Feline Panleukopenia: A Re-emergent Disease

Chemical Sensors and Biosensors for Point-of-Care Testing of Pets: Opportunities for Individualized Diagnostics of Companion Animals

Point-of-care testing (POCT) is recognized as one of the most disruptive medical technologies for rapid and decentralized diagnostics. Successful commercial examples include portable glucose meters, pregnancy tests, and COVID-19 self-tests. However, compared to advancements in human healthcare, POCT technologies for companion animals (pets) remain significantly underdeveloped. This Review explores the latest advancements in pet POCT and examines the challenges and opportunities in the field for individualized diagnostics of cats and dogs. The most frequent diseases and their respective biomarkers in blood, urine, and saliva are discussed. We examine key strategies for developing the next-generation POCT devices by harnessing the potential of selective (bio)receptors and high-performing transducers such as lateral flow tests and electrochemical (bio)sensors. We also present the most recent research initiatives and the successful commercial pet POCT technologies. We discuss future trends in the field, such the role of biomarker discovery and development of wearable, implantable, and breath sensors. We believe that advancing pet POCT technologies benefits not only animals but also humans and the environment, supporting the One Health approach.

Retrospective analysis of clustered neuroinflammatory and neurodegenerative diseases in captive lions in the early 1970s

Rustrela virus (RusV), a recently discovered pathogen for domestic and wildlife animals, was identified as the causative agent of meningoencephalomyelitis in domestic cats and various zoo animals including lions. To analyze a past outbreak of increased mortality in lions and to reveal its possible etiological relationship with an RusV infection, this retrospective study re-evaluates 20 cases of lions originating from a zoo in Western Germany using archived formalin-fixed paraffin-embedded (FFPE) tissues. Animals with different neurologic signs were submitted for necropsy between December 1970 and April 1971. Eight lions (40%) suffered from non-suppurative meningoencephalomyelitis with RusV RNA and antigen detectable in the central nervous system (CNS). Twelve animals (60%) were negative for RusV. Eleven animals had an etiologically undetermined degenerative encephalomyelopathy characterized by dilated myelin sheaths, myelinophages, and spheroids. Eight of these 12 lions suffered from an erosive, lymphohistiocytic enteritis with nuclear inclusion bodies in enterocytes associated with parvoviral antigen and nucleic acid in the intestines, lymph nodes, and spleen, but not in the CNS. Five of the parvovirus-infected animals had a granulomatous inflammation in mesenteric lymph nodes that was also the only detectable lesion in one other lion. Acid-fast bacilli and Mycobacterium bovis DNA confirmed the diagnosis of tuberculosis. In summary, this study provides convincing evidence of the usefulness of long-term stored FFPE material for further investigations using immunohistochemistry, reverse transcription quantitative polymerase chain reaction, and in situ hybridization for resolving past disease outbreaks. It provides further insights into the epidemiology of infectious agents like RusV and parvovirus.

First Description of a Carnivore Protoparvovirus Associated with a Clinical Case in the Iberian Lynx (Lynx pardinus)

One of the main threats for the survival of the Iberian lynx is infectious disease. Feline parvoviruses cause often fatal diseases in cats and have been isolated from different species of Felidae and other carnivores. The present study is the first description of a parvoviral sequence isolated from the brain of an Iberian lynx which died four weeks after being transferred to a quarantine centre from a hunting estate in Castilla-La-Mancha (southern border of the Iberian plateau). Four days prior to death, it had developed anorexia and muscle weakness. The nucleotide sequence, at 4589 nt long (GenBank PP781551), was most proximal to that isolated from a Eurasian badger in Italy but also showed great homology with others from cats and other carnivores isolated in Spain and Italy, including that from a cat sequenced by us to elucidate the origin of the infection, which has not been clarified. The phylogenetic analysis of the capsid protein, VP2, which determines tropism and host range, confirmed that the lynx sequence was most proximal to feline than to canine parvoviruses, and was thus typed as Protoparvovirus carnivoran1. More studies, including serology, are needed to understand the pathogenesis of this infection.

Enteritis in raccoons (Procyon lotor) caused by an infection with zoonotic Salmonella and carnivore parvovirus

BACKGROUND

The raccoon (Procyon lotor) is a potential carrier of a large number of zoonotic pathogens, and its population is increasing in urban areas in Europe. In the present study, we investigated two cases of fatal enteritis in raccoons in Germany. Parvoviruses are a common cause of enteritis in raccoons, however in these cases an additional infection with zoonotic Salmonella was found, which has not yet been described in other countries than the United States.

CASE PRESENTATION

Two female raccoons, aged 14 and 18 weeks, were submitted for necropsy. Histopathology of the small intestine revealed crypt degeneration and necrosis, atrophy and fusion of villi, as well as numerous bacteria partially covered by fibrinous pseudomembranes. By microbiological culture of small intestinal samples Salmonella enterica subsp. enterica Serovar Kottbus and Salmonella enterica subsp. enterica Serovar Ferruch were isolated, respectively. In addition, carnivore protoparvovirus type 1 was identified in the small intestine of both animals.

CONCLUSIONS

The infection of raccoons with carnivore protoparvovirus type 1 results in immunosuppression, which facilitates the spread of other pathogens. Both isolated Salmonella serovars represent a significant zoonotic threat for humans being in contact with the raccoon. Furthermore, in raccoons with sudden death a double infection with carnivore protoparvovirus type 1 and Salmonella should be considered as an important differential diagnosis.

Epidemiological and Molecular Investigation of Feline Panleukopenia Virus Infection in China

The feline panleukopenia virus (FPV) is a highly contagious virus that affects cats worldwide, characterized by leukopenia, high temperature and diarrhea. Recently, the continuous prevalence and variation of FPV have attracted widespread concern. The aim of this study was to investigate the isolation, genetic evolution, molecular characterization and epidemiological analysis of FPV strains among cats and dogs in China from 2019 to 2024. The 41 FPV strains, including 38 feline strains and 3 canine strains, were isolated from rectal swab samples by inoculating monolayer FK81 cells and performing a plaque purification assay. The viral and hemagglutination titers of these 41 FPV strains were 104.33~106.33 TCID50/0.1 mL and 7.0 log2~9.7 log2, respectively. Based on the complete VP2 gene, the nucleotide homology of these FPV strains was 98.91~100%, and the homology with 24 reference FPV strains from different countries and hosts was 98.85~100%. The phylogenetic analysis revealed that 41 FPV strains were more closely related to the FPV strains of Asian origin (Asian FPV strain group) than those of European and American origin (European and American FPV strain group). Furthermore, 12 mutation sites of the VP2 protein were found in these FPV strains, of which 91 and 232 amino acid sites were previously reported. Moreover, the 91 amino acid site was found to be a positive selection site with the highest dN/dS value in the selection pressure analysis. Importantly, 35 FPV strains with 91S substitution in the VP2 protein (FPV-VP2-91S strains) had formed obvious evolutionary branches in the Asian FPV strain group. The analysis of all available VP2 protein sequences of Chinese FPV strains in the GenBank database showed that the occurrence rate of FPV-VP2-91S strains had been increasing from 15.63% to 100% during 2017~2024, indicating that the FPV-VP2-91S substitution in the VP2 protein was a noteworthy molecular characteristic of the dominant FPV strains in China. These results contribute to a better understanding of their genetic evolution and renew the knowledge of FPV molecular epidemiology.

Filgrastim Efficiency in Cats Naturally Infected with Feline Panleukopenia Virus

Feline Panleukopenia (FPL) infection is caused by feline panleukopenia virus (FPV), and it is considered one of the most severe cat's infectious diseases. Since there is no specific antiviral treatment for FPL, the therapeutic protocol usually is focused on fluid therapy and supportive care. However, filgrastim, a granulocyte colony-stimulating factor (G-CSF) used in human medicine to treat neutropenia and leukopenia, has been lately used in treating FPV disease, providing promising results. During January 2022 and September 2024, twenty-two cats diagnosed with feline panleukopenia virus were subjected to filgrastim (Zarzio®, Sandoz, Kundl, Austria) administration at a dose of 6 µg/kg for 3 consecutive days. The 4th day was a break day, and in the 5th day, the complete blood count was repeated. White blood cells, lymphocytes, monocytes, neutrophils and eosinophils parameters improved after Zarzio® administration, with a significant statistical difference (p < 0.01) when their values between day 1 (pre Zarzio® administration) and day 5 (post Zarzio® administration) were analysed. However, red blood cells, haemoglobin, haematocrit and platelets parameters registered a considerable reduction from day 1 to day 5 with a significant statistical difference (p < 0.01), considered as post-administration side effects. In our study, the survival rate following Zarzio® administration was 100%, suggesting that the protocol involving three doses is effective in restoring the leukopenia and neutropenia.

