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Objective: The purpose of this study was to identify knowledge gaps in the global prevalence of feline immunodeficiency virus (FIV) and to obtain professional opinions and experiences regarding FIV in selected countries. We conducted a literature review of abstracts that reported the prevalence of FIV and interviewed experts in feline medicine and retroviruses from different countries to determine regional perspectives., Methods: A total of 90 articles reporting FIV prevalence as a primary unbiased population-level analysis between 1980 and 2017 were indexed. FIV prevalence, demographics, year and location were analyzed. Statistics were evaluated and compared. In total, 10 experts were interviewed. Results were analyzed for congruence with the findings of the literature review., Results: FIV prevalence was typically in the range of 5-8%, with a global prevalence of 4.7%, and remained largely constant over the reporting period (1980-2017). Over 90% of articles reported greater prevalence in older male cats. More studies were conducted in North America and Europe and reported the lowest prevalence. Expert-estimated prevalence approximated literature review prevalence. Attitudes and recommendations for management were consistent among experts. The limitations of the present review include varying inclusion criteria of cats tested in different studies, variation in testing modalities and the inability to conduct summary statistics across dissimilar cohorts., Conclusions and Relevance: The global prevalence of FIV has not changed since its discovery 40 years ago. Prevalence is higher in older male cats and is lower in North America and Europe than other continents. Experts agree that FIV is not typically a disease of high concern and is often associated with infections of the oral cavity. Vaccination is not typically recommended and has been discontinued in North America. The evaluation of risk factors for FIV progression is useful in managing infections. Recommendations for future research include analyses to determine copathogen and environmental factors that impact progression, assessment of life span impacts and investigations of treatment efficacy and side effects., Competing Interests: Conflict of interestThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

The utility of neutrophil-lymphocyte ratio (NLR), monocyte-lymphocyte ratio (MLR), and platelet-lymphocyte ratio (PLR) as prognostic markers in Feline Leukemia Virus (FeLV) and Feline Immunodeficiency Virus (FIV) infections has not yet been investigated. The aim of this study was to investigate these leukocyte ratios in retrovirus-positive cats and to evaluate their prognostic value for survival. This retrospective case-control study included 142 cats, 75 FIV-Antibodies (Ab)-positive, 52 FeLV-Antigen (Ag)-positive, and 15 FIV-Ab+FeLV-Ag-positive, and a control population of 142 retrovirus-negative age-, sex-, and lifestyle-matched cats. Signalment, complete blood count at the time of serological testing, and outcome were recorded. Leukocyte ratios were compared within the same case-control population, among the three retrovirus-seropositive populations, and were related to survival time. No significant difference was found in NLR, MLR, or PLR between FIV-Ab-positive and FIV-Ab+FeLV-Ag-positive cats and their cross-matched controls. In the FeLV-Ag-positive population, MLR was significantly lower than in the control population (0.05 and 0.14, respectively, P=0.0008). No ratio discriminated among the three infectious states. No ratio was significantly different between survivors and non-survivors in the population of FIV-Ab-positive cats. MLR at diagnosis was significantly higher in FeLV-Ag-positive cats that died 1-3 years after diagnosis than in FeLV-Ag-positive cats still alive at 3 years (P=0.0284). None of the three ratios could predict retroviruses-positive cats that would survive to the end of the study. Overall the results indicate that NLR, MLR, and PLR are not significantly different among retrovirus statuses evaluated and had a very limited prognostic value for the survival time in retrovirus-positive cats., Competing Interests: Conflict of interest None of the authors has any financial or personal relationships that could inappropriately influence or bias the content of the paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) are retroviruses of great importance for domestic cats with a worldwide distribution. A retrospective study was conducted to determine the epidemiological and clinicopathological aspects of the infection by FIV and FeLV in cats from the Brazilian semiarid region. Cats treated between 2011 and 2021 at the teaching veterinary hospital of the Federal Rural University of the Semi-Arid Region that were submitted to a point-of-care (POC) test to detect anti-FIV IgG antibodies and FeLV antigen were enrolled in the study. Overall, 454 cats were selected, of which 30.2% [95% CI = 26.0% - 34.3%] were FIV-positive, 1.1% [95% CI = 0.9% - 1.2%] were FeLV-positive, and 0.7% [95% CI = 0.1% - 1.3%] were coinfected by both retroviruses. No statistical association was found between the studied retroviruses (P = 0.144). Multivariable analysis detected significant associations between FIV infection and male sex [OR = 5.7, 95% CI = 3.0-10.7, P < 0.0001), age between 19 and 78 months [OR = 5.2, 95% CI = 2.2-12.1, P < 0.0001], age greater than 78 months [OR = 12.8, 95% CI = 5.1-31.9, P < 0.0001], crossbreed [OR = 4.1, 95% CI = 1.2-13.4, P = 0.021], the presence of oral disease [OR = 2.1, 95% CI = 1.3-3.4, P = 0.004], reduced red blood cell (RBC) count [OR = 3.7, 95% CI = 1.9-7.2, P < 0.0001], and an albumin:globulin (A:G) ratio lower than 0.6 [OR = 3.4, 95% CI = 1.6-7.1, P = 0.001]. No statistical analyses were performed for FeLV infection due to the low number of positive animals. In the quantitative analyses of hematological parameters, FIV-positive cats presented lower values for RBC, hemoglobin, hematocrit, lymphocytes, and platelets compared to the negative animals. In the biochemical profile, cats infected with FIV showed higher creatinine, urea, total protein, and globulin values, while lower values for albumin and A:G ratio were observed (P < 0.05). The findings of this study characterized the prevalence, clinicopathological findings, and risk factors associated with FIV and FeLV in cats from the Brazilian semiarid region. They may help support veterinary practitioners in diagnosing feline retroviruses. The FIV prevalence observed is among the highest reported in Brazil, demonstrating the need for prevention and control strategies for this retrovirus., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Autologous platelet-rich plasma (PRP) contains growth factors (GFs) that modulate the expression of inflammatory cells; thus, these products could be considered a good strategy to favor tissue regeneration in feline immunodeficiency (FIV) positive cats. However, there is no scientific documentation on obtaining PRP in FIV-positive cats. Authors hypothesized that PRP can be obtained in FIV cats following the PRGF®-Endoret® methodology. The objectives of this study were to compare the platelet, erythrocyte, and leukocyte concentration between whole blood (WB) and the PRP; and determine the concentration of platelet-derived growth factor BB (PDGF-BB) and transforming growth factor β1 (TGF-β1) in FIV-positive cats. Sixteen adults FIV-positive asymptomatic cats were included in the study. WB samples were drawn and the PRP was obtained by centrifugation at 265g for 10 min. Erythrocyte and leukocyte, platelets, and mean platelet volume (MPV) were determined both in WB and in PRP. PDGF-BB and TGF-β1 concentrations were additionally determined in PRP. Platelet concentration increased 1.1 times in PRP fraction compared to WB, but no significant differences were reported. MPV was statistically higher in WB than in PRP (p = 0.001). Erythrocytes and leukocytes counts were decreased by 99% and 92%, respectively in the PRP fraction (p < 0.001). Regarding TGF-ß1, a higher concentration was shown in the PRP (p < 0.02). Although the product obtained could not be classified as PRP according to the PRGF®-Endoret® methodology, based on the drastic reduction of RBC and WBC, the PLT concentrate is of high purity., Competing Interests: Declaration of competing interest The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

