Journal of Feline Medicine and Surgery最新文献

Objective: Feline infectious peritonitis (FIP) can be treated with antiviral agents such as remdesivir and GS-441524, with a commonly used treatment duration of 12 weeks. Although serum amyloid A (SAA) and alpha-1 acid glycoprotein (α1AG) have been proposed as markers of disease improvement, criteria for treatment cessation before this duration remain unclear. This study evaluated whether SAA and α1AG could guide treatment cessation in cats with FIP and whether a high-dose induction protocol could allow shortening of treatment duration.

Methods: Thirty cats with FIP, excluding those presenting solely with neurological signs, received high-dose (≥20 mg/kg) therapy using injectable remdesivir followed by oral GS-441524 or oral GS-441524 alone. Remdesivir was administered once daily, whereas GS-441524 was given as the total daily dose divided into two doses 12 hours apart. After initial improvement, the dose was reduced to the maintenance dose of 12-15 mg/kg based on clinical signs. Clinical signs, serum SAA and α1AG were monitored. Treatment was discontinued when clinical signs resolved and both SAA <6 mg/L and α1AG ≤0.5 g/L were maintained for at least two consecutive weeks before 12 weeks, or at 12 weeks regardless of these criteria.

Results: Twenty-nine of 30 cats (96.7%) survived. Among these, 22 cats (75.9%) met the treatment termination criteria within 12 weeks (median treatment duration: 54 days [range: 41-71 days]), whereas seven completed 12 weeks. No relapse was observed during treatment or within the 3-month follow-up period.

Conclusions and relevance: Although high-dose induction therapy is not a standard protocol, no clear adverse effects were observed, and treatment could be discontinued before 12 weeks in some cats. In cats in which treatment was shortened, improvement in SAA and α1AG concentrations appeared to be useful indicators for guiding treatment cessation. Further studies are required to clarify the clinical benefit of high-dose induction therapy.

Objectives: This study aimed to compare the influence of two burr types on surgical time during percutaneous endoscopic mini-hemilaminectomy (PE-MHL) in feline cadavers.

Methods: Twelve skeletally mature domestic shorthair cat cadavers underwent bilateral PE-MHL at L4-L5 using either a diamond or a cutting burr in alternating order. Surgical duration, surgical side, postoperative computed tomographic bone window area and the percentage of lamina removed were compared. Approximately 30% laminar removal was targeted. Data were expressed as mean ± standard error of the mean (SEM) and analyzed using Shapiro-Wilk and Levene's tests, followed by Student's t-tests (P ≤ 0.05).

Results: All procedures were completed successfully. Procedure time was significantly shorter with the diamond burr (20.85 ± 1.44 minutes) than with the cutting burr (25.62 ± 1.49 minutes; P = 0.03). The surgical side had no significant effect on any parameter. Bone window areas were comparable between burrs (68.42 ± 2.02 mm² vs 63.92 ± 3.19 mm²; P = 0.27). The overall mean of lamina removed was 32.38 ± 2.31%, closely matching the intraoperative target. Three cutting burrs broke, whereas no failures occurred with diamond burrs.

Conclusions and relevance: Both burr types were effective for PE-MHL in feline cadavers. The diamond burr enabled more efficient, precise and controlled bone removal, resulting in smoother bone margins and consequently reduced procedure times. These findings suggest that the diamond burr may be a more reliable instrument for controlled bone removal under endoscopic conditions and provide the basis for future in vivo studies.

ObjectivesThis exploratory study aimed to evaluate the methaemoglobin fraction in cats with sepsis, non-septic sick counterparts and healthy controls, and to assess the feasibility of using the methaemoglobin fraction as a biomarker for predicting clinically relevant outcomes such as duration of hospitalisation and mortality.MethodsMedical records were retrospectively searched for all cases of confirmed sepsis presenting to the ICU of two referral hospitals, from September 2016 to January 2019 in Institution A and March 2019 and October 2024 in Institution B, with a methaemoglobin measurement taken on admission. Records were also searched for cats presenting to the ICU of Institution B from March 2019 to October 2024 who met 2/4 SIRS criteria without evidence of infection. The methaemoglobin levels of these cases and those of previously collected data from healthy cats (from both institutions) were compared to those of the septic population. Data from each institution was analysed separately.ResultsA total of 47 cats with sepsis were enrolled (23 in Institute A and 24 in Institute B), as well as 100 NSS cats from Institute B and 53 healthy controls (42 in Institute A and 11 in Institute B). Data from each Institute was analysed separately. The median methaemoglobin fraction was significantly higher in control cats compared to septic cats in institution A (1.7%, 0.1-2.6% vs 1.1%, 0.1-6.9%, P = 0.03). There was no significant difference in methaemoglobin levels between combined septic survivors vs non-survivors (0.5%, 0.2-6.9% vs 0.9%, 0.1-3.6%, P = 0.5).Conclusions and relevanceThis exploratory study was unable to demonstrate a significantly increased circulating methaemoglobin fraction in cats with sepsis or an association between methaemoglobin fraction and survival outcome. These findings support the feasibility of further research and highlight the need for adequately powered standardised multicentre studies to clarify the biomarker's clinical utility.