Molecular typing of Protoparvovirus carnivoran 1 in Egyptian cats diagnosed with feline panleukopenia

Feline panleukopenia (FPL) in cats is caused by either feline parvovirus (FPV) or canine parvovirus (CPV-2), which belong to the same species "Protoparvovirus carnivoran 1". While FPV is widely recognized as the principal cause of FPL, CPV-2 has been detected at a higher rate than FPV in sick cats in a recent Egyptian study. To assess this conflict, the present study aimed to determine which Protoparvovirus carnivoran 1 is commonly associated with FPL in Egyptian cats. From Dec-2022 to Jan-2024, 43 cats presenting with acute gastroenteritis and testing positive for FPL using in-clinic assay, SNAP® parvo, were tested for Protoparvovirus carnivoran 1 DNA using conventional PCR. Typing of Protoparvovirus carnivoran 1 was conducted by partial VP2 gene sequencing. Additional epidemiological aspects of the disease were investigated, including seasonal pattern, case-fatality rate, median survival time to death, and the association between FPL outcomes and selected factors like age, sex, vaccination status, and clinical signs (vomiting and diarrhea). All cats tested positive for Protoparvovirus carnivoran 1 DNA and FPV was detected in all cats with strong PCR amplicons (n=39). The following seasonal pattern was recorded: cases emerging in autumn, peaking during winter, declining in spring, and disappearing in summer. The case-fatality rate was 41.6 %, and the median time to death was two days. None of the studied factors affected FPL outcomes. In conclusion, FPL in Egyptian cat populations is primarily caused by FPV, not CPV-2, and is particularly prevalent in winter.

Two novel sites determine genetic relationships between CPV-2 and FPV: an epidemiological survey of canine and feline parvoviruses in Changchun, China (2020)

Canine parvovirus (CPV-2) and feline parvovirus (FPV) cause severe hemorrhagic diarrhea disease in dogs, cats, and fur-bearing and wildlife carnivores worldwide, continuing to pose significant threats. In this study, 140 rectal swabs were collected from 70 domestic dogs and 70 cats with clinical diarrhea in veterinary clinics in Changchun during 2020. A total of 64.3% (45/70) of dogs and 55.7% (39/70) of cats tested positive for CPV-2 or FPV using colloidal gold strips. Amino acid (aa) sequence alignment of the VP2 protein from 39 CPV-2 and 36 FPV samples revealed that 79.5% (31/39) were CPV-2c, 17.9% (7/39) were a new CPV-2a, and 2.6% (1/39) were mink enteritis virus (MEV). and 8.3% (3/36) FPV from the cats was infected by CPV-2, which suggested that CPV-2c was the dominant variant in dogs and FPV was the major pathogen in cats in Changchun city. Phylogenetic relationships of VP2 genes showed that 26 parvoviruses were closely related to domestic strains previously published in China; however, 8 FPVs and CPV-JL-15/China/2020 were clustered in the lineage of South Asiatic and European countries, and 7 out of 8 FPVs were close to Italy. In addition to Q247H, I248Y, F544Y, and E/V545V/K, two novel site mutations of N23D or L630P in NS1 protein, associated with viral cross-species transmissions, were first found as a reminder of genetic relationships of CPV-2 variants and FPVs in the same branch. Thus, regular and massive virus surveillance of parvovirus is necessary to cope with its ongoing infection, circulation, mutations, and evolutions to new subtypes with strong survival abilities.

Evolutionary Dynamics and Pathogenicity Analysis of Feline Panleukopenia Virus in Xinjiang, China

Feline panleukopenia virus (FPV), a globally pervasive and highly pathogenic pathogen, has garnered significant attention recently due to the cross-species transmission of its variants. Despite the vast body of research conducted on FPV, studies exploring its evolutionary history, dynamics, and the factors driving its evolution remain scarce. The pathogenicity of strains with the prevalent mutations (A91S and I101T) in the VP2 protein has also not been fully elucidated. This study conducted a comparative analysis of FPV VP2 sequences sourced from Xinjiang province in China, other provinces in China, and other countries. It was confirmed that the evolutionary rate of FPV approached that of RNA viruses, at approximately 1.13 × 10-4 substitutions/site/year. The study reconstructed molecular models of the VP2 protein with the A91S and I101T mutations and used viral strains carrying these mutations to perform the animal regression experiment. It was confirmed that isolates with the A91S and I101T mutations could cause typical leukopenia and acute enteritis symptoms, suggesting that the mutant strains still possess certain pathogenicity. This is the first study to report on the evolutionary dynamics of FPV in Xinjiang, China, and it emphasized the importance of continuously monitoring FPV evolutionary dynamics.

CASE-CONTROL STUDY OF THE FREQUENCY AND ETIOLOGY OF ATAXIA IN ASIATIC LIONS (PANTHERA LEO PERSICA) BETWEEN 2002 AND 2020

The Asiatic lion (Panthera leo persica) is an endangered species with a slowly increasing captive and wild population. Several zoos from within the European Association of Zoos and Aquaria Ex Situ Program reported Asiatic lions with neurological signs such as (progressive) ataxia, and stargazing. The aim of this study was to evaluate the frequency (prevalence and incidence) and etiology of these clinical signs within the captive Asiatic lion population. The medical history of 74 Asiatic lions (36 healthy and 38 affected) was retrieved and reviewed for blood tests (biochemical, hematological, and retinol), diagnostic imaging (MRI and CT scans) and postmortem examinations. The data of the affected lions was compared with those of healthy lions. Between 2002 and 2020, the prevalence of ataxia ranged from 0.6% in 2004 to 13.0% in 2020. The incidence of ataxia was variable per year between 2002 and 2020 and ranged between 0 and 40%. Besides ataxia, stiffness and lameness were the most described signs in this study. Blood results showed lower total protein, ALT and creatinine, and higher phosphate in lions with neurological signs. Moreover, neurologically affected lions showed a significant lower blood retinol than the control lions (0.59-0.81 µmol/L). The most important finding in diagnostic imaging and necropsy included caudal fossa hyperostosis and cerebellar herniation. These abnormalities are similar as found in African lions (Panthera leo) with calvarial hyperostosis syndrome associated with vitamin A deficiency. Leucomyelopathy, syringomyelia (in one case combined with cerebellar herniation) and incidental mineralization of the dura mater were also described. A possible congenital/hereditary component should not be excluded.

The coding complete genomic sequence of a feline panleukopenia virus detected from a domestic cat (Felis catus) in Chattogram, Bangladesh

The coding complete genome sequence of the feline panleukopenia virus (FPLV), detected from an indigenous cat in Bangladesh, has been determined. The genome spans 4,842 bp and contains four protein-coding genes. The genome will contribute to a comprehensive understanding of the genetic traits and evolutionary trends of FPLV.

Evaluation of feline mesenchymal stem cell susceptibility to feline viruses

Feline mesenchymal stem cells (fMSCs) are well known for their robust differentiation capabilities and are commonly used in studying immune-related diseases in cats. Despite their importance, the susceptibility of fMSCs to viral infections remains uncertain. This study aimed to assess the susceptibility of feline adipose-derived mesenchymal stem cells (fAD-MSCs) and feline umbilical cord-derived mesenchymal stem cells (fUC-MSCs) to common feline viruses, including feline coronavirus (FCoV), feline herpesvirus type 1 (FHV-1), and feline panleukopenia virus (FPV). The results demonstrated that both FCoV and FHV-1 were able to infect both types of cells, while FPV did not exhibit cytopathic effects on fUC-MSCs. Furthermore, all three viruses were successfully isolated from fAD-MSCs. These findings suggest that certain feline viruses can replicate in fMSCs, indicating potential limitations in using fMSCs for treating viral diseases caused by these specific viruses. This study has important clinical implications for veterinarians, particularly in the management of viral diseases.

Viral pathogens in domestic cats in southern Italy: A retrospective analysis in Sicily, 2020-2022

A retrospective study was carried out on selected feline viral pathogens detected in domestic cat in Sicily, southern Italy. Samples from 64 cats, collected from 2020 to 2022, were analysed for the presence of feline panleukopenia virus, canine parvovirus type 2 (CPV-2), feline coronavirus (FCoV), feline calicivirus (FCV), feline herpesvirus type 1, norovirus (NoV), and rotavirus (RoV). Single (45 %) or mixed (38 %) viral infections were detected. FPV, related with other Italian FPV strains, remains the main viral cause of infection (66 %). CPV-2c Asian lineage strains (3 %) were detected for the first time in domestic cats in Europe. FCoV (29.6 %), either enteric or systemic, and systemic FCV (18.7 %) infections were detected in positive cats. Less commonly reported viruses (GIV.2/GVI.2 NoVs, RoV), potentially related to the animal/human interface, were detected at lower rates as well (5 %). The present epidemiological data suggest the need to improve disease prevention, immunization, and biosecurity strategies.