The zoonotic virus SARS-CoV-2, which causes severe acute respiratory syndrome in humans (COVID-19), has been identified in cats. Notably, most positive cases were in cats that had close contact with infected humans, suggesting a role for humans in animal transmission routes. Previous studies have suggested that animals with immune depletion are more susceptible to SARS-CoV-2 infection. To date, there is limited evidence of SARS-CoV-2 infections in stray and free-range cats affected by other pathogens. In this study, we investigated infections caused by SARS-CoV-2, Leishmania spp., Toxoplasma gondii, Mycoplasma spp., Bartonella spp., Feline leukemia virus (FeLV), and Feline immunodeficiency virus (FIV) in stray cats from an urban park in Brazil during the COVID-19 pandemic. From February to September 2021, 78 mixed-breed cats were tested for SARS-CoV-2 and hemopathogens using molecular analysis at Américo Renné Giannetti Municipal Park, Belo Horizonte, Minas Gerais, Brazil. An enzyme-linked immunosorbent assay (ELISA) was used to detect IgG in T. gondii. None of the animals in this study showed any clinical signs of infections. The SARS-CoV-2 virus RNA was detected in 7.7 % of cats, and a whole virus genome sequence analysis revealed the SARS-CoV-2 Delta lineage (B.1.617.2). Phylogenetic analysis showed that SARS-CoV-2 isolated from cats was grouped into the sublineage AY.99.2, which matches the epidemiological scenario of COVID-19 in the urban area of our study. Leishmania infantum was detected and sequenced in 9 % of cats. The seroprevalence of T. gondii was 23.1 %. Hemotropic Mycoplasma spp. was detected in 7.7 % of the cats, with Mycoplasma haemofelis and Candidatus Mycoplasma haemominutum being the most common. Bartonella henselae and Bartonella clarridgeiae were detected in 38.5 % of the cats, FeLV was detected in 17,9 %, and none of the cats studied tested positive for FIV. This study reports, for the first time, the SARS-CoV-2 infection with whole-genome sequencing in stray cats in southeastern Brazil and co-infection with other pathogens, including Bartonella spp. and Feline leukemia virus. Our study observed no correlation between SARS-CoV-2 and the other detected pathogens. Our results emphasize the importance of monitoring SARS-CoV-2 in stray cats to characterize their epidemiological role in SARS-CoV-2 infection and reinforce the importance of zoonotic disease surveillance., Competing Interests: Declaration of Competing Interest The authors declare no conflict of interest., (Copyright © 2023. Published by Elsevier B.V.)

Feline leishmanial infection is reported worldwide, but the epidemiological role of domestic cats in the leishmaniasis cycle remains unclear, and cats might act as cryptic reservoir hosts in endemic areas with no feline leishmaniosis cases. Considering that, a serological screening for anti-Leishmania spp. antibodies was performed by indirect immunofluorescence antibody test (IFAT) in 389 necropsied cats' serum samples from a new visceral leishmaniasis transmission area with no feline leishmanial infection reported to unveil if the cats are being exposed to the parasite. The overall seroprevalence for Leishmania spp. was 11.05% (43/389). No association was found between sex, neutering status, age group, breed, coat length, feline immunodeficiency virus (FIV) infection, and Leishmania spp. antibody detection. A positive association was found with coat color (cats within the orange spectrum with white [particolor]) (OR = 2.47, CI 95% 1 - 6.13, P = 0.044) and a negative association (OR = 0.38, CI 95% 0.18 - 0.79, P = 0.01) between feline leukemia virus (FeLV) infection and IFAT positivity for Leishmania spp. Therefore, it is concluded that the seroprevalence found was greater than 10%, indicating contact of the protozoan with cats in the region served., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) are retroviral infections of cats worldwide whose clinical manifestations range from mild to severe disease. In both cases, infected cats can live a long life with proper care and should be managed to prevent infection of other cats. Dirofilaria immitis , the nematode that causes heartworm disease, can infect cats in any region where dogs are infected. Though cats are more resistant to infection, clinical diseases in the form of heartworm-associated respiratory disease can cause death. Screening for these infectious diseases enables veterinarians to manage their cases and prevent the spread to other cats. We describe the diagnostic accuracy of a point-of-care immunoassay for FIV, FeLV, and heartworm, compared to reference methods commonly available through reference laboratories to the practicing veterinarian. For FIV, we report 100% sensitivity (95% confidence limits (CL): 96.2-100%) and 97.8% specificity (95% CL: 95.4-99.4%). For FeLV, we report 100% sensitivity (95% CL: 97.7-100%) and 99.2% specificity (95% CL: 97.1-99.9%). And for heartworm, we report 90.2% sensitivity (95% CL: 76.9-97.3%) and 100% specificity (95% CL: 98.3-100%). Veterinarians may expect this performance relative to the reference methods they use for confirmatory serological testing.

This study performed a serological assay to assess the exposure of free-ranging cougars ( Puma concolor ) to four selected infectious agents, including Toxoplasma gondii , Leptospira spp., the feline immunodeficiency virus (FIV), and the feline leukemia virus (FeLV). Serum samples were collected from 27 free-ranging cougars along the Tietê River Basin, in the central region of the State of São Paulo, Brazil. The presence of antibodies against T. gondii was detected in 59.3% (16/27) of the serum samples through the modified agglutination test (MAT-t), which was the most prevalent agent. The microscopic agglutination technique (MAT-1) was used to investigate the occurrence of anti- Leptospira spp. antibodies, showing that 11.1% (3/27) of the sampled cougars were seropositive. The only serovar detected was Djasiman ( L. interrogans ). A commercial enzyme-linked immunosorbent assay (ELISA) licensed for use in domestic felines was used to investigate the occurrence of retroviruses. The ELISA test kits detected a prevalence of 11.1% (3/27) of FIV antibodies, while none of the samples tested showed any evidence of FeLV antigen. These results suggest that free-ranging cougars are exposed to potentially pathogenic agents. This study presented the first recorded occurrence of the serovar Djasiman in P. concolor .

Feline immunodeficiency virus (FIV) is a lentivirus in the family Retroviridae that infects domestic cats resulting in an immunodeficiency disease featuring a progressive and profound decline in multiple sets of peripheral lymphocytes. Despite compelling evidence of FIV-associated immunopathology, there are conflicting data concerning the clinical effects of FIV infection on host morbidity and mortality. To explore FIV-associated immunopathogenesis and clinical disease, we experimentally inoculated a cohort of four specific pathogen-free kittens with a biological isolate of FIV clade C and continuously monitored these animals along with two uninfected control animals for more than thirteen years from the time of inoculation to the humane euthanasia endpoint. Here, we report the results obtained during the late asymptomatic and terminal phases of FIV infection in this group of experimentally FIV-infected cats.

Stray cats can host (zoonotic) viral pathogens and act as a source of infection for domestic cats or humans. In this cross-sectional (sero)prevalence study, sera from 580 stray cats living in 56 different cat groups in rural areas in The Netherlands were collected from October 2020 to July 2022. These were used to investigate the prevalence of the cat-specific feline leukemia virus (FeLV, n = 580), the seroprevalence of the cat-specific feline viruses feline immunodeficiency virus (FIV, n = 580) and feline coronavirus (FCoV, n = 407), and the zoonotic virus severe acute respiratory coronavirus-2 (SARS-CoV-2, n = 407) using enzyme-linked immunosorbent assays (ELISAs). ELISA-positive results were confirmed using Western blot (FIV) or pseudovirus neutralization test (SARS-CoV-2). The FIV seroprevalence was 5.0% (95% CI (Confidence Interval) 3.4-7.1) and ranged from 0-19.0% among groups. FIV-specific antibodies were more often detected in male cats, cats ≥ 3 years and cats with reported health problems. No FeLV-positive cats were found (95% CI 0.0-0.6). The FCoV seroprevalence was 33.7% (95% CI 29.1-38.5) and ranged from 4.7-85.7% among groups. FCoV-specific antibodies were more often detected in cats ≥ 3 years, cats with reported health problems and cats living in industrial areas or countryside residences compared to cats living at holiday parks or campsites. SARS-CoV-2 antibodies against the subunit 1 (S1) and receptor binding domain (RBD) protein were detected in 2.7% (95% CI 1.4-4.8) of stray cats, but sera were negative in the pseudovirus neutralization test and therefore were considered SARS-CoV-2 suspected. Our findings suggest that rural stray cats in The Netherlands can be a source of FIV and FCoV, indicating a potential risk for transmission to other cats, while the risk for FeLV is low. However, suspected SARS-CoV-2 infections in these cats were uncommon. We found no evidence of SARS-CoV-2 cat-to-cat spread in the studied stray cat groups and consider the likelihood of spillover to humans as low.

