, the first oral swab from Cat 2 and fur and bedding swabs from both cats were RT-qPCR positive. The fecal swabs tested negative. The infection of Cat 1 was confirmed by positive SARS-CoV-2 S1 receptor binding domain (RBD) antibody testing and neutralizing activity in a surrogate assay. The viral genome sequence from Cat 1, obtained by next generation sequencing, showed the closest relation to a human sequence from the B.1.1.39 lineage, with one single nucleotide polymorphism (SNP) difference. This study demonstrates not only SARS-CoV-2 infection of a cat from a COVID-19-affected household but also contamination of the cats' fur and bed with viral RNA. Our results are important to create awareness that SARS-CoV-2 infected people should observe hygienic measures to avoid infection and contamination of animal cohabitants.

Frequency of respiratory pathogens and SARS-CoV-2 in canine and feline samples submitted for respiratory testing in early 2020.

OBJECTIVES: The emergence of the 2019 novel coronavirus (SARS-CoV-2) has necessitated evaluation of the potential for SARS-CoV-2 infection in dogs and cats. Using a large data set, we evaluated the frequency of SARS-CoV-2 and other respiratory pathogens in samples submitted for respiratory testing from mid-February to mid-April 2020. MATERIALS AND METHODS: A SARS-CoV-2 real-time PCR was developed and validated. A subset of canine and feline samples submitted for respiratory pathogen panel testing to reference laboratories in Asia, Europe, and North America were also tested for SARS-CoV-2. The frequency of respiratory pathogens was compared for the February-April period of 2020 and 2019. RESULTS: Samples from 4616 patients were included in the study and 44% of canine and 69% of feline samples were PCR positive with Mycoplasma cynos and Bordetella bronchiseptica and Mycoplasma felis and feline calicivirus, respectively. No SARS-CoV-2 infections were identified. Positive results for respiratory samples were similar between years. CLINICAL SIGNIFICANCE: The data in this study suggest that during the emergence of the SARS-CoV-2 pandemic in early 2020, respiratory diseases in tested pet cats and dogs were caused by common veterinary pathogens and that SARS-CoV-2 infections in dogs and cats are rare.