Molecular Characterization of Feline Parvovirus from Domestic Cats in Henan Province, China from 2020 to 2022

Carnivore protoparvovirus-1, feline parvovirus (FPV), and canine parvovirus (CPV) continue to spread in companion animals all over the world. As a result, FPV and CPV underwent host-to-host transfer in carnivorous wild-animal hosts. Here, a total of 82 fecal samples of suspected cat FPV infections were collected from Henan Province from 2020 to 2022. The previously published full-length sequence primers of VP2 and NS1 genes were used to amplify the targeted genes of these samples, and the complete gene sequences of 11 VP2 and 21 NS1 samples were obtained and analyzed. Analysis showed that the amino acid homology of the VP2 and NS1 genes of these isolates was 96.1-100% and 97.6-100%, respectively. The phylogenetic results showed that the VP2 and NS1 genes of the local isolates were mainly concentrated in the G1 subgroup, while the vaccine strains were distributed in the G3 subgroup. Finally, F81 cells were inoculated with the local endemic isolate Luoyang-01 (FPV-LY strain for short) for virus amplification, purification, and titer determination, and the pathogenesis of FPV-LY was detected. After five generations of blind transmission in F81 cells, cells infected with FPV-LY displayed characteristic morphological changes, including a round, threadlike, and wrinkled appearance, indicative of viral infection. The virus titer associated with this cytopathic effect (CPE) was measured at 1.5 × 106 TCID50/mL. Subsequent animal regression tests confirmed that the virus titer of the PFV-LY isolate remained at 1.5 × 106 TCID50/mL, indicating its highly pathogenic nature. Cats exposed to the virus exhibited typical clinical symptoms and pathological changes, ultimately succumbing to the infection. These results suggest that the gene mutation rate of FPV is increasing, resulting in a complex pattern of gene evolution in terms of host preference, geographical selection, and novel genetic variants. The data also indicate that continuous molecular epidemiological surveillance is required to understand the genetic diversity of FPV isolates.

Therapeutic Effects of Propionibacterium acnes and Lipopolysaccharide from Escherichia coli in Cats with Feline Panleukopenia

The objective of this study was to investigate the therapeutic effects of inactivated Propionibacterium acnes and lipopolysaccharide derived from Escherichia coli cells in cats affected by feline panleukopenia virus (FPV). A retrospective study of 80 FPV-positive cats was divided into two groups: a treatment group receiving inactivated Propionibacterium acnes and lipopolysaccharide derived from Escherichia coli cells along with supportive treatment and a no-treatment group receiving only supportive treatment. There was no significant difference in the total white blood cell counts between the two groups. However, the total white blood cell counts of both groups were low on day 0 and increased significantly on days 3 and 6 of treatment. Additionally, the white blood cell counts in the treatment group significantly increased during days 3 to 6 compared with those of the no-treatment group (p < 0.01). The mortality rate was not significantly different between the two groups. In a prospective study, the serum and fecal immunoglobulin A (IgA) levels were measured in both groups. There were no significant differences in IgA levels between the two groups in either the serum or feces.

Investigation of canine parvovirus occurrence in cats with clinical signs of feline panleukopenia in Slovakia - pilot study

Introduction

Feline panleukopenia is a contagious viral disease caused by the feline panleukopenia virus (FPV). A closely related pathogen is canine parvovirus (CPV), and amino acid substitutions in this virus allow it to acquire a feline host range. In feline hosts, the disease induced by CPV manifests with similar symptoms to those caused by FPV or milder ones, leading to its underdiagnosis. The aim of this study was to determine the presence of CPV type 2 (CPV-2) in cats with clinical symptoms of panleukopenia and to assess the use of commercial CPV antigen tests for the clinical diagnosis of FPV.

Material and Methods

Samples from 59 cats from central Slovakia were included in the study. Rectal swabs were collected and clinically tested for parvovirus infection using a commercial antigen test. Antigen-positive samples were confirmed by PCR targeting the viral VP2 gene. The sequences of the PCR products were established with the Sanger method.

Results

Of 59 samples, 23 were revealed to be positive for parvovirus infection by both antigen and PCR test (38.9%). Analysis with the National Center for Biotechnology Information BLASTn application showed 99.78-100% pairwise identity with FPV. The mortality rate of parvovirus-infected cats included in this study was 8.69% (2/23).

Conclusion

Although feline disease with CPV-2 was not confirmed, the CPV antigen test was able to detect FPV infection.

Novel mutation N588 residue in the NS1 protein of feline parvovirus greatly augments viral replication

Feline parvovirus (FPV) infection is highly fatal in felines. NS1, which is a key nonstructural protein of FPV, can inhibit host innate immunity and promote viral replication, which is the main reason for the severe pathogenicity of FPV. However, the mechanism by which the NS1 protein disrupts host immunity and regulates viral replication is still unclear. Here, we identified an FPV M1 strain that is regulated by the NS1 protein and has more pronounced suppression of innate immunity, resulting in robust replication. We found that the neutralization titer of the FPV M1 strain was significantly lower than that of the other strains. Moreover, FPV M1 had powerful replication ability, and the FPV M1-NS1 protein had heightened efficacy in repressing interferon-stimulated genes (ISGs) expression. Subsequently, we constructed an FPV reverse genetic system, which confirmed that the N588 residue of FPV M1-NS1 protein is a key amino acid that bolsters viral proliferation. Recombinant virus containing N588 also had stronger ability to inhibit ISGs, and lower ISGs levels promoted viral replication and reduced the neutralization titer of the positive control serum. Finally, we confirmed that the difference in viral replication was abolished in type I IFN receptor knockout cell lines. In conclusion, our results demonstrate that the N588 residue of the NS1 protein is a critical amino acid that promotes viral proliferation by increasing the inhibition of ISGs expression. These insights provide a reference for studying the relationship between parvovirus-mediated inhibition of host innate immunity and viral replication while facilitating improved FPV vaccine production.IMPORTANCEFPV infection is a viral infectious disease with the highest mortality rate in felines. A universal feature of parvovirus is its ability to inhibit host innate immunity, and its ability to suppress innate immunity is mainly accomplished by the NS1 protein. In the present study, FPV was used as a viral model to explore the mechanism by which the NS1 protein inhibits innate immunity and regulates viral replication. Studies have shown that the FPV-NS1 protein containing the N588 residue strongly inhibits the expression of host ISGs, thereby increasing the viral proliferation titer. In addition, the presence of the N588 residue can increase the proliferation titer of the strain 5- to 10-fold without affecting its virulence and immunogenicity. In conclusion, our findings provide new insights and guidance for studying the mechanisms by which parvoviruses suppress innate immunity and for developing high-yielding FPV vaccines.

One-step triplex TaqMan quantitative reverse transcription polymerase chain reaction for the detection of feline coronavirus, feline panleukopenia virus, and feline leukemia virus

Background and Aim

Feline coronavirus (FCoV), feline panleukopenia virus (FPV), and feline leukemia virus (FeLV) are prevalent throughout China and significantly threaten cat health. These viruses cause similar manifestations and pathological damage. Rapid and accurate diagnosis depends on detection in the laboratory. This study aimed to establish a reliable and rapid method for accurate detection of FCoV, FPV, and FeLV so that a definite diagnosis can be made and effective measures can be taken to prevent and control viral infection.

Materials and Methods

We designed three pairs of specific primers and probes for the detection of FCoV 5' untranslated region, FPV viral protein 2, and FeLV pol genes. Recombinant plasmid constructs were generated for use as standard plasmid constructs. Optimal reaction conditions, including primer and probe concentrations, reaction cycles, and annealing temperatures, were obtained on the basis of optimization tests. One-step triplex real-time reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was successfully established to simultaneously detect FCoV, FPV, and FeLV. The specificity, sensitivity, and repeatability of the assay were analyzed, and its applicability was validated by testing 1175 clinical samples.

Results

One-step triplex RT-qPCR had a high degree of specificity only for the detection of FCoV, FPV, and FeLV; it had high sensitivity with limits of detection of 139.904, 143.099, and 152.079 copies/reaction for p-FCoV, p-FPV, and p-FeLV standard plasmid constructs, respectively, and it had reliable repeatability with 0.06%-0.87% intra-assay coefficients of variations. A total of 1175 clinical samples were examined for FCoV, FPV, and FeLV using triplex RT-qPCR, and the FCoV, FPV, and FeLV positivity rates were 18.47%, 19.91%, and 47.57%, respectively. The clinical sensitivity and specificity of one-step triplex RT-qPCR were 93.07% and 97.99%, respectively.