A high frequency of feline leishmaniasis has been reported in several countries. However, much information about disease progression in cats still needs to be clarified. This study aimed to verify the occurrence of clinicopathological changes in cats infected with Leishmania infantum. A total of 60 cats were divided into three groups of 20 animals each: control, suspects, and infected. All 60 cats underwent blood count and biochemical analyses. Serum samples from 20 animals with leishmaniasis were also used to diagnose feline immunodeficiency virus and feline leukemia virus. A total of five of the infected animals underwent necropsy for a histopathological study. The main clinical findings in cats with leishmaniasis were lymphadenomegaly (65%), alopecia (55%), ulcerative skin lesions and weight loss (40%), skin nodules (25%), a significant reduction in red blood cells (p=0.0005) and hematocrit (p=0.0007), hyperplasia in spleen 4/5(80%), presence of Leishmania in the spleen 2/5(40%), hepatitis 3/5(60%), liver degeneration 4/5(80%) and inflammatory nephropathy 3/5(60%). It was concluded that cats with leishmaniasis presented significant clinical, hematological, and histopathological alterations compatible with L. infantum infection. The observation of lymphadenomegaly, weight loss, skin lesions and low concentration of red blood cells, contributes significantly to the diagnosis and analysis of progression of feline leishmaniasis.

Enzyme-linked immunosorbent assay (ELISA) for viral antigen is commonly used for the diagnosis of progressive feline leukemia virus (FeLV) infection but is not able to determine the true prevalence of infection when used as the sole test. Additional testing to detect proviral DNA will identify regressive (antigen negative) FeLV infections as well as progressive infections. Therefore, this study aimed to determine the prevalence of progressive and regressive FeLV infection, outcome-associated factors, and hematologic changes. A cross-sectional study was performed on 384 cats selected from routine hospital care. Blood samples were subjected to complete blood count, ELISA for FeLV antigen and FIV antibody, and nested PCR amplifying the U3- LTR region and gag gene, which are conserved in most exogenous FeLV. The prevalence of FeLV infection was 45.6% (CI 95% 40.6-50.6%). The prevalence of progressive infection (FeLV + P) was 34.4% (CI 95% 29.6-39.1%), that of regressive infection (FeLV+R) was 10.4% (CI 95% 7.4-13.4%), for discordant but positive results 0.8% (CI 95% 0.75-0.84%), for FeLV + P coinfected with FIV 2.6% (CI 95% 1.2-4.0%), and FeLV + R coinfected with FIV 1.5% (CI 95% 0.3-2.7%). Male cats were three times more likely to be in the FeLV + P group. Cats coinfected with FIV were 4.8 times more likely to belong to the FeLV + R group. In the FeLV + P group, the main clinical changes were lymphoma (38.5%), anemia (24.4%), leukemia (17.9%), concomitant infections (15.4%), and feline chronic gingivostomatitis - FCGS (3.8%). In the FeLV + R group, the main clinical signs were anemia (45.4%), leukemia (18.2%), concomitant infections (18.2%), lymphoma (9.1%), and FCGS (9.1%). Cats in the FeLV + P and FeLV + R groups showed mainly thrombocytopenia (56.6% and 38.2%), non-regenerative anemia (32.8% and 23.5%), and lymphopenia (33.6% and 20.6%). Hemoglobin concentration, packed cell volume (PCV), platelet count, lymphocytes, and eosinophils in the FeLV + P and FeLV + R groups had lower medians than the control group (FeLV/FIV-uninfected, healthy). Erythrocyte and eosinophil counts were statistically different among the three groups, with the medians of the FeLV + P and FeLV + R groups being lower than those of the control group. In addition, the median PCV and band neutrophil counts were higher in FeLV + P than in FeLV + R. Our results show a high prevalence of FeLV, different factors associated with the course of infection, and more frequent and severe hematologic changes in progressive infections compared with regressive infections., Competing Interests: Declaration of Competing Interest None., (Copyright © 2023. Published by Elsevier B.V.)

One hundred and sixty-six cats from two animal shelters were subjected to enzyme-linked immunosorbent assay (ELISA), indirect immunofluorescence antibody test (IFAT), conventional polymerase chain reaction (cPCR), quantitative PCR (qPCR) and parasitological tests (PA) for the diagnosis of Leishmania spp. Among them, 15% (25/166), 53.6% (89/166), 3.6% (06/166) and 1.8% (03/166) were positive by ELISA, IFAT, both PCRs and PA, respectively. The sequencing of ITS-1 PCR amplicons revealed a 100% match with Leishmania infantum. After the Leishmania spp. survey, 12 cats were selected and divided into two groups for clinical, hematological, and biochemical analysis: six L. infantum positive cats (G1) and six Leishmania spp. negative cats (G2). All the cats were negative for feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV). A statistical analysis indicated significantly low platelet counts and significant hyperproteinemia associated with hypoalbuminemia in positive cats (p<0.05). Our results suggest that in endemic areas, cats with clinical signs of feline leishmaniosis (such as skin lesions, weight loss and/or enlarged lymph nodes) and that exhibit hematological and biochemical changes, such as low platelet counts and hyperproteinemia with hypoalbuminemia, should be tested for Leishmania spp. infection.

Severe Acute Respiratory Syndrome Coronavirus 2 is the causative agent of Coronavirus Disease 2019 in humans. Among domestic animals, cats are more susceptible to SARS-CoV-2 than dogs. The detection of anti-SARS-CoV-2 antibodies in seemingly healthy cats and/or infected cats which are in close contact with infected humans has been described. The presence of animals that tested positive by serology or molecular techniques could represent a potential transmission pathway of SARS-CoV-2 that can spill over into urban wildlife. This study analyses the seroprevalence variation of SARS-CoV-2 in stray cats from different waves of outbreaks in a geographical area where previous seroepidemiological information of SARS-CoV-2 was available and investigate if SARS-CoV-2-seropositive cats were exposed to other co-infections causing an immunosuppressive status and/or a chronic disease that could lead to a SARS-CoV-2 susceptibility. For this purpose, a total of 254 stray cats from Zaragoza (Spain) were included. This analysis was carried out by the enzyme-linked immunosorbent assay using the receptor binding domain of Spike antigen and confirmed by serum virus neutralization assay. The presence of co-infections including Toxoplasma gondii, Leishmania infantum, Dirofilaria immitis, feline calicivirus, feline herpesvirus type 1, feline leukemia virus and feline immunodeficiency virus, was evaluated using different serological methods. A seropositivity of 1.57% was observed for SARS-CoV-2 including the presence of neutralizing antibodies in three cats. None of the seropositive to SARS-CoV-2 cats were positive to feline coronavirus, however, four SARS-CoV-2-seropositive cats were also seropositive to other pathogens such as L. infantum, D. immitis and FIV (n = 1), L. infantum and D. immitis (n = 1) and L. infantum alone (n = 1).Considering other pathogens, a seroprevalence of 16.54% was detected for L. infantum, 30.31% for D. immitis, 13.78%, for T. gondii, 83.86% for feline calicivirus, 42.52% for feline herpesvirus type 1, 3.15% for FeLV and 7.87% for FIV.Our findings suggest that the epidemiological role of stray cats in SARS-CoV-2 transmission is scarce, and there is no increase in seropositivity during the different waves of COVID-19 outbreaks in this group of animals. Further epidemiological surveillances are necessary to determine the risk that other animals might possess even though stray cats do not seem to play a role in transmission., (© 2022. The Author(s), under exclusive licence to Springer Nature B.V.)