Case Series SummaryFatal feline infectious peritonitis (FIP), caused by feline coronavirus (FCoV), can now be cured with GS-441524. Only a few unexpected clinical and laboratory observations have been reported with treatment, including lymphocytosis, eosinophilia and long-term persistence of abdominal lymphadenomegaly. Yet immune overstimulation associated with FIP might have negative long-term consequences. This report describes four cases of large cell lymphoma (LCL) arising within 2 years after FIP diagnosis and successful treatment with legally sourced oral GS-441524 (15 mg/kg once daily), representing an incidence of 2.0% (4/202) in a large treatment cohort. At LCL diagnosis, two cats were <2 years old, one was 9 years old and one was 13 years old. All cats showed weight loss, three had hyporexia and two had chronic vomiting; all were feline leukemia virus and feline immunodeficiency virus negative. LCL was diagnosed by histology (n = 3) or cytology (n = 1) at 81, 365 (n = 2) and 595 days after FIP diagnosis/treatment start. The cats died a median of 15.5 days after LCL diagnosis. Neither a high FCoV viral load nor FCoV antigen, as determined by semiquantitative reverse transcriptase polymerase chain reaction (RT-qPCR) and immunohistochemistry, respectively, was detected in any of the available samples. PCR for antigen receptor rearrangements revealed a monoclonal B cell population in two cats, supporting a diagnosis of LBCL.Relevance and Novel InformationThe incidence of LCL reported here among cats in remission from FIP after legally sourced oral GS-441524 treatment is remarkably high compared to the general feline population. LCL should be considered a potential "long-FIP syndrome" and/or a long-term complication after GS-441524 treatment. The pathogenesis of LCL in this context requires further clarification.

ObjectivesFeline coronavirus (FCoV) is widely acknowledged to gain pathogenicity within-host to cause the lethal disease feline infectious peritonitis (FIP). Most FIP cases are caused by viruses in genotype 1 (FCoV-1) via an 'internal mutation' in the spike gene. Genotype 2 (FCoV-2) has risen to prominence based on the emergence of FCoV-23, a highly pathogenic novel variant from Cyprus that has a deletion in the N-terminus (domain 0) of spike. In this study, we conducted a retrospective analysis of three cases of FCoV-2 in the U.S.: two (#344 and #346) from 2013 and one (#597) from 2016. Cats #344 and #597 exhibited clinical signs consistent with FCoV infection for at least 2 months. The third cat (#346), the daughter of #344, was euthanized shortly after showing signs.MethodsWe collected a total of 20 tissue, fluid, and fecal samples from the three cats. We characterized the FCoV-2 in these samples using whole-genome sequencing, genetic and phylogenetic analyses, and viral RNA quantification.ResultsWhole-genome sequencing revealed that the two cats exhibiting long-term signs of FIP (#344 and #597) each had a distinct deletion in domain 0 of spike, which was present in all examined tissues. Cat #346, the daughter of #344, which only displayed signs for a short period, had an intact (or long) spike gene. Low RNA titers of the FCoV-2 with the short version were detected in the feces of cats #344 and #597 (2.52 to 5.28 RNA copies/μl).Conclusions and relevanceOur data are consistent with a model whereby FCoV-2 displaying the long version of S is transmitted between cats, while the short version is generated within each cat after a prolonged infection and spreads rapidly throughout the body. We suggest that the high pathogenicity of FCoV-2 is associated with an "internal deletion" in the spike gene.