Conclusion

We developed a rapid and reliable one-step triplex RT-qPCR method for the detection of FCoV, FPV, and FeLV, which could be used as a diagnostic tool for clinical monitoring and diagnosis.

Viral metagenomic analysis reveals diverse viruses and a novel bocaparvovirus in the enteric virome of snow leopard (Panthera uncia)

The enteric virome, comprising a complex community of viruses inhabiting the gastrointestinal tract, plays a significant role in health and disease dynamics. In this study, the fecal sample of a wild snow leopard was subjected to viral metagenomic analysis using a double barcode Illumina MiSeq platform. The resulting reads were de novo assembled into contigs with SOAPdenovo2 version r240. Additional bioinformatic analysis of the assembled genome and genome annotation was done using the Geneious prime software (version 2022.0.2). Following viral metagenomic analysis and bioinformatic analysis, a total of 7 viral families and a novel specie of bocaparvovirus tentatively named Panthera uncia bocaparvovirus (PuBOV) with GenBank accession number OQ627713 were identified. The complete genome of PuBOV was predicted to contain 3 open reading frames (ORFs), contains 5433 nucleotides and has a G + C content of 47.40 %. BLASTx analysis and pairwise sequence comparison indicated the novel virus genome was a new species in the genus Bocaparvovirus based on the species demarcation criteria of the International Committee on the Taxonomy of Viruses. This study provides valuable insights into the diversity and composition of the enteric virome in wild endangered snow leopards. The identification and characterization of viruses in wildlife is crucial for developing effective strategies to manage and mitigate potential zoonotic and other viral disease threats to human and animal health.

Genetic characterization of the parvovirus full-length VP2 gene in domestic cats in Brazil

Feline parvovirus (FPV) and canine parvovirus (CPV) are over 98% identical in their DNA sequences, and the new variants of CPV (2a/2b/2c) have gained the ability to infect and replicate in cats. The aim of this study was to determine the genetic diversity in the VP2 gene of parvovirus strains circulating in domestic cats in Brazil during a 10-year period (2008-2017). For parvovirus screening, specific PCR was performed, and 25 (34.7%) of 72 cats tested positive. The PCR-positive samples were further subjected to full-length VP2 sequencing (1755 bp), and eight sequences (36%) were characterized as FPV, seven (28%) as CPV-2a and (32%) nine (36%) as CPV-2b. One sequence (RJ1085/11) showing typical CPV amino acid (aa) at residues 80 R, 93 N, 103 A, 232 I, and 323 N could not be characterized at this time. The sequences in this study displayed aa changes previously described for FPV (A14T, A91S, I101T, N564S, and A568G) from cats and CPV-2a/2b (S297N and Y324L) from dogs. However, the Y324L mutation has not yet been reported in any CPV-2a/2b strains from cats. Phylogenetic analysis supported the division of these sequences into two well-defined clades, clade 1 for FPV and clade 2 for CPV2a/2b. Unusually, the sequence RJ1085/11 was grouped separately. Two recombination breakpoints were detected by Bootscan and 3Seq methods implemented in the RDP4. This study is the first report of CPV-2a/2b in cats in Brazil. The detection of FPV strains with mutations characteristic of CPV indicates that Brazilian FPV strains have undergone genetic changes.

Protoparvovirus carnivoran 1 infection of golden jackals Canis aureus in Serbia

Parvoviruses are among the major animal pathogens that can cause considerable health disorders ranging from subclinical to lethal in domestic and wild animals. Golden jackal (Canis aureus), an expanding European species, is a reservoir of many pathogens, including vector-borne diseases and zoonoses. Given the importance of parvovirus infections in dogs and cats, this study aimed to unfold the virus prevalence and molecular characterisation in the golden jackal population in Serbia. The spleen samples from 68 hunted jackals during 2022/2023 were tested for the VP2-specific genome region of Protoparvovirus carnivoran 1 by PCR. BLAST analysis of partial VP2 sequences obtained from three animals (4.4%) revealed the highest similarity to Protoparvovirus carnivoran 1, genogroup Feline panleukopenia virus, which is the second report on FPV infection in jackals. Based on specific amino acid residues within partial VP2, the jackals' Protoparvovirus carnivoran 1 was also classified as FPV. One jackal's strain showed two synonymous mutations at positions 699 and 1167. Although species cross-transmission could not be established, jackals' health should be maintained by preventing the transmission of viruses to native species and vice versa. Although jackals are considered pests, their role as natural cleaners is of greater importance. Therefore, further monitoring of their health is needed to understand the influence of infectious diseases on population dynamics and to determine the relationship between domestic predators and jackals and the direction of cross-species transmission.

TaqMan-based real-time polymerase chain reaction for the detection of feline chaphamaparvovirus

Feline chaphamaparvovirus (FeChPV) is a new viral strain detected in Chinese Mainland in recent years. The symptoms mainly include diarrhea and bloody stool in young cats, which can lead to death in severe cases. In this study, a TaqMan-based real-time quantitative PCR (qPCR) with specific primers and TaqMan probes based on the VP1 gene sequence of FeChPV was performed to detect the virus. The established qPCR indicated that there is no cross-reaction of FeChPV with other common feline viruses. The minimum detection limit of the established qPCR method is 3.75 × 10 copies/µL, while conventional PCR is 3.75 × 103 copies/µL. The result that the proposed qPCR protocol was shown to be 100 times more sensitive than conventional PCR. The correlation coefficients exceeded 0.995, and the amplification efficiency was 98%. The difference within and between groups is less than 5%, indicating that the established method has good repeatability. The results of clinical sample detection shown that 16 positive samples were detected from 45 stool samples by the established qPCR method. The conventional PCR method only detected 3 positive samples. In conclusion, the established qPCR method is fast and effective in identifying FeChPV, with higher specificity and sensitivity. It could be used as a diagnostic tool to quantitatively detect the virus content, which is conducive to disease monitoring and epidemiological investigation.

Occurrence of Typical Domestic Animal Viruses in Wild Carnivorans: An Emerging Threat to the Conservation of Endangered Species

Wild species are susceptible to several typical domestic animal pathogens, and the increasingly close contact between these groups is a predictive factor for disease exposure. Some viruses are important and old-known, and others are emerging or reemerging for domestic carnivorans and have been identified as threats to the conservation of wild mammals. The purpose of the study was to investigate the occurrence of bocaparvoviruses (BoVs, Parvoviridae family, Parvovirinae subfamily, Bocaparvovirus genus), parvoviruses (Parvoviridae family, Parvovirinae subfamily, Protoparvovirus genus, Protoparvovirus carnivoran1), hepadnaviruses (Hepadnaviridae family), coronaviruses (Coronaviridae family, Orthocoronavirinae subfamily), paramyxoviruses (Paramyxoviridae family) and canine distemper virus (Orthoparamyxovirinae subfamily, Morbillivirus genus, Morbillivirus canis), poxviruses (Poxviridae family), feline herpesvirus (Orthoherpesviridae family, Alphaherpesvirinae subfamily, Varicellovirus genus, Varicellovirus felidalpha1), feline calicivirus (Caliciviridae family, Vesivirus genus, FCV), feline immunodeficiency virus (Retroviridae family, Orthoretrovirinae subfamily, Lentivirus genus, FIV), feline leukemia virus (Retroviridae family, Orthoretrovirinae subfamily, Gammaretrovirus genus, FeLV), and gammaherpesviruses (Orthoherpesviridae family, Gammaherpesvirinae subfamily) in wild carnivorans. A total of 30 biological samples from the families Canidae, Felidae, Mephitidae, Mustelidae, and Procyonidae were evaluated. All animals were victims of vehicular collisions in the state of Mato Grosso do Sul, Brazil. Canine parvovirus (CPV-2) DNA was detected in the spleen of a bush dog (Speothos venaticus), a jaguarundi (Puma yagouaroundi), and a jaguar (Panthera onca), FeLV proviral DNA was found in the spleen of an ocelot (Leopardus pardalis); while CDV RNA was detected in the liver of a jaguarundi. Phylogenetic analysis carried out with the partial sequence of the CPV-2 VP2 gene and the U3 (LTR) gag region of FeLV showed 100% identity with strains obtained from domestic dogs and cats, respectively. The approximation between wild and domestic animals favors the transmission of pathogens, especially between phylogenetically close species, such as members of the Canidae and Felidae families. Identification of the DNA and RNA of potentially fatal viruses such as CPV-2, FeLV, and CDV in four wilds endangered to extinction and understudied species contributes to our understanding of the pathogens circulating in this free-ranging and vulnerable population.