The aim of this study was to detect molecularly vector borne pathogens (VBPs) in domiciled cats tested for Feline immunodeficiency virus (FIV) and Feline leukemia virus (FeLV). Blood samples (n = 119) were analyzed microscopically and molecularly through PCR and sequenced for the detection of the following pathogens: piroplasmids., Bartonella henselae, Cytauxzoon felis, Ehrlichia canis, Leishmania spp., hemotropic Mycoplasma spp., Trypanosoma spp., and Ricketssia spp. Animals were also serological assessed for detection of antibodies against FIV and FeLV. Out of all animals, 20.16% (24/119) tested positive for at least one VBPs at molecular examination. Conversely, no animal resulted positive at microscopic analysis. The most prevalent pathogen was hemotropic Mycoplasma haemofelis (8.40%; 10/119), followed by Candidatus Mycoplasma haemominutum (5.88%; 7/119), E. canis (5.04%; 6/119), C. felis (0.84%; 1/119) and B. henselae (0.84%; 1/119). One animal (0.84%; 1/119) was co-infected with. E. canis and B. henselae. A total of 5.88% (7/119) and 1.68% (2/119) tested positive for FIV and FeLV, respectively. Data of this study demonstrate that owned cats can be at risk of hemotropic Mycoplasma spp., E. canis, C. felis and B. henselae. Therefore, preventive measures against vectors of these pathogens should be implemented in order to reduce the risk of exposition and consequently infection. Additionally, aggressive behaviors among cats should be avoided, especially because hemotropic Mycoplasma spp. may be transmitted through the bite of animals., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV) are retroviruses affecting cats worldwide, and the prevalence of infection varies considerably according to the geographic area. We retrospectively described FIV- and FeLV-associated diseases in a population of 1470 necropsied cats, of which 396 (26.9%) were infected with FeLV, 199 (13.5%) with FIV, and 134 (9.1%) with FeLV and FIV concomitantly. Cats infected with FeLV (OR 3.4) and co-infected with FeLV and FIV (OR 1.9) were more likely to have neoplasms. The diagnosis of lymphoma and leukemia was higher in cats infected with FeLV (OR 3.9 and 19.4, respectively) and coinfected with FeLV and FIV (OR 1.9 and 19.3, respectively). The odds of diagnosing bacterial diseases were higher in cats coinfected with FeLV and FIV (OR: 2.8), whereas the odds of viral diseases were higher in those infected with FeLV (OR: 2.8), with 2.2 times more diagnoses of feline infectious peritonitis. Neoplastic and infectious diseases in FIV-infected cats did not differ significantly from those in uninfected cats. According to our results, a high prevalence of retroviral infections was observed in southern Brazil, mainly in relation to FeLV. Infected cats were significantly younger than uninfected cats. The main causes of death associated with FeLV infection and FeLV and FIV coinfection were neoplastic and infectious diseases. In contrast, FIV infection was not associated with any specific condition., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Tsushima leopard cats (TLC; Prionailurus bengalensis euptilurus ) only inhabit Tsushima Island, Nagasaki, Japan and are critically endangered and threatened by infectious diseases. The feline foamy virus (FFV) is widely endemic in domestic cats. Therefore, its transmission from domestic cats to TLCs may threaten the TLC population. Thus, this study aimed to assess the possibility that domestic cats could transmit FFV to TLCs. Eighty-nine TLC samples were screened, and FFV was identified in seven (7.86%). To assess the FFV infection status of domestic cats, 199 domestic cats were screened; 14.07% were infected. The phylogenetic analysis revealed that the FFV partial sequence from domestic cats and TLC sequences clustered in one clade, suggesting that the two populations share the same strain. The statistical data minimally supported the association between increased infection rate and sex ( p = 0.28), indicating that FFV transmission is not sex dependent. In domestic cats, a significant difference was observed in FFV detection in feline immunodeficiency virus ( p = 0.002) and gammaherpesvirus1 infection statuses ( p = 0.0001) but not in feline leukemia virus infection status ( p = 0.21). Monitoring FFV infection in domestic cats and TLC populations is highly recommended as part of TLC surveillance and management strategies.

A cross-sectional study was conducted on 274 cats in Southern Brazil to estimate the prevalence of Mycoplasma haemofelis PCR, associated factors, and its correlation with ELISA for FeLV and FIV. The apparent prevalence of M. haemofelis was 6.6% (18/274) (95% CI: 3.6-9.5%), of which 33.3% (6/18) had co-infection with FeLV, 5.6% (1/18) with FIV, and 5.6% (1/18) with both. Male cats were more likely to be positive for M. haemofelis [OR: 7.07 (1.97-25.34)]. Only three M. haemofelis-positive cats showed related clinical changes, such as mucosal pallor. A statistically significant difference was observed between M. haemofelis-positive cats and the negative control group for age, hemoglobin concentration, packed cell volume, and rod neutrophil counts. Mycoplasma haemofelis is prevalent in southern Brazil, with a higher risk in male cats. Most cats could be classified as asymptomatic carriers since they were healthy., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier Ltd.)

A cross-sectional study was carried out between April 2020 and August 2021. Blood samples were collected from 260 household cats recruited in different clinics in North and Mount Lebanon, with the aim of determining the seroprevalence of feline immunodeficiency virus (FIV) and feline leukaemia virus (FeLV). The seroprevalence reported reached 18.84% (95% CI 0.14-0.24) and 13.84% (95% CI 0.09-0.18) for FIV and FeLV, respectively. FIV seropositivity was associated with a younger age, health and neuter status, lymphoma, lethargy, and vomiting. Furthermore, male sex, neuter status, lymphoma, anaemia, lethargy, and vomiting were significantly associated with FeLV seropositivity. This first data from Lebanon emphasizes the need for implementing preventive programmes to cope with FIV- and FeLV-associated morbidity and mortality among cats., Competing Interests: Declarations of interest None., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Testing platforms that leverage automation, require minimal sample volume, and enable various tests to be performed simultaneously on a single sample have the potential to improve workflow and efficiency in veterinary diagnostic laboratories. We evaluated a barcoded magnetic bead (BMB) technology using established immunoassays for detection of feline leukemia virus (FeLV) p27 antigen and antibody against feline immunodeficiency virus (FIV). Analytical sensitivity, limit of blank, and limit of detection were used to establish a functional sensitivity of 1.00 ng/mL of inactivated FeLV antigen and 35.7 ng/mL of anti-FIV monoclonal antibody. Common interferents, such as hemoglobin, lipid, and bilirubin, were not found to interfere with the performance of the assay. Intra- and inter-assay CVs were <13% for both assays using manufactured samples. Using a set of 116 feline samples, the diagnostic accuracy of our multiplex assay was 100% compared to reference assays. Performance in a convenience set of 1,000 feline samples submitted to a commercial diagnostic laboratory revealed a proportion of positive results of 1.3% for FeLV and 3.7% for FIV. BMB technology should enable rapid screening of samples for various markers in a single immunoassay well.

