Feline infectious peritonitis (FIP) caused by feline coronavirus (FCoV) is a fatal disease in cats characterized by variable manifestations. Myocarditis represents a less commonly described pathology within the clinical spectrum of FIP. No research has described the successful treatment of FIP-induced myocarditis. In this study, 40 cats were included and treated with 15 mg/kg of GS-441524 every 24 h orally. All cats were diagnosed with FIP by reverse transcription quantitative PCR in effusion in combination with typical clinical and laboratory changes. Echocardiography was performed in all cats, and myocarditis was suspected in 4/40 cats. Equivocal wall thickness was diagnosed in 2/4 cats, while systolic dysfunction with biatrial dilation was diagnosed in the other 2/4 cats. One cat also presented with ventricular ectopy. A severe increase in cardiac troponin I was seen in all four cats (median 1.82 ng/mL (1.20–5.84 ng/mL)). Cardiac dimensions and electrocardiographic abnormalities completely normalized in all four cats during treatment with GS-441524 and remained stable after treatment discontinuation during a one-year follow-up period. Myocarditis can be a clinical feature of FIP and present with different cardiologic manifestations. FIP-induced myocarditis can be cured with GS-441524 in combination with symptomatic cardiovascular treatment including pimobendan, clopidogrel, furosemide, or atenolol, depending on the clinical presentation.

The assessment of left ventricular myocardial deformation and function by two-dimensional speckle tracking-derived strain analysis is an established method in human cardiology. It also progressively gains recognition in veterinary cardiology in both dogs and cats. The objectives of this study were to create reference intervals for two-dimensional speckle tracking echocardiography (STE)-derived endocardial global longitudinal strain (GLS) in a population of healthy adult cats of different breeds. Influences of heart rate, body weight, and age were investigated. A total of 132 healthy, adult cats were included in this study. Left apical two-, three-, and four-chamber views were obtained prospectively for GLS measurements using two-dimensional speckle tracking performed with cardiac performance analysis. Potential influence of body weight, heart rate, and age was analyzed, and the interobserver and intra-observer variability of the measurements was determined. Endocardial GLS values were not significantly influenced by body weight (P=0.102), heart rate (P=0.144), or age (P=0.075). A reference interval for GLS of -21.18% to -37.50% (±4.12) was determined. The interobserver and intra-observer variability showed excellent agreement. Two-dimensional STE is a feasible technique for the evaluation of cardiac myocardial deformation and systolic function in cats. Showing an excellent interobserver and intra-observer agreement, two-dimensional STE is a promising method for clinical analysis of cardiac deformation in cats.

Background: Dilated cardiomyopathy (DCM) in Doberman Pinschers (DPs) often initially manifests as ventricular arrhythmias (stage B1) without echocardiographic evidence of cardiac remodeling (stage B2). Global longitudinal strain (GLS) is a sensitive echocardiographic variable for detecting early systolic dysfunction. Hypothesis/Objectives: To assess whether GLS detects systolic dysfunction in DPs with arrhythmogenic stage B1 and to evaluate the association between arrhythmic burden and GLS. Animals: Sixty-three DPs with arrhythmogenic stage B1 DCM and 63 control DPs. Methods: Retrospective case–control study. Stage B1 was defined as ≥300 ventricular premature complexes (VPCs) within 24 h or >50 VPCs on two 24-h Holter recordings within 1 year, with otherwise normal echocardiographic measurements. Forty-three dogs had “last-normal” (LN) examinations 6-12 months before arrhythmia onset. GLS was measured using 2-dimensional speckle-tracking echocardiography (STE) from left apical 2-, 3-, and 4-chamber views. Stage B1 dogs were subclassified into low-grade (LGvpc) and high-grade (HGvpc) groups based on arrhythmic burden. Results: GLS was lower in stage B1 dogs (mean ± SD, −16.80% ± 2.71%) compared to controls (−20.22% ± 1.90%; P = .044). Stage B1 dogs had lower GLS compared to their LN examinations (mean difference, −2.45%; 95% CI, −3.67% to −1.24%; P < .001). Dogs in the HGvpc group had lower GLS (−15.45% ± 2.79%) than LGvpc dogs (−18.39% ± 1.51%; mean difference, −2.94%; 95% CI, −4.28% to −1.60%; P < .001). Conclusions: GLS detects systolic dysfunction in DPs with arrhythmogenic stage B1 DCM despite normal conventional echocardiographic measurements. Higher arrhythmic burden is associated with more severe systolic dysfunction.