China-origin G1 group isolate FPV072 exhibits higher infectivity and pathogenicity than G2 group isolate FPV027

Introduction

Feline parvovirus (FPV), a single-stranded DNA virus, is accountable for causing feline panleukopenia, a highly contagious and often lethal disease that primarily affects cats. The epidemiology prevalence and pathogenicity of FPV in certain regions of China, however, remains unclear. The aim of this research was to investigate the epidemiology of FPV in different regions of China in 2021 and compare its infectivity and pathogenicity.

Methods

In this research, a total of 36 FPV strains were obtained from diverse regions across China. Phylogenetic analysis was performed based on the VP2 and NS1 sequences, and two representative strains, FPV027 and FPV072, which belonged to different branches, were selected for comparative assessment of infectivity and pathogenicity.

Results and discussion

The results revealed that all strains were phylogenetically classified into two groups, G1 and G2, with a higher prevalence of G1 strains in China. Both in vitro and in vivo experiments demonstrated that FPV072 (G1 group) exhibited enhanced infectivity and pathogenicity compared to FPV027 (G2 Group). The structural alignment of the VP2 protein between the two viruses revealed mutations in residues 91, 232, and 300 that may contribute to differences in infectivity and pathogenicity. The findings from these observations will contribute significantly to the overall understanding of the molecular epidemiology of FPV in China and facilitate the development of an effective FPV vaccine.

Prevalence and Molecular Evolution of Parvovirus in Cats in Eastern Shandong, China, between 2021 and 2022

Feline panleukopenia (FPL) is a highly contagious infectious disease caused by infection with feline parvovirus (FPV) and canine parvovirus type 2 (CPV-2). In recent years, the number of cats with FPL has increased with the expansion of pet cat population in China. The feces of 51 cats with diarrhea symptoms collected from 2021 to 2022 in Eastern Shandong, China, were detected by polymerase chain reaction for parvovirus and other viruses related to feline diarrhea to investigate the prevalence and gene variation of parvovirus in cats. In all the 51 samples, 45.1% (23/51) were positive for at least one viral pathogen, and the positivity of parvovirus was 41.2% (21/51), showing a high prevalence. Multiple-pathogen testing indicated high-coinfection rates of 42.9% (9/21) with other common viruses in parvovirus-positive cats. Most of the coinfections are feline coronavirus (FCoV), followed by feline astrovirus (FAstV) and feline bocavirus (FBoV). The complete VP2 sequences of 21 parvoviruses were obtained. Among them, 20 sequences were identified as FPV, and only one was CPV-2c of Asian origin, which was first detected from cats in Eastern Shandong, China. A phylogenetic tree of the 20 FPVs was constructed together with 698 FPVs (cat/dog host) worldwide on the basis of complete VP2. The 18 FPVs displayed high-sequence identity to one another (99.8%-100%), and they were clustered into FPV-G1 group, whereas the other two were clustered into FPV-G3 group. The FPV-G1 group increased dramatically to become predominant after 2019 in China, contributing to the prevalence of A91S mutation due to 96.07% FPV-G1 with A91S mutation as well as 100% of FPV-G2 and 99.12% of FPV-G3 with 91A in the statistical analysis. This study enriched the understanding of the prevalence, molecular evolution, and cross-species transmission of parvovirus in cats and provided a basis for responding to challenges in the diagnosis and treatment of FPL.

Prevalence of Serum Antibody Titers against Core Vaccine Antigens in Italian Cats

Feline core vaccines strongly recommended for all cats are against Feline panleukopenia virus (FPV), Felid herpesvirus type 1 (FeHV-1), and Feline calicivirus (FCV), but cats can be classified as low- and high-risk based on their lifestyle. The aim of this study was to determine the actual seroprotection against FPV, FeHV-1, and FCV in a large cohort of Italian cats by using the VacciCheck test. A total of 740 cats (567 owned and 173 stray cats; 435 vaccinated and 305 unvaccinated) were analyzed for Protective Antibody Titers (PATs). Differences related to origin, sex, age, breed, FIV/FeLV status, health status, and time elapsed since last vaccination were evaluated. Less than half of the entire cohort (36.4%) had PATs for all three diseases simultaneously, increasing to 48.6% if weak positive values were also considered and 50.3% when considering only the 435 vaccinated cats. Particularly, antibodies were detected against FCV, FPV, and FeHV-1 at protective titers (PATs) in 78.6%, 68.1, and 49.1% of the cats, respectively. In general, owned, neutered, and adult FIV- and/or FeLV-negative cats were the most protected categories, even if not always for the three viruses. Most cats maintained high PATs for 3 years or longer after vaccination against FPV and FCV but not FeHV-1. Long-lasting protective immunity persisted for many years after the last vaccination (more than 18 years in the oldest cats). Nevertheless, since not all cats were protected after so many years and for all pathogens, checking protection via antibody titration could be the best choice to prevent immunity breakdowns. The discussion also focuses on the reliability of antibody titration for the two URTD (upper respiratory tract disease) viruses which, unlike for FPV, is not widely accepted as a valid index of protection.

Impact of the Application of Gaseous Ozone on Selected Pathogens Found in Animal Shelters and Other Facilities

Correctly selecting disinfection procedures is crucial in facilities housing a high number of animals as it directly affects their health. The aim of this study was to verify the virucidal effect of gaseous ozone delivered by commercially available generators under controlled experimental conditions on a selection of viral pathogens (feline coronavirus, canine coronavirus, feline calicivirus, feline parvovirus) commonly found in shelters and other facilities. Two ozone generators with outputs of 3.5 g/h and 20 g/h were used to produce ozone. Virus viability after the application of ozone was evaluated by examining for typical pathogen-specific cytopathic effects on the CRFK (Crandell-Rees Feline Kidney) cell line post-incubation. No cytopathic effect was observed in feline coronavirus after the 2-h application of ozone; in canine coronavirus, the absence of a cytopathic effect was observed after the 4-h application of ozone. The absence of a cytopathic effect in feline calicivirus was observed after the 6-h application of ozone; the viability of feline parvovirus was not impaired even by the 6-h application of ozone. The results of the study confirm lower resistance to the application of gaseous ozone in enveloped viruses.

Characterization of a fatal feline panleukopenia virus derived from giant panda with broad cell tropism and zoonotic potential

Represented by feline panleukopenia virus (FPV) and canine parvovirus (CPV), the species carnivore protoparvovirus 1 has a worldwide distribution through continuous ci13rculation in companion animals such as cats and dogs. Subsequently, both FPV and CPV had engaged in host-to-host transfer to other wild animal hosts of the order Carnivora. In the present study, we emphasized the significance of cross-species transmission of parvoviruses with the isolation and characterization of an FPV from giant panda displaying severe and fatal symptoms. The isolated virus, designated pFPV-sc, displayed similar morphology as FPV, while phylogenetic analysis indicated that the nucleotide sequence of pFPV-sc clades with Chinese FPV isolates. Despite pFPV-sc is seemingly an outcome of a spillover infection event from domestic cats to giant pandas, our study also provided serological evidence that FPV or other parvoviruses closely related to FPV could be already prevalent in giant pandas in 2011. Initiation of host transfer of pFPV-sc is likely with association to giant panda transferrin receptor (TfR), as TfR of giant panda shares high homology with feline TfR. Strikingly, our data also indicate that pFPV-sc can infect cell lines of other mammal species, including humans. To sum up, observations from this study shall promote future research of cross-host transmission and antiviral intervention of Carnivore protoparvovirus 1, and necessitate surveillance studies in thus far unacknowledged potential reservoirs.

Molecular characterization and genetic diversity of parvoviruses prevalent in cats in Central and Eastern China from 2018 to 2022

Cats are a potential source of genetic diversity for parvoviruses. Herein, 134 samples were collected from cats with clinical gastroenteritis and analyzed for the presence of viral DNA via polymerase chain reaction, which revealed 48 positive samples. Identity analysis of VP2 nucleotide sequences indicated that these 48 strains, belonging to feline panleukopenia virus (FPV) and canine parvovirus type-2 (CPV-2; including new CPV-2a and CPV-2c genotypes), shared 94.59-99.94% nucleotide identity with the reference strains. The FPV strain F8 (isolated from Vietnam) appeared to be a recombinant of strains HB2003 and JS1901, whereas the Chinese CPV-2b strain BM-(11) isolated in 2011 was believed to be a recombinant of strains AH2008 and JS1901. In phylogenetic tree analysis based on VP2 nucleotide sequences, all obtained FPV strains and most reference FPV strains were clustered together, except strain BJ-22, which originated from monkeys. Further, two new CPV-2a strains (AH2005 and AH2008) were close to the newly reported Chinese CPV-2a strains but were distant from the other CPV-2a strains, namely CPV-339 (from the United States) and K022 (from South Korea). Additionally, the FPV and CPV-2 strains had high mutation rates in the antigenic regions of the VP2 protein. According to model prediction of the CPV-VP2 protein, these mutations may cause changes in the tertiary structure of VP2. The findings of this study can be used to improve the pre-evaluation of vaccination efficacy against diseases caused by FPV and CPV-2 in domestic cats and understand their genotypic transmission and mutation trends.