Client-owned cats who underwent a post-mortem examination (n = 3,108) at a veterinary medical teaching hospital between 1989 and 2019 were studied to determine longevity and factors affecting mortality. Demographic factors, environmental factors, age, and causes of death were assessed. Sexes included 5.66% intact females, 39.86% spayed females, 6.95% intact males and 47.49% neutered males. 84.2% were mixed breed cats. Age at death was known for 2,974 cases with a median of 9.07 years. Cancer was the most common pathophysiologic cause of death (35.81%) and was identified in 41.3% of cats. When categorized by organ system, mortality was most attributed to multiorgan/systemic (21.72%). Renal histologic abnormalities were noted in 62.84% of cats but was considered the primary cause of death in only 13.06% of cats. Intact female and male cats had significantly shorter lifespans than their spayed or neutered counterparts. FeLV positive status was associated with decreased longevity (P<0.0001) while FIV status was not. This study reports on risk factors associated with mortality and highlights areas of research that may contribute to improved lifespan in cats., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2022 Kent et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Cats are susceptible to coronavirus infections, including infection by human severe acute respiratory syndrome coronavirus (SARS-CoV). In human ABO system blood groups, alloantibodies can play a direct role in resistance to infectious diseases. Individuals with the AB blood type were over-represented in the SARS-CoV-2 infection group. Blood type AB individuals lack both anti-A and anti-B antibodies, and therefore lack the protective effect against SARS-CoV-2 infection given by these antibodies. Starting from this knowledge, this pilot preliminary study evaluated a possible association between feline blood phenotypes A, B, and AB and serostatus for SARS-CoV-2 antibodies in cats. We also investigated selected risk or protective factors associated with seropositivity for this coronavirus. A feline population of 215 cats was analysed for AB group system blood phenotypes and antibodies against the nucleocapsid (N-protein) SARS-CoV-2 antigen using a double antigen ELISA. SARS-CoV-2 seropositive samples were confirmed using a surrogate virus neutralization test (sVNT). Origin (stray colony/shelter/owned cat), breed (DSH/non DSH), gender (male/female), reproductive status (neutered/intact), age class (kitten/young adult/mature adult/senior), retroviruses status (seropositive/seronegative), and blood phenotype (A, B, and AB) were evaluated as protective or risk factors for SARS-CoV-2 seropositivity. Seropositivity for antibodies against the SARS-CoV-2 N-protein was recorded in eight cats, but only four of these tested positive with sVNT. Of these four SARS-CoV-2 seropositive cats, three were blood phenotype A and one was phenotype AB. Young adult age (1-6 years), FeLV seropositivity and blood type AB were significantly associated with SARS-CoV-2 seropositivity according to a univariate analysis, but only blood type AB ( p = 0.0344, OR = 15.4, 95%CI: 1.22-194.39) and FeLV seropositivity ( p = 0.0444, OR = 13.2, 95%CI: 1.06-163.63) were significant associated risk factors according to a logistic regression. Blood phenotype AB might be associated with seropositivity for SARS-CoV-2 antibodies. This could be due, as in people, to the protective effect of naturally occurring alloantibodies to blood type antigens which are lacking in type AB cats. The results of this pilot study should be considered very preliminary, and we suggest the need for further research to assess this potential relationship.

Feline immunodeficiency virus (FIV) infection in experimentally infected domestic cats produces characteristic clinical manifestations including hematological changes, neurological disease, neoplasia (most notably lymphoma) and lymphopenia-mediated immunodeficiency predisposing cats to a range of secondary infections. Conflicting reports exist, however, with regard to disease associations and survival time in naturally FIV-infected cats. The purpose of this retrospective case−control study was to investigate the effect of natural FIV infection on hematological, blood biochemical and urinalysis parameters and survival time in three cohorts of pet cats in Australia. Cohorts 1 and 2 were recruited from a large veterinary hospital in Melbourne, Victoria (n = 525 and 282), while a third cohort consisted of cats recruited from around Australia as part of a FIV field vaccine efficacy trial (n = 425). FIV-infected cats in cohorts 1, 2 and 3 were found to have 15/37 (41%), 13/39 (33%) and 2/13 (15%) clinicopathological parameters significantly different to FIV-uninfected cats, respectively. Two changes in FIV-infected cats in cohort 1, hypochromia (low hemoglobin) and hyperglobulinemia, were outside the supplied reference intervals and should serve as diagnostic triggers for FIV testing. Kaplan−Meier survival analysis of cats in cohorts 1 and 2 combined did not find any difference between FIV-infected and FIV-uninfected cats, however a confounding factor was a large euthanasia rate within the first 12 months in both groups. Three significant (p < 0.05) spatial clusters of FIV infection were identified in Melbourne. A possible relationship between FIV infection status and socioeconomic disadvantage was discovered, based on three government indices of socioeconomic status (p < 0.001). Until longitudinal field studies are performed in Australia to further investigate the long-term effects of natural FIV infection, Australian veterinarians should consider FIV to be an important infection of pet cats, and recommend measures to prevent FIV infection.

Our study investigated the prevalence of feline herpesvirus-1 (FHV-1), feline calicivirus (FCV), feline immunodeficiency virus (FIV), and feline leukemia virus (FeLV) in captive Siberian tigers in Northeastern China. A total of 324 blood samples and 33 nasopharyngeal swab samples of Siberian tigers collected from 2019 to 2021 in three cities were investigated by nested PCR. The results showed that 28.1% (91/324) tigers were infected with at least one virus; the positive rates of FHV-1, FCV, and FIV were 17.3%, 13.6%, and 0.9%, respectively; and the coinfection prevalence was 13.2%. No FeLV-positive sample was detected. And we found that the blood is the best for FCV, FIV, and FeLV detection, but nasopharyngeal swabs for FHV-1. By comparing the gD genes, TK gene, and gI gene of FHV-1, the homology of the three FHV-1 positive strains in this study was found to be 91.5%-99.9% shared with tigers and domestic cats. Based on a comparison of the nucleic acid sequences of 13 FCV strains, we found that the homology of strain HB-1926 with the other strains in this study was only about 77.7%, but shared 99.3% and 98.6% homology with Urnaba strain in American cat and TG1 strain in Chinese tiger, respectively. However, the other 12 FCV strains shared 87.1%-87.5% homology compared with the Chinese domestic cats. Phylogenetic tree analysis showed that the HB-1926 strain was not in the same clade as other strains. The fragments gag-p26, pol-RT, and pol-RNAse of Siberian tiger FIV shared more than 99% homology than domestic cats FIV subtype A. This study demonstrated that captive Siberian tigers in Northeastern China were exposed to FHV-1, FCV, and FIV, and it is necessary to develop more effective vaccines and improve daily management measures., (© 2022 Wiley-VCH GmbH.)

We disclose a series of potent anti-viral 1,2,3-dithiazoles, accessed through a succinct synthetic approach from 4,5-dichloro-1,2,3-dithiazolium chloride (Appel's salt). A series of small libraries of compounds were screened against feline immunodeficiency virus (FIV) infected cells as a model for HIV. This approach highlighted new structure activity relationship understanding and led to the development of sub-micro molar anti-viral compounds with reduced toxicity. In addition, insight into the mechanistic progress of this system is provided via advanced QM-MM modelling. The 1,2,3-dithiazole represents a versatile scaffold with potential for further development to treat both FIV and HIV., (Copyright © 2022 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

The feline immunodeficiency virus (FIV) is a widespread lentivirus of felids. Due to its worldwide diffusion and the lack of an effective preventive and therapeutic protocol, it has a high impact on the cats' health. Several therapeutical protocols have been proposed, among those, phytotherapeutic compounds have been tested with the purpose to find a possible natural treatment. The most studied active compounds are derived from Ganoderma lucidum, Cordyceps sinensis, and Trametes versicolor . The present study aims to investigate in vitro antiviral effects of a commercially available compound HELP-TH1 (Camon, S.p.A., Italy) against FIV. The antiviral effect of HELP-TH1 was evaluated by quantifying and comparing the viral load of control groups, infected and not-treated cells, vs both experimental groups, infected and treated cells. Our data indicate that HELP-TH1 reduce the viral load in the experimental conditions demonstrating its antiviral effect.