Objectives: To investigate the effects of high-dose carvedilol treatment (HD) in client-owned cats with Stage B1 obstructive hypertrophic cardiomyopathy (oHCM) where standard-dose (SD) had failed to adequately alleviate left ventricular outflow tract obstruction (LVOTO).

Methods: A prospective, interventional study was conducted in which cats underwent echocardiography, including evaluation of myocardial strain using speckle-tracking echocardiography. Myocardial injury was quantified using a cTnI assay. Echocardiographic variables and the cTnI level were compared, pre-treatment, and post SD and HD.

Results: Although, LVOT velocity (LVOTV) decreased post SD compared to pre-treatment in all cats, but remained >2.5 m/s post SD (pre-treatment, 4.9 [4.3-5.0] m/s; SD, 4.3 [3.9-4.7] m/s). Whereas HD decreased LVOTV to <2.5 m/s in 10/11 cats (1.6 [1.5-2.0] m/s). Longitudinal strain was improved post SD and HD compared to that pre-treatment (endocardial layer: pre-treatment, 12.1 [9.6-15.8] %; SD, 20. 0 [15.9-21.7] %, HD, 18.9 [12.9-22.8] %, P =0.003 and P =0.006, respectively; epicardial layer: pre-treatment, 9.4 [7.0-10.7] %; SD, 11.6 [10.0-12.7] %, HD, 12.5 [10.0-13.3] %, P =0.013 and P =0.001, respectively). Circumferential strain demonstrated no changes. The cTnI level decreased after SD and HD compared to pre-treatment, and HD compared to SD (pre-treatment, 0.334 [0.117-0.931] ng/mL; SD, 0.192 [0.111-0.377] ng/mL; and HD, 0.018 [0.009-0.161] ng/mL; P =0.043, P =0.043, and P =0.043 respectively). No cats experienced adverse effects such as bradycardia or hypotension.

Conclusions and relevance: HD improved LVOTV, myocardial function, and cTnI level without adverse effects in cats with Stage B1 oHCM.

Objectives: To characterise the three-dimensional external and internal morphology of the feline tibia, including bone length, external and internal diameters, cortical thickness, cancellous bone volume, and mechanical joint angles, using computed tomography (CT).

Methods: Eight paired tibiae from adult domestic feline cadavers were evaluated using CT imaging. Morphometric parameters-including bone length, external and internal diameters, cortical thickness, cancellous bone volume, and mechanical joint angles-were measured in triplicate for each bone. The mean of each set of triplicate measurements was recorded for analysis.

Results: Overall tibia length measured 111.61mm (95% CI 107.89 - 115.53mm). The narrowest internal bone diameter mediolaterally was at 50% tibial length (4.23mm 95% CI 4.05 - 4.42mm) and craniocaudally at 75% tibial length (3.77mm 95% CI 3.57 - 3.97mm). Thickness of the cranial and caudal cortex was thickest at 50% of tibial length. The proximal tibia had a mean cancellous bone volume of 12.45mm3 (95% CI 11.4 - 13.49mm3). The distal tibia had a mean cancellous bone volume of 2.09mm3 (95% CI 1.62 - 2.55mm3). Mean mechanical joint angles and 95% CI were: tibial plateau angle 31.42□ (30.09 - 32.75□); mechanical medial proximal tibia angle 95.15□ (94.63 - 95.68□); mechanical medial distal tibia angle 94.08□ (93.36 - 94.79□); mechanical cranial distal tibia angle 88.69□ (87.04 - 90.32□); mechanical caudal proximal tibia angle 58.53□ (57.20 - 59.86□) and sagittal plane alignment 30.16□ (28.47 - 31.84□).

Conclusions and relevance: The use of computed tomography allowed for the estimation of internal bone morphometry and joint geometry in feline tibias. This provided data that may be valuable in planning and developing new techniques for internal fracture fixation in cats.

Objectives: Feline infectious peritonitis (FIP) is a fatal disease caused by feline coronavirus. The nucleoside analog GS-441524, the parent nucleoside of remdesivir, is the most commonly used FIP antiviral. Remdesivir is FDA approved to treat COVID-19 in humans and has been used primarily as an adjunctive treatment for FIP. This study compares the effectiveness of oral remdesivir versus GS-441524 as a first-line antiviral therapy for cats with non-effusive FIP in a prospective, randomized, double-blind, noninferiority clinical trial.