Evaluation of the Inactivation Efficacy of Four Disinfectants for Feline Parvovirus Derived from Giant Panda

Feline panleukopenia (FPL) is a highly contagious acute infectious disease caused by feline parvovirus (FPV). FPV has also been found in giant pandas with clinical signs of vomiting and mild diarrhea, posing a threat to this vulnerable species. Cleaning and disinfection may be one of the most efficacious ways to prevent FPV spread in the habitat of giant pandas. This study evaluated the inactivation effect of peracetic acid (PAA), povidone-iodine (PVP-I), glutaral and deciquam solution (JM) and Virkon S. The tissue culture infective dose (TCID₅₀) assay indicated that the virus may be totally inactivated by JM, PAA and Virkon S. Meanwhile, the hemagglutination (HA) assay showed a high inactivation efficiency of PAA and Virkon S. The analysis of Western blot revealed that PAA, Virkon S and JM can inhibit the structural protein synthesis. Taken together, our findings demonstrated that PAA could rapidly and efficiently inactivate FPV, representing an efficacious disinfectant for FPV control.

Feline Parvovirus Lethal Outbreak in a Group of Adult Cohabiting Domestic Cats

Feline panleukopenia is a highly contagious and often fatal disease in cats. The virus, known as feline panleukopenia virus (FPV), primarily affects kittens and unvaccinated cats. It is transmitted through contact with infected cats or their bodily fluids, as well as contaminated objects and environments. The diagnosis of FPV infection can be confirmed through a combination of clinical signs, blood tests, and fecal testing. Prevention through vaccination is recommended for all cats. This case report describes an outbreak of feline panleukopenia in a group of unvaccinated domestic cats that resulted in acute mortality. The lesions were evaluated using histopathology, and the specific viral strain was characterized using molecular techniques. The clinical course of the outbreak was peracute, with a hemorrhagic pattern and 100% of lethality. The observed clinical-pathological pattern was unusual; nevertheless, molecular studies did not highlight peculiar genomic features of the parvovirus isolate. The outbreak affected 3 out of 12 cats in a very short time. However, the prompt application of biosecurity measures and vaccination resulted in an effective interruption of virus spread. In conclusion, we could assume that the virus found the ideal conditions to infect and replicate at high titers, resulting in a particularly aggressive outbreak.

Exploring the Enteric Virome of Cats with Acute Gastroenteritis

Viruses are a major cause of acute gastroenteritis (AGE) in cats, chiefly in younger animals. Enteric specimens collected from 29 cats with acute enteritis and 33 non-diarrhoeic cats were screened in PCRs and reverse transcription (RT) PCR for a large panel of enteric viruses, including also orphan viruses of recent identification. At least one viral species, including feline panleukopenia virus (FPV), feline enteric coronavirus (FCoV), feline chaphamaparvovirus, calicivirus (vesivirus and novovirus), feline kobuvirus, feline sakobuvirus A and Lyon IARC polyomaviruses, was detected in 66.1% of the samples.. Co-infections were mainly accounted for by FPV and FCoV and were detected in 24.2% of the samples. The virome composition was further assessed in eight diarrhoeic samples, through the construction of sequencing libraries using a sequence-independent single-primer amplification (SISPA) protocol. The libraries were sequenced on Oxford Nanopore Technologies sequencing platform. A total of 41 contigs (>100 nt) were detected from seven viral families infecting mammals, included Parvoviridae, Caliciviridae, Picornaviridae, Polyomaviridae, Anelloviridae, Papillomaviridae and Paramyxoviridae, revealing a broad variety in the composition of the feline enteric virome.

Identification and Genome Characterization of Novel Feline Parvovirus Strains Isolated in Shanghai, China

Feline panleukopenia virus (FPV) is the causative agent of hemorrhagic gastroenteritis in feline animals. FPV has been evolving over time, and there have been several different strains of the virus identified. Some of these strains may be more virulent or more resistant to current vaccines than others, which highlights the importance of ongoing research and monitoring of FPV evolution. For FPV genetic evolution analysis, many studies focus on the main capsid protein (VP2), but limited information is available on the nonstructural gene NS1 and structural gene VP1. In the present study, we firstly isolated two novel FPV strains circulating in Shanghai, China, and performed full-length genome sequencing for the desired strains. Subsequently, we focused on analyzing the NS1, VP1 gene, and the encoding protein, and conducted a comparative analysis among the worldwide circulating FPV and Canine parvovirus Type 2 (CPV-2) strains, which included the strains isolated in this study. We found that the 2 structural viral proteins, VP1 and VP2, are splice variants, and VP1 has a 143 amino-acid-long N-terminal compared to VP2. Furthermore, phylogenetic analysis showed that divergent evolution between FPV and CPV-2 virus strains were clustered mostly by country and year of detection. In addition, much more continuous antigenic type changes happened in the process of CPV-2 circulating and evolution compared to FPV. These results stress the importance of the continuous study of viral evolution and provide a comprehensive perspective of the association between viral epidemiology and genetic evolution.

Disease threats to tigers and their prey

The contraction of the global tiger population over the last 100 years into small, often isolated subpopulations has made them increasingly vulnerable to the impact of disease. Despite this, the health of wild tigers continues to be insufficiently funded and explored. For example, canine distemper virus (CDV), has been associated with localized declines and increased risk of extinction, and yet has received little research attention in most tiger range countries. The emergence of new pathogenic threats has posed fresh challenges, including African swine fever virus (ASFV), which has the potential to devastate wild boar populations, and severe acute respiratory syndrome coronavirus (SARS-CoV2) with implications for tiger conservation that remain unknown. The objective of this review is to synthesize current research on the health of tigers and their prey that impacts the conservation of tigers in the wild. Published sources are interpreted based on three mechanisms through which disease can affect the viability of tiger populations: (1) by reducing the survival of adult tigers, (2) by reducing breeding productivity, and (3) by reducing the carrying capacity of tiger habitat through decreased prey abundance. Examples of CDV, SARS-CoV2, carnivore protoparvovirus 1 and ASFV are used to illustrate these processes and inform discussion of research and mitigation priorities.

[Parvovirus infections in cats in animal shelters]

Due to widespread vaccination programs against feline panleukopenia virus (FPV), the disease associated with this virus infection, feline panleukopenia, is rarely seen in privately owned cats in Germany. In contrast, the situation in animal shelters differs due to the constant intake of new cats that are often unprotected. In such facilities, panleukopenia outbreaks are common and often accompanied by a high number of fatalities. Due to the high contagiosity of the virus, some shelters do not accept cats with clinical signs suspicious for panleukopenia, since these animals can pose a risk to the shelter population. However, not only cats with panleukopenia shed parvovirus, but also healthy, asymptomatic cats can and thus contribute to risk of infection. Nevertheless, the risk for panleukopenia outbreaks in animal shelters can be reduced by rigorous outbreak management. This includes hygiene measures using correctly applied cleaning and disinfection protocols, quarantine measures, separate isolation units, as well as specific prophylactic measures, such as identification of infected animals and immunization of susceptible groups.

Clinico-epidemiological survey of feline parvovirus circulating in three Egyptian provinces from 2020 to 2021

Feline parvovirus infection, caused by feline parvovirus and canine parvovirus 2, is a highly contagious, life-threatening disease affecting cats. The available epidemiological data on parvovirus infection in cats in Egypt is limited. Therefore, the aim of the current study was to provide data concerning the epidemiological profile of cats infected with parvovirus, including the prevalence of parvovirus infection in cats in three Egyptian provinces (Sohag, Assiut, and Cairo) and the associated risk factors. Using rapid antigen tests of fecal samples and conventional PCR, the overall prevalence of parvovirus infection in cats was found to be 35% (35/100) and 43% (43/100), respectively. Anorexia, bloody diarrhea, severe dehydration, hypothermia, and vomiting were the most common clinical findings significantly associated with parvovirus-infected cats. The geographical location (Sohag) and the season (winter) were both statistically significant risk factors for parvovirus infection. These findings indicate that parvoviruses are circulating in different regions of Egypt. Our study provides baseline epidemiological data for future preventive and control measures against parvovirus infection, as well as highlighting the need for future genomic surveillance studies involving a large study population from various parts of Egypt in order to better shape the epidemiological picture of parvovirus infection.