Despite the passage of over 30 years since its discovery, the importance of feline immunodeficiency virus (FIV) on the health and longevity of infected domestic cats is hotly debated amongst feline experts. Notwithstanding the absence of good quality information, Australian and New Zealand (NZ) veterinarians should aim to minimise the exposure of cats to FIV. The most reliable way to achieve this goal is to recommend that all pet cats are kept exclusively indoors, or with secure outdoor access (e.g., cat enclosures, secure gardens), with FIV testing of any in-contact cats. All animal holding facilities should aim to individually house adult cats to limit the spread of FIV infection in groups of animals that are stressed and do not have established social hierarchies. Point-of-care (PoC) FIV antibody tests are available in Australia and NZ that can distinguish FIV-infected and uninfected FIV-vaccinated cats (Witness™ and Anigen Rapid™). Although testing of whole blood, serum or plasma remains the gold standard for FIV diagnosis, PoC testing using saliva may offer a welfare-friendly alternative in the future. PCR testing to detect FIV infection is not recommended as a screening procedure since a negative PCR result does not rule out FIV infection and is only recommended in specific scenarios. Australia and NZ are two of three countries where a dual subtype FIV vaccine (Fel-O-Vax® FIV) is available and offers a further avenue for disease prevention. Since FIV vaccination only has a reported field effectiveness of 56% in Australia, and possibly lower in NZ, FIV-vaccinated cats should undergo annual FIV testing prior to annual FIV re-vaccination using a suitable PoC kit to check infection has not occurred in the preceding year. With FIV-infected cats, clinicians should strive to be even more thorough than usual at detecting early signs of disease. The most effective way to enhance the quality of life and life expectancy of FIV-infected cats is to optimise basic husbandry and to treat any concurrent conditions early in the disease course. Currently, no available drugs are registered for the treatment of FIV infection. Critically, the euthanasia of healthy FIV-infected cats, and sick FIV-infected cats without appropriate clinical investigations, should not occur., (© 2022 Boehringer Ingelheim Animal Health Australia Pty Ltd. Australian Veterinary Journal published by John Wiley & Sons Australia, Ltd on behalf of Australian Veterinary Association.)

Objectives: The relationship between blood group antigens and disease has been studied in humans. Blood types have been associated with both decreased and increased rates of various infections. In addition, blood group expression has been shown to vary with some cancers and gastrointestinal diseases. The objective of this study was to explore whether there is a relationship between blood type and retroviral infections in cats., Methods: Case records from a veterinary research laboratory, veterinary teaching hospitals and veterinary blood banks were retrospectively searched for cats where both blood type and retroviral status (feline leukemia [FeLV], feline immunodeficiency virus [FIV] or both) were listed (part 1). In addition, a sample of 33 cats with confirmed FIV infection was genotyped to determine blood groups (part 2)., Results: In part 1, 709 cats were identified, 119 of which were positive for retroviral infection. Among all cases, 621 were type A (87.6%), 68 were type B (9.6%) and 20 were type AB (2.8%). There was no relationship between overall retroviral status (positive/negative) and blood type ( P  = 0.43), between FeLV status and blood type ( P  = 0.86) or between FIV status and blood type ( P  = 0.94). There was no difference in the distribution of blood types between cats that were healthy and typed as possible blood donors vs sick cats that were typed prior to a possible transfusion ( P  = 0.13). In part 2, of the 33 FIV-infected cats, all blood group genotypes were identified, although this test did not discriminate type A from type AB., Conclusions and Relevance: No relationship was identified between feline retroviral status and blood type in this study. The relationship between blood type and other disease states requires further study in veterinary patients.

We evaluated the epidemiological, hematological, and pathological data of Leishmania spp., Toxoplasma gondii, Platynosomum illiciens, feline immunodeficiency virus (FIV), and feline leukemia virus (FeLV) infections and the coinfections in stray cats of an endemic area for leishmaniasis. The diagnosis was performed by serological tests and necropsy. We described gross lesions and histopathological findings. We used immunohistochemistry and chromogenic in situ hybridization for L. infantum detection. We found infection in 27 out of 50 sampled cats, among them, 14 presented coinfections. A strong correlation between splenomegaly and lymphadenomegaly with FeLV, and an association between hepatic lesions and cachexia with parasitism due to P. illiciens were observed. Moreover, we found a significant increase in the monocyte count in the FeLV-infected and a decrease in the red blood cell count in the FIV-infected animals. Amastigote forms of Leishmania spp. and tissue changes were detected in lymphoid organs of an animal coinfected with P. illiciens, T. gondii, and FIV. Polyparasitism recorded in stray cats of the Brazilian Midwest should be considered in effective control strategies for public health diseases. Moreover, stray cats of Campo Grande may be a source of infection of FIV, FeLV and P. illiciens for populations of domiciled cats.

Background: Age-related dementia has been documented in domestic cats; however, its interaction with naturally occurring feline immunodeficiency virus (FIV) infection has been investigated minimally., Methods: Visuospatial working memory (VSWM) and problem-solving (PS) ability were evaluated in FIV-infected (n = 37) and control cats (n = 39) using two cognitive tasks tested serially, which assessed the ability of cats to remember the location of a baited container after a set delay, then evaluated the capability of the cats to manipulate the container to obtain the food within a time limit. Cats were categorized using 7 years of age as a cut-off to determine age-related differences. The relationship between cognitive performance and FIV viral load was investigated using real-time PCR cycle threshold (C t ) values., Results: Age significantly affected VSWM and PS ability. Younger cats had better VSWM performance and PS ability compared to older cats with the same FIV status. There was no difference between younger FIV-positive and negative cats in either part of the task. While older FIV-positive cats had significantly worse VSWM than older FIV-negative cats, no differences were found in PS ability. Additionally, C t values predicted VSWM but not PS ability., Conclusion: Age-related cognitive impairments and FIV infection appear synergetic, causing greater cognitive deficits in older FIV-infected cats., (© 2022 The Authors. Veterinary Record published by John Wiley & Sons Ltd on behalf of British Veterinary Association.)

This retrospective study provides an analysis of the prevalence and detectability of canine distemper virus (CDV), feline leukemia virus (FeLV), and feline immunodeficiency virus (FIV) in ocelots (Leopardus pardalis) sheltered in a wild animal recovery center in Guayaquil, Ecuador. Blood samples of 19 rescued ocelots from 2019-20 were analyzed using FeLV p27 antigen enzyme-linked immunosorbent assays (ELISA) and commercial insulated isothermal reverse transcriptase PCR (iiRT-PCR) kits. Using this PCR we detected positive results for CDV (4/ 17; 23.5%) and FeLV (14/16; 87.5%), but not for FIV (0/8). Three previously positive cases of CDV and two of FeLV showed negative results on retesting 6 mo later. Moreover, a third analysis was conducted and was negative for CDV. Our results suggest that ocelots can recover from the local CDV and FeLV strains. An ELISA for the FeLV p27 antigen showed no capability to detect FeLV in ocelots that were confirmed positive by iiRT-PCR. Regional lineages, viral virulence, and host immune response capabilities should be addressed in further research to inform management and decision making for wildlife conservation., (© Wildlife Disease Association 2022.)