Methods: Cats with non-effusive FIP were randomly assigned to receive either oral remdesivir (38-42mg/kg, n=10) or oral GS-441524 (18-22mg/kg, n=10) once daily for 84 days (12 weeks). Follow-up was conducted at 6 and 16 weeks, and response to therapy, survival, and disease-free remission were assessed. Long-term follow-up was also obtained by contacting owners 1.5-2 years after conclusion of the study.

Results: At week 16, 9/10 (90%) of cats treated with remdesivir and 7/10 (70%) treated with GS-441524 were alive and in clinical remission. The difference in survival and remission between the two treatment groups was 20% (90% confidence interval, -8.5 - 48.5%). All deaths during treatment occurred within the first 11 days of the trial. Long-term follow-up revealed new onset of clinical signs and raised concerns for potential late relapse of disease in 4 cats (2 in each group).

Conclusions and relevance: GS-441524 and remdesivir are both effective treatment options for non-effusive FIP. However, further assessment of cats previously treated for non-effusive FIP is warranted to determine the rates of relapse and how best to manage them.

Objectives: Ultrasonography plays a crucial role in diagnosing feline renal diseases, including neoplasia. The aims of this study were to describe ultrasonographic features of renal neoplasia in cats and to investigate potential differences between tumor types.

Methods: In this multicenter retrospective study, ultrasonographic images of feline kidneys with cytologically/histologically confirmed renal neoplasia were reviewed. For each kidney, ultrasonographic characteristics (renal length, presence and appearance of a mass, nodules, hypoechoic subcapsular rim, pelvic distension, retroperitoneal effusion) were recorded and compared for each tumor type.

Results: 187 cats (373 kidneys) were included. Tumor types were lymphoma (n=118, 63%), carcinoma (n=53, 28.5%), sarcoma (n=10, 5%), adenoma (n=3, 2%), histiocytic sarcoma (n=2, 1%), and nephroblastoma (n=1, 0.5%). Bilateral disease (p<0.001) and other organ involvement (p=0.026) were more frequent in lymphoma. A single mass was more frequent in carcinoma (p<0.001). Masses were more frequently hypoechoic in lymphoma (81%) and sarcoma (86%) than in carcinoma (40%) (p=0.001). In kidneys with masses, a hypoechoic subcapsular rim was more frequent in lymphoma (p=0.004). In kidneys without mass lesions, kidneys with lymphoma (51.3+/- 9.8 mm) were significantly larger (p=0.02) than those with carcinoma (46.1 +/- 6.4 mm) and sarcoma (42.8 +/- 8.9 mm).

Conclusions and relevance: Lymphoma was the most common renal neoplasia, followed by carcinoma. Some ultrasonographic features, including bilateral involvement, single masses, multiple nodules, hypoechoic subcapsular rim, and severity of nephromegaly, can help differentiate feline renal tumor types.

ObjectivesThe Lykoi is a recently recognised feline breed with a unique coat phenotype caused by six variants of the Hairless (HR) gene. A specific severe cutaneous comedonal syndrome has been reported in this breed. The aim of the study was to carry out a clinical, histopathological and genetic characterisation of this syndrome.MethodsProspective data collection included clinical evaluation, skin biopsies for histopathology, trichoscopic examination of hair shafts, blood sampling for haematology and biochemistry, cutaneous swabs for bacteriological culture, and buccal swabs for DNA extraction and genotyping.ResultsIn total, 11 privately owned Lykoi cats were enrolled, including those with varying degrees of skin involvement and one healthy cat. Cats were aged 1.5-7 years at the time of diagnosis. Clinical presentation was characterised by papular lesions and comedones, ranging from severe generalised forms (n = 6/10) to moderate regional forms (n = 2/10) and to mild scattered forms (n = 2/10). Histopathological lesions from skin biopsies revealed infundibular follicular cysts (n = 9/10), sebaceous gland (duct) cysts (n = 10/10) and sweat gland cysts (n = 5/10). Genetic analysis identified 5/6 described HR variants among the 10 affected Lykoi and the control Lykoi.Conclusions and relevanceThis cutaneous syndrome shows a variable clinical severity that is not fully explained by genotype alone. The consistent presence of cysts from all three adnexal structures, even in clinically unaffected skin, supports the recognition of a novel skin condition, which we propose to name cutaneous adnexal polycystic syndrome (CAPS) in Lykoi cats. Further research is needed to elucidate its pathogenesis.