Feline Susceptibility to Leptospirosis and Presence of Immunosuppressive Co-Morbidities: First European Report of L. interrogans Serogroup Australis Sequence Type 24 in a Cat and Survey of Leptospira Exposure in Outdoor Cats

Leptospirosis is one of the most widespread zoonotic diseases and can infect both humans and animals worldwide. The role of the cat as a susceptible host and potential environmental reservoir of Leptospira is still not well understood, due to the lack of obvious clinical signs associated with Leptospira spp. infection in this species. This study aims to describe the first European detection of Leptospira interrogans serogroup Australis ST 24 in a young outdoor cat with a severe comorbidity (feline panleukopenia virus). In addition, the results of a preliminary study conducted in 2014-2016 are presented (RC IZSVE 16/12), which reports an investigation of Leptospira exposure of outdoor cats in Northeast Italy by means of serological investigation and molecular evaluation of urine. The animals included in the survey are part of samples collected during active and passive surveillance (diagnostic samples). The study reported a seroprevalence of 10.5% among outdoor cats and the serogroups identified were Grippotyphosa, Icterohaemorrhagiae, Bratislava, Canicola and Ballum. Symptomatic cats reported high MAT titres (ranging from 1:800 to 1:1600) towards antigens belonging to the serovars Grippotyphosa (1:800), Bratislava (1:1600), Icterohaemorrhagiae (1:200) and Copenhageni (1:200-1:800). In one subject, urine tested positive for Leptospira PCR. Cats with high antibody titres for Leptospira and/or positivity on molecular test suffered from immunosuppressive comorbidities (feline immunodeficiency virus and feline leukaemia virus; feline herpesvirus and lymphoma; hyperthyroidism). The overall prevalence of serum antibodies against Leptospira found in free-ranging cats (10.53%, 95% CI: 4.35-16.70%) and the identification of L. interrogans ST 24 in a young cat with immunosuppressive disease (feline panleukopenia virus) suggest the possibility of natural resistance to clinical leptospirosis in healthy cats. In a One Health perspective, further studies are needed to better define the pathogenesis of leptospirosis in cats and their epidemiological role as environmental sentinels or possible carriers of pathogenic Leptospira.

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.

Clinical and clinicopathological features and outcomes of cats with suspected dietary induced pancytopenia

BACKGROUND

After a strong epidemiological link to diet was established in an outbreak of pancytopenia in cats in spring 2021 in the United Kingdom, 3 dry diets were recalled. Concentrations of the hemato- and myelotoxic mycotoxins T-2, HT-2 and diacetoxyscirpenol (DAS) greater than the European Commission guidance for dry cat foods were detected in the recalled diets.

OBJECTIVES

To describe clinical and clinicopathological findings in cats diagnosed with suspected diet induced pancytopenia.

ANIMALS

Fifty cats presenting with pancytopenia after exposure to a recalled diet.

METHODS

Multicenter retrospective case series study. Cats with known exposure to 1 of the recalled diets were included if presented with bi- or pancytopenia and underwent bone marrow examination.

RESULTS

Case fatality rate was 78%. Bone marrow aspirates and biopsy examination results were available in 23 cats; 19 cats had a bone marrow aspirate, and 8 cats had a biopsy core, available for examination. Bone marrow hypo to aplasia-often affecting all cell lines-was the main feature in all 31 available core specimens. A disproportionately pronounced effect on myeloid and megakaryocytic cells was observed in 19 cats. Myelofibrosis or bone marrow necrosis was not a feature.

CONCLUSION AND CLINICAL IMPORTANCE

Mycotoxin induced pancytopenia should be considered as differential diagnosis in otherwise healthy cats presenting with bi- or pancytopenia and bone marrow hypo- to aplasia.

The morbidity and the spectrum of applied drugs in shelter cats in the Czech Republic

Maintaining appropriate living conditions and good health of the animals should be one of the main priorities of cat shelters. The aim of this study was to assess the morbidity of shelter cats on the basis of analysis of the shelter health records in terms of the nature and quantity of medicaments and other supportive products administered in two no-kill shelters in the Czech Republic. The subject of the study were the health records of 1,884 cats, which were admitted to the selected shelters from 1.1.2013 to 31.12.2021 and their stay in the shelter was terminated in the monitored period. More than half of all cats whose records were analyzed had at least one health record made during their stay in the shelter. The overall length of stay of cats in the shelter (regardless of the outcome) in which one or more health records were found was significantly longer compared to the length of stay of cats without any health records. The highest number of health records was found in kittens <6 months old. Antibiotics, antiparasitics, and complementary/protective substances were the most used among all administered drugs. Broad-spectrum antibiotics have been administered to cats most often. In terms of classification of antibiotics according to the active substance, the most used antibiotics were penicillins, tetracyclines, and fluoroquinolones. Antibiotics were mostly used to treat diseases related to the upper and lower respiratory tract and their symptoms and gastrointestinal problems. The findings of the study contribute to understanding health problems and approaches to treating the shelter cats.

A Retrospective Study of Viral Molecular Prevalences in Cats in Southern Italy (Campania Region)

From 2019 to 2021, a retrospective molecular study was conducted in the Campania region (southern Italy) to determine the prevalence of viral diseases in domestic cats. A total of 328 dead animals were analyzed by Real-Time PCR for the presence of feline panleukopenia virus (FPV), feline leukemia virus (FeLV), feline enteric coronavirus (FCoV), rotavirus (RVA), feline herpesvirus type 1 (FHV-1), and feline calicivirus (FCV). The possible presence of SARS-CoV-2 was also investigated by Real-Time PCR. The cats included in this study were specifically sourced and referred by local veterinarians and local authorities to the Zooprofilactic Experimental Institute of Southern Italy (IZSM) for pathological evaluation. The samples consisted of owners, catteries, and stray cats. Results revealed: 73.5% positive cats for FPV (189/257), 23.6% for FeLV (21/89), 21.5% for FCoV (56/266), 11.4% for RVA (16/140), 9.05% for FeHV-1 (21/232), and 7.04 for FCV (15/213). In contrast, SARS-CoV-2 was never detected. FPV was more prevalent in winter (p = 0.0027). FCoV FHV-1, FCV, and RVA predominated in autumn, whereas FeLV predominated in summer. As expected, viral infections were found more frequently in outdoor and shelter cats than in indoor ones, although no statistical association was found between animal lifestyle and viral presence. The study showed a high prevalence of FPV, FeLV, and FCoV and a moderate prevalence of RVA, FHV-1, and FCV. Moreover, the prevalence of these pathogens varied among the cat populations investigated.

Development of a TaqMan-based multiplex real-time PCR for simultaneous detection of four feline diarrhea-associated viruses

Since their recent discovery, the prevalence of novel feline enteric viruses, including feline bocavirus 1 (FBoV-1), feline astrovirus (FeAstV), and feline kobuvirus (FeKoV), has been reported in China. Co-infections of these viruses with feline parvovirus (FPV) are common causes of diarrhea in cats. Viral co-infections are difficult to identify because of their non-specific clinical signs. To detect and identify these viruses, a quick and specific pathogen-testing approach is required. Here, we establish a real-time PCR (qPCR) based on multiple TaqMan probes for the simultaneous detection of FBoV-1, FeAstV, FeKoV, and FPV. Specific primers and TaqMan fluorescent probes were designed to ensure specificity. The results showed that the detection limit of single qPCR was up to 10 copies, and the detection limit of multiplex qPCR was up to 100 copies, with correlation coefficients >0.995 in all cases. Clinical sample detection revealed a 25.19% (34/135) total rate of co-infection among the viruses and a 1.48% (2/135) quadruple infection rate. Thus, this multiplex qPCR approach can serve as a quick, sensitive, and specific diagnostic tool for FBoV-1, FeAstV, FeKoV, and FPV identification, and it may be utilized for routine surveillance of these emerging and reemerging feline enteric viruses.

Development of a triple NanoPCR method for feline calicivirus, feline panleukopenia syndrome virus, and feline herpesvirus type I virus

Background

Feline calicivirus (FCV), Feline panleukopenia virus (FPV), and Feline herpesvirus type I (FHV-1) are the three most common pathogens in cats, and also are the main pathogens leading to the death of kittens. Here, by a combination of gold nanoparticles and conventional PCR, we established a novel triple NanoPCR molecular detection method for clinical detection.