Background: Feline leishmaniosis caused by Leishmania infantum is often associated with feline immunodeficiency virus (FIV) infection; however, the role and clinical significance of this coinfection remain unknown. This study aimed to assess whether FIV is associated with L. infantum infection in cats from canine leishmaniosis endemic areas and to report the clinical signs and hematological alterations associated with coinfection., Methods: A retrospective matched case-control study (ratio 1:2) was conducted. Data of clinical examination and complete blood count (CBC) were selected from a cohort of 705 cats examined for epidemiological studies on feline leishmaniosis conducted between 2012 and 2019. Ninety-one FIV seropositive cases and 182 FIV seronegative control cats were selected. Matching was done according to age, sex, lifestyle and geographic provenience of case cats. Rapid ELISA devices were mainly used to detect anti-FIV antibodies. Anti-Leishmania IgG antibodies were detected by indirect-immunofluorescence test (IFAT). Leishmania DNA was searched in blood, oral and conjunctival swabs by quantitative real-time PCR., Results: Feline immunodeficiency virus seropositive cats had no hematological abnormalities suggestive of an advanced stage of FIV infection and were statistically more frequently IFAT positive, and their risk of being L. infantum antibody positive was 2.8 greater than in the FIV seronegatives. The association of FIV seropositivity with L. infantum antibody positivity was confirmed in the univariable model of logistic regression. A multivariate model found FIV infection and L. infantum PCR positivity as predictors of a positive L. infantum IFAT result. Male outdoor cats from rural or suburban areas were at risk for FIV and L. infantum antibody positivity. Clinical signs more frequently associated with the coinfection were oral lesions, pale mucous membranes and low body condition score (BCS)., Conclusions: This study documents that FIV seropositive cats with no hematological abnormalities suggestive of an advanced stage of FIV infection are more prone to be L. infantum seroreactive by IFAT in endemic areas. Therefore, FIV seropositive cats should be tested for L. infantum antibodies and treated for preventing sand fly bites. Pale mucous membranes, low BCS and oral lesions but no CBC abnormalities were significantly associated with the coinfection., (© 2022. The Author(s).)

A new coronavirus known as SARS-CoV-2 emerged in Wuhan in 2019 and spread rapidly to the rest of the world causing the pandemic disease named coronavirus disease of 2019 (COVID-19). Little information is known about the impact this virus can cause upon domestic and stray animals. The potential impact of SARS-CoV-2 has become of great interest in cats due to transmission among domestic cats and the severe phenotypes described recently in a domestic cat. In this context, there is a public health warning that needs to be investigated in relation with the epidemiological role of this virus in stray cats. Consequently, in order to know the impact of the possible transmission chain, blood samples were obtained from 114 stray cats in the city of Zaragoza (Spain) and tested for SARS-CoV-2 and other selected pathogens susceptible to immunosuppression including Toxoplasma gondii, Leishmania infantum, feline leukaemia virus (FeLV) and feline immunodeficiency virus (FIV) from January to October 2020. Four cats (3.51%), based on enzyme-linked immunosorbent assay (ELISA) using the receptor binding domain (RBD) of Spike antigen, were seroreactive to SARS-CoV-2. T. gondii, L. infantum, FeLV and FIV seroprevalence was 12.28%, 16.67%, 4.39% and 19.30%, respectively. Among seropositive cats to SARS-CoV-2, three cats were also seropositive to other pathogens including antibodies detected against T. gondii and FIV (n = 1); T. gondii (n = 1); and FIV and L. infantum (n = 1). The subjects giving positive for SARS-CoV-2 were captured in urban areas of the city in different months: January 2020 (2/4), February 2020 (1/4) and July 2020 (1/4). This study revealed, for the first time, the exposure of stray cats to SARS-CoV-2 in Spain and the existence of concomitant infections with other pathogens including T. gondii, L. infantum and FIV, suggesting that immunosuppressed animals might be especially susceptible to SARS-CoV-2 infection., (© 2021 Wiley-VCH GmbH.)

Immunocompromise is a common condition in cats, especially due to widespread infections with immunosuppressive viruses, such as feline immunodeficiency virus (FIV) and feline leukaemia virus (FeLV), but also due to chronic non-infectious diseases, such as tumours, diabetes mellitus, and chronic kidney disease, as well as treatment with immunosuppressive drugs, such as glucocorticoids, cyclosporins, or tumour chemotherapy. In this review, the European Advisory Board on Cat Diseases (ABCD), a scientifically independent board of experts in feline medicine from eleven European countries, discusses the current knowledge and rationale for vaccination of immunocompromised cats. So far, there are few data available on vaccination of immunocompromised cats, and sometimes studies produce controversial results. Thus, this guideline summarizes the available scientific studies and fills in the gaps with expert opinion, where scientific studies are missing. Ultimately, this review aims to help veterinarians with their decision-making in how best to vaccinate immunocompromised cats.

Objectives: The aim of this study was to describe the seroprevalence, presenting complaint, clinicopathological changes, co-morbidities and outcomes of feline leukemia virus positive cats presented to a specialty referral center in Florida, USA., Methods: In this retrospective study, medical records of 8050 cats presented to a private referral center from August 2008 to September 2019 were reviewed. Inclusion criteria required was a positive result for feline leukemia virus by point-of-care antigen testing or immunofluorescence assay., Results: Forty-one cases met the inclusion criteria. Of 2002 cats that were tested, 41 cats (2%) met the inclusion criteria. One cat had a negative point of care antigen test result and positive bone marrow IFA result. The mean age at diagnosis was 9 years. The main reasons for presentation were abnormal complete blood cell count results (35%), followed by pleural effusion (18%), and anorexia (15%). The most common laboratory abnormalities included anaemia (71%), of which 74% had a nonregenerative anemia, thrombocytopenia (52%), elevated aspartate aminotransferase (50%), hyperbilirubinemia (35%), and hypokalemia (35%). Seven percent of cats (3/41) were also positive for feline immunodeficiency virus. The most common diagnoses were neoplasia (76%) and bone marrow disorders (12%). Cats with neoplasia were significantly younger. Survival to discharge was 88%., Conclusion and Relevance: Results of this study show that feline leukemia virus is uncommon in secondary referral center, even if this represents a population of unhealthy cats. The most common associated diagnosis was neoplasia, which was more likely to be seen in younger cats (< 4 years of age). The mean age of cats positive for feline leukemia virus was also older than previously published data. These findings support the current guidelines which indicate that cats presented with clinical illness should be tested for FeLV at the time of presentation., Competing Interests: The authors have declared that no competing interests exist.

Objectives: The primary goal of this study was to characterize the clinical presentation of feline cutaneous lymphoma. The secondary aims included determining if treatment or initial response to treatment affected the overall survival of patients, and understanding if disease characteristics such as immunophenotype, cell size or the presence of epitheliotropism influenced response to treatment., Methods: Veterinary medical oncologists at four academic veterinary teaching hospitals submitted cases of feline patients with cutaneous lymphoma diagnosed by histopathology or cytology. Signalment, feline leukemia virus (FeLV)/feline immunodeficiency virus (FIV) status, physical examination findings, clinical signs, diagnostic tests, therapy, response and outcome, and necropsy findings, when available, were recorded., Results: Forty-one patients were identified and described. The majority of patients were domestic shorthair cats (n = 29). The median age at diagnosis was 12.3 years. Males were over-represented in the population (n = 30). In the majority of patients (n = 33), the FIV/FeLV status was unknown. Twenty patients were fully staged. Thirty-four patients were treated with a variety of modalities, including surgery, radiation, single-agent or combination chemotherapy, or prednisolone only. In multiple patients, surgery or radiation was combined with a systemic therapy. Of 34 patients treated with some form of therapy, 20 responded (achieving either a partial response or complete remission)., Conclusions and Relevance: Clinical signs and physical examination findings varied among patients. Response to therapy appeared to be associated with survival (P = 0.0025); however, this population was highly censored. Immunophenotype, cell size and the presence of epitheliotropism did not influence treatment response. Results were limited by small numbers of patients, heterogeneous disease manifestations and treatment protocols. Further studies are necessary to evaluate the effect of specific treatment modalities and disease subtype on prognosis.

