**5. Conclusions**

These results provide evidence for increased endocardial vWF in cats with advanced cardiomyopathy and support a potential role for endocardial vWF as a pro-thrombotic substrate.

**Supplementary Materials:** The following are available online at https://www.mdpi.com/article/ 10.3390/ani11051240/s1, Figure S1: Gross appearance of the thrombi. Table S1: Pathology classification criteria for feline cardiomyopathies, Table S2: Echocardiographic classification criteria for feline cardiomyopathies, Table S3: Clinical presentation and echocardiography summary, Table S4: Signalment, echocardiographic parameters, and histopathology diagnosis, Table S5: Measurement of echocardiographic variables. References [33,36,38,39] are also cited in the supplementary materials.

**Author Contributions:** W.-C.C. contributed to the design of the study and performed the majority of the laboratory work. She also analysed the results and wrote the manuscript. L.W. performed the gross and histopathology on the specimens and contributed to writing the manuscript. T.A.K. contributed to the design of the study and some of the laboratory work as well as contributing to writing the manuscript. M.D. performed the gross and histopathology on the specimens and contributed to writing the manuscript. S.L.P. contributed to the design the study and to writing the manuscript and gave editorial advice. V.L.F. contributed to the design of the study and to writing the manuscript and gave editorial advice. D.J.C. was involved in study design and day to day supervision of the study as well as a primary contributor to the manuscript and its subsequent edits. All authors have read and agreed to the published version of the manuscript.

**Funding:** The author Wan-Ching Cheng received funding from Taiwan Ministry of Education.

**Institutional Review Board Statement:** The study was and approved by the Ethics Committee of the Royal Veterinary College—approval number URN 2014 1301.

**Data Availability Statement:** The data presented in this study are available on request from the corresponding author. The data are not publicly available due to privacy issues.

**Acknowledgments:** We would like to acknowledge Yu-Mei Ruby Chang and Elisabeth Ehler for the assistance and advice with the statistical analysis and immunostaining, respectively.

**Conflicts of Interest:** The authors declare no conflict of interest.