Results

The triple NanoPCR molecular detection is able to detect 2.97 × 10¹copies/μL FCV recombinant copies plasmid per reaction, 2.64 × 10⁴copies/μL FPV recombinant copies plasmid per reaction, and 2.85copies/μL FHV-1 recombinant copies plasmid per reaction at the same time. The sensitivity of each plasmid is 100 times, 10 times, and 100 times higher than conventional PCR, respectively. The clinical results showed that among the 38 samples, the positive rates of FCV, FPV, and FHV-1 in a NanoPCR test were 63.16, 31.58, and 60.53%, while in a conventional PCR were 39.47, 18.42, and 34.21%.

Conclusions

In this report, it is the first time that NanoPCR assays are applied in the detection of FCV, FPV, and FHV-1 as well. This sensitive and specific NanoPCR assay can be widely used in clinical diagnosis and field monitoring of FCV, FPV, and FHV-1 infections.

The natural cytotoxicity receptor (NCR) genes in the family Felidae

Natural killer (NK) cells belong to the innate immune system. The germline-encoded natural killer cell receptors represent activating and inhibitory receptors regulating multiple NK cell activities. The natural cytotoxicity receptors (NCRs) are activating natural cytotoxicity triggering receptors 1, 2 and 3 (NKp46, NKp44, and NKp30), encoded by the genes NCR1, NCR2, and NCR3, respectively. NCRs may be expressed in different cell types engaged in mechanisms of innate and adaptive immunity. The family Felidae, comprising the domestic cat and a wide variety of free-ranging species represents a well-suited model for biomedical and evolutionary studies. We characterized the NCR1, NCR2 and NCR3 genes in a panel of felid species. We confirmed the presence of potentially functional genes NCR1, NCR2 and NCR3 in all species. All three genes are conserved within the family and are similar to other phylogenetically related mammalian families. The NCR1 and NCR2 phylogenetic trees based on both nucleotide and protein sequences corresponded to the current zoological taxonomy, with some exceptions suggesting effects of different selection pressures in some species. Highly conserved NCR3 sequences did not allow a robust phylogenetic analysis. Most interspecific differences both at the nucleotide and protein level were found in NCR2. Within species, the most polymorphic CDS was detected in NCR1. Selection analyses indicated the effects of purifying selection on individual amino acid sites in all three genes. In stray cats, a rather high intraspecific diversity was observed. This article is protected by copyright. All rights reserved.

The enteric virome of cats with feline panleukopenia differs in abundance and diversity from healthy cats

Feline panleukopenia (FPL) is a severe, often fatal disease caused by feline panleukopenia virus (FPV). How infection with FPV might impact the composition of the entire eukaryotic enteric virome in cats has not been characterized. We used meta-transcriptomic and viral particle enrichment metagenomic approaches to characterize the enteric viromes of 23 cats naturally infected with FPV (FPV-cases) and 36 age-matched healthy shelter cats (healthy controls). Sequencing reads from mammalian infecting viral families largely belonged to the Coronaviridae, Parvoviridae and Astroviridae. The most abundant viruses among the healthy control cats were feline coronavirus, Mamastrovirus 2 and Carnivore bocaparvovirus 3 (feline bocavirus), with frequent coinfections of all three. Feline chaphamaparvovirus was only detected in healthy controls (6 out of 36, 16.7%). Among the FPV-cases, in addition to FPV, the most abundant viruses were Mamastrovirus 2, feline coronavirus and C. bocaparvovirus 4 (feline bocaparvovirus 2). The latter and feline bocaparvovirus 3 were detected significantly more frequently in FPV-cases than in healthy controls. Feline calicivirus was present in a higher proportion of FPV-cases (11 out of 23, 47.8%) compared to healthy controls (5 out of 36, 13.9%, p = 0.0067). Feline kobuvirus infections were also common among FPV-cases (9 out of 23, 39.1%) and were not detected in any healthy controls (p < .0001). While abundant in both groups, astroviruses were more frequently present in FPV-cases (19 out of 23, 82.6%) than in healthy controls (18 out of 36, p = .0142). The differences in eukaryotic virome composition revealed here indicate that further investigations are warranted to determine associations between enteric viral co-infections on clinical disease severity in cats with FPL.

Low Intrahost and Interhost Genetic Diversity of Carnivore Protoparvovirus 1 in Domestic Cats during a Feline Panleukopenia Outbreak

Feline panleukopenia (FPL), a highly contagious and frequently fatal disease of cats, is caused by Feline parvovirus (FPV) and Canine parvovirus (CPV). We characterised the diversity of these Carnivore protoparvovirus 1 variants in 18 faecal samples collected from domestic cats with FPL during an outbreak, using targeted parvoviral DNA metagenomics to a mean depth of >10,000 × coverage per site. All samples comprised FPV alone. Compared with the reference FPV genome, isolated in 1967, 44 mutations were detected. Ten of these were nonsynonymous, including 9 in nonstructural genes and one in VP1/VP2 (Val232Ile), which was the only one to exhibit interhost diversity, being present in five sequences. There were five other polymorphic nucleotide positions, all with synonymous mutations. Intrahost diversity at all polymorphic positions was low, with subconsensus variant frequencies (SVF) of <1% except for two positions (2108 and 3208) in two samples with SVF of 1.1−1.3%. Intrahost nucleotide diversity was measured across the whole genome (0.7−1.5%) and for each gene and was highest in the NS2 gene of four samples (1.2−1.9%). Overall, intrahost viral genetic diversity was limited and most mutations observed were synonymous, indicative of a low background mutation rate and strong selective constraints.

Circulation of heterogeneous Carnivore protoparvovirus 1 in diarrheal cats and prevalence of an A91S feline panleukopenia virus variant in China

Cats are susceptible to panleukopenia virus (FPV) and canine parvovirus type 2 (CPV-2) infection. FPV has been recognized as relatively conservative in genetic evolution compared to CPV-2, but information regarding FPV variations in cats are still limited. The aim of this study was to investigate the molecular prevalence of FPV and CPV-2 variants among cats in China. From April 2019 to December 2021, 193 diarrheal fecal samples of cats were collected from Southwest China and 127 (65.80 %) samples tested positive to Carnivore protoparvovirus 1. FPV, CPV-2 and some their genomic variants were identified from positive samples, indicating a heterogeneous Carnivore protoparvovirus 1 circulation in the cat population in China. Among FPV strains, an A91S FPV mutant reached the detection rate of 39.37 %, which showed that this FPV genomic variant has been prevalent in the tested cats. Moreover, 7 strains of A91S FPV variants were isolated and purified successfully using F81 cells, and the genomes were sequenced. Phylogenetic trees based on the nearly complete genomic sequences, VP2 and NS1 nucleotide sequences showed that the A91S FPV variants were located in the FPV clade, but all clustered into a separate branch. Structural prediction showed that A91S mutation in VP2 protein extended the random coil of aa residues from 92-95 to 91-95. Moreover, the analysis of all complete VP2 sequences of FPV and CPV-2 available in the GenBank database revealed that the A91S FPV variant has been prevalent in China since 2017 and has reported in four other countries in cats. Thus, our study revealed that heterogeneous Carnivore protoparvovirus 1 are circulating in the cat population in China, and first reported the prevalence and genomic characteristics of the A91S FPV variant, which contributed to a better understanding of the molecular prevalence and genetic evolution of FPV in cats. This article is protected by copyright. All rights reserved.

Feline Panleukopenia Outbreaks and Risk Factors in Cats in Animal Shelters

(1) Background: This study aimed to determine the risk factors for outbreaks of feline panleukopenia in shelters. (2) Methods: Four shelters (A−D) with 150 cats were included. Fecal samples were analyzed by parvovirus real-time polymerase chain reaction (qPCR), including culture and sequencing of qPCR-positive samples. Information on cats, husbandry, hygiene, and infection management was evaluated to determine risk factors for feline panleukopenia and parvovirus shedding by logistic regression. (3) Results: Feline panleukopenia occurred in 28.0% (42/150) of cats (0 in shelter D). Shedding was found in 48.7% (73/150) (A: 21/73; B: 29/73; C: 7/73; D: 16/73). Of 73 qPCR-positive fecal samples, 65.8% (48/73) were culture-positive; sequencing revealed feline panleukopenia virus (FPV) isolates in 34/48 samples and vaccine virus isolate in 14/48; canine parvovirus was not detected. Presence of feline panleukopenia was significantly more likely in cats from shelter A (p < 0.05), unvaccinated cats (p < 0.001), and young cats (4 weeks to 2 years; p = 0.008). Parvovirus shedding was significantly more common in young cats (p < 0.001), cats with feline panleukopenia (p = 0.033), and group-housed cats (p = 0.025). (4) Conclusions: Vaccination is the most important measure to reduce the risk of feline panleukopenia in shelters. Risk of parvovirus shedding is especially high in young, group-housed cats.