Objectives: This study aimed to understand epidemiological factors associated with feline cystadenomatosis, including signalment and papillomavirus PCR status. Cystadenomatosis is an uncommon condition primarily involving the ceruminous and apocrine skin and ear glands., Methods: This was a retrospective case series. Clinical records from 2011 to 2019 from a tertiary referral hospital in Boston, MA, USA were screened for cases, and case data were re-evaluated and analyzed. The total patient pool contained 65,385 individual cats, of which 797 were referred to the dermatology service. Medical records and biopsy specimens were reviewed; the information collected included signalment, clinical signs, physical examination and diagnostic tests, comorbidities and histopathologic findings. PCR was performed on biopsy specimens to test for papillomavirus DNA., Results: The cystadenomatosis population consisted of 57 cases (7.1% of total cases referred to the dermatology service) with 105 affected ears. Twenty-seven cases (48 ears) were confirmed via histopathology; four cats (7%) exhibited clinically cystic lesions on the periocular, periorbital and perianal regions; only one cat did not have pinnal lesions. Domestic shorthair cats were most often affected. Relative risk for cystadenomatosis was 2.24 times higher in male cats. In 48 cats (84.2%), ears were bilaterally affected. Seven cats (12.3%) had malignant neoplasia, which included: inflamed adenocarcinoma (n = 5); mast cell tumor (n = 1); or squamous cell carcinoma (n = 1). PCR testing on biopsy specimens from 24 cats revealed feline papillomavirus type 2 DNA in only four cats., Conclusions and Relevance: Cystadenomatosis was more prevalent in senior non-purebred cats, over-represented in male cats and did not appear to be associated with papillomavirus, feline infectious peritonitis, feline immunodeficiency virus/feline leukemia virus status or other identifiable illnesses. Further studies are needed to investigate the causes of cystadenomatosis.

To evaluate the occurrence of feline immunodeficiency virus (FIV) and factors associated with this and to demonstrate occurrences of coinfection with Toxoplasma gondii and feline leukemia virus (FeLV) in cats, a total of 103 blood samples were collected from owned cats, during home visits. To diagnose FIV and FeLV, immunochromatographic kit was used and serological diagnoses of T. gondii, the indirect immunofluorescence test was performed. The occurrence of FIV-seropositive cats was 23.3% (24/103) and the factor associated with infection was male sex. T. gondii seropositivity of 53.4% (55/103) was observed and 75% of FIV cases (18/24) were positive for T. gondii coinfection. Only 0.9% (1/103) was positive for FeLV. It can be concluded that the seroprevalence of FIV in cats in the Brazilian semiarid region is high and that FIV positive cats were also likely to be T. gondii seropositive, while FeLV had very low occurrence in the study region., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Pneumonia in cats may cause severe lung injury and consequent death. We describe the post-mortem findings and aetiologies of naturally fatal pneumonia in 78 domestic cats, using gross and histopathological examinations, immunohistochemistry and microbiological techniques. Morphological patterns found were bronchopneumonia (27/78), interstitial (15/78), bronchointerstitial (13/78), granulomatous (8/78), aspiration (8/78) and pyogranulomatous (5/78) pneumonia, and pleuropneumonia (2/78). Bacterial pneumonia was identified as the most common cause (32/78), followed by viral (15/28 feline calicivirus, 10/28 felid alphaherpesvirus 1 and 3/28 both viruses), aspiration (8/78), fungal (5/78) and parasitic pneumonia (5/78). Co-infection with feline immunodeficiency virus and feline leukaemia virus was found in 54 cats. Viral infections involved cats of all ages, indicating the importance of investigating viral causes in cats with respiratory diseases, including in adult and ageing cats., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

An 11-year-old male mixed-breed cat, with exclusively indoor life, presented 3 cough episodes after the owners tested positive by RT-PCR for SARS-CoV-2. The house is inhabited by 5 people (3 adults and 2 children), and 2 of the adults have shown mild symptoms associated with throat discomfort. The cat was vaccinated, had no history of any previous disease, and tested negative for feline coronavirus (FCoV), feline immunodeficiency virus (FIV) and feline leukaemia virus (FeLV). Rectal sample collected from the cat was positive for SARS-CoV-2 by RT-PCR. Viral genome sequences recovered from human and cat samples showed an average 99.4% sequence identity. This is the first report of genome sequences of SARS-CoV-2 recovered from a cat and its owner in Latin America., (© 2021 Wiley-VCH GmbH.)

Feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV) are retroviruses causing significant morbidity and mortality in cats. The aim of this study was to describe the epidemiological, clinical and clinicopathologic aspects of FeLV and FIV infections in different populations of cats in Greece, including client-owned cats, stray cats and cats who live in catteries. A total of 435 cats were prospectively enrolled. Serological detection of FeLV antigen and FIV antibody was performed using a commercial in-house ELISA test kit. The results showed that 17 (3.9 %) and 40 (9.2 %) of the 435 cats were positive for FeLV antigen and FIV antibody, respectively, whereas 5 (1.1 %) had concurrent infection with FeLV and FIV. Factors that were associated with FeLV antigenemia, based on multivariate analysis, included vomiting, rhinitis, infection with FIV, neutropenia, decreased blood urea nitrogen and increased serum cholesterol and triglyceride concentrations. Factors associated with FIV seropositivity included male gender, older age, outdoor access, weight loss, fever, gingivostomatitis, skin lesions and/or pruritus and hyperglobulinemia. Various clinical signs and laboratory abnormalities were found to be significantly associated with retroviral infections, suggesting that current guidelines to test all sick cats should be followed, taking into particular consideration the high-risk groups of cats found in this study., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Feline calicivirus (FCV), feline alphaherpesvirus 1 (FHV-1) and feline panleukopenia virus (FPLV) as well as retroviral agents such as feline leukaemia virus (FeLV) and feline immunodeficiency virus (FIV) are important viral pathogens of cats. The aim of this study was to detect and characterise FHV-1, FPLV, FeLV, FIV and feline foamy virus (FFV) in oropharyngeal, nasal and conjunctival swabs from 93 cats that had been screened for FCV previously. We wanted to determine the possible risk factors for infection with these viruses. The prevalence was found to be 12.9% for FHV-1 and 9.7% for FPLV. FIV was detected only in two samples and FeLV in one sample, whereas the presence of FFV was not demonstrated in any of the clinical samples. The statistical analysis of the results showed that breed, age, health status, and lifestyle are important predisposing factors to FHV-1 (P < 0.05). For FPLV, only clinically unhealthy animals were found to be at risk (P < 0.001). Sequence analysis revealed that the two FIV-positive samples in this study contained different (A and B) subtypes of the virus. This is the first report on the occurrence of subtype A FIV in Turkey.

Feline haemoplasma infection studies are lacking in Russia. This retrospective study was conducted to estimate the prevalence of feline haemoplasmas in domestic cats in the Moscow region, Russia. A risk of haemoplasma coinfection with feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV) was also determined. qPCR analysis for feline haemoplasmas was performed on EDTA blood samples from 753 cats from the Moscow region, Russia. Subsets of these samples were tested also for FIV and FeLV by qPCR. Of the 753 blood samples, 104 (13.8 %) were positive for one of the Mycoplasma species. The prevalence of 'Candidatus Mycoplasma haemominutum' (CMhm), Mycoplasma haemofelis (Mhf), and 'Candidatus Mycoplasma turicensis' (CMt) was 7.6 %, 5.5 %, and 0.7 %, respectively. One sample (0.1 %) was simultaneously infected with two haemoplasmas, namely, Mhf and CMt. Haemoplasma positive cats were more likely to be infected with FIV than haemoplasma negative (17.6 % vs 6.7 %), but these differences were not statistically significant. The prevalence of FeLV was comparable among haemoplasma positive and negative cats (23.5 % vs 25.7 %) All three known species of feline haemoplasma were detected, confirming their presence in Russia. The overall and species-specific rates of haemoplasma infections in Russian cats are generally similar to the rates in the countries of central Europe. This report documents for the first time the prevalence of feline hemotropic mycoplasmas in domestic cats not only in Russia but also in eastern Europe., (Copyright © 2021 Elsevier B.V. All rights reserved.)