Clinical, Echocardiographic and Cytological Characteristics of Pericardial Pathologies Accompanied by Pericardial Effusion in Dogs

Introduction. The majority of pericardial diseases are accompanied by pathological accumulation of fluid in the pericardial cavity (effusion), as well as cardiac tamponade. Physical examination methods combined with transthoracic echocardiography are widely used to diagnose these conditions. An important task for veterinary specialists is to determine characteristic symptoms and specific echocardiographic signs of cardiac tamponade, which is considered to be a life-threatening condition. Cytological examination of pericardial fluid is an integral part in diagnosing the cause of the effusion. A comprehensive approach to diagnosis underpins the efficiency of treatment strategies. The existing studies poorly reveal the relationships between the clinical symptoms and echocardiographic signs, which could enable the diagnosis of disease severity and its prognosis, neither do they fully elucidate the cytological characteristics of effusions that could indicate the causes of effusion occurrence. The aim of the study is to establish the clinical, echocardiographic, and cytological relationships in dogs with pericardial pathologies accompanied by pericardial effusion.
Materials and Methods. The study was conducted at the Department of Veterinary Surgery of Moscow State Academy of Veterinary Medicine and Biotechnology – MVA named after K. I. Skryabin and at the Veterinary Research Center “Biocontrol” in the period from 2018 to 2023. The objects under study were dogs of various breeds, ages, and sexes (n=200). The examination methodology included: collection of patient’s medical history, clinical examination, echocardiography, electrocardiography, chest radiography, ultrasonographic visualization of free fluid in the thoracic and abdominal cavities, pericardiocentesis, cytological examination of effusion, and histological examination of pathological material obtained during surgery.
Results. During the echocardiography, a ring-shaped anechoic space of varying diameter was revealed around the heart in all the studied dogs with pericardial effusion. Of 200 patients, cardiac tamponade was registered in 64 animals (32.0%), to whom pericardiocentesis was performed. For further determination of the causes of pericardial effusion, cytological examination of the obtained fluid was performed in 61 patients. According to cytomorphological characteristics, the following types of effusion were identified: transudate (1.6%), modified transudate (4.9%), septic exudate (1.6%), hemorrhagic effusion (which, in turn, was divided into effusion corresponding to: acute hemorrhage (4.9%), chronic hemorrhage (77.0%), hemorrhagic effusion with cytological signs of a tumor (9.8%)).
Discussion and Conclusion. In the presence of pericardial effusion, detection of the cardiac tamponade syndrome is of great clinical importance. We have established the most common echocardiographic signs of tamponade: caudal vena cava dilation and reduction of its collapsibility amplitude to less than 50%, as well as right atrial collapse. A relationship between the clinical symptoms (abdomen volume increase due to accumulation of ascitic fluid, progressing weakness, and exercise tolerance decrease) and echocardiographic signs of cardiac tamponade was revealed. Based on cytological examination results, the hemorrhagic type of pericardial effusion was identified as the most common one, concomitant to cardiac and pericardial tumors in older dogs of medium and large breeds.

1. Enders М, Sarani N, Malik А. Isolated Left Ventricular Cardiac Tamponade Diagnosed on Point-of-Care Ultra-sound in the Emergency Department: A Case Report and Brief Literature Review. Journal of the American College of Emergency Physicians Open. 2023;4(4):e12990. https://doi.org/10.1002/emp2.12990

2. Hanson M, Chan B. The Role of Point-of-Care Ultrasound in the Diagnosis of Pericardial Effusion: A Single Academic Center Retrospective Study. Ultrasound Journaal. 2021;13:2. https://doi.org/10.1186/s13089-021-00205-x

3. Kokulenko KV, Kostylev VA, Goncharova AV. Echocardiographic Characteristics of Pericarditis in Small Domestic Animals. In: Proceedings of the 12th International Interuniversity Conference on Clinical Veterinary Medicine in the Partners Format. Moscow, November 17–18, 2022. Moscow: Selskokhozyaistvennye tekhnologii Publ.; 2022. P. 589–593. (In Russ.).

4. Klein А, Chair, Abbara S., MD, Agler D., Appleton CP, Asher CR, Hoit B, et al. American Society of Echocardiography Clinical Recommendations for Multimodality Cardiovascular Imaging of Patients with Pericardial Disease: Endorsed by the Society for Cardiovascular Magnetic Resonance and Society of Cardiovascular Computed Tomography. Journal of the American Society of Echocardiography. 2013;26:965-1012.e15. https://doi.org/10.1016/j.echo.2013.06.023

5. Arutyunov GP, Paleev FN, Tarlovskaya EI, Moiseeva OM, Arutyunov AG, Koziolova NA, et al. Pericarditis. Clinical Guidelines 2022. Russian Journal of Cardiology. 2023;28(3):5398. (In Russ.). https://doi.org/10.15829/1560-4071-2023-5398

6. Adler Y, Charron P, Imazio M, Badano L, Barón-Esquivias G, Bogaert J, et al. 2015 ESC Guidelines for the Diag-nosis and Management of Pericardial Diseases: The Task Force for the Diagnosis and Management of Pericardial Diseases of the European Society of Cardiology (ESC) Endorsed by: The European Association for Cardio-Thoracic Surgery (EACTS). European Heart Journal. 2015;36(42):2921–2964. https://doi.org/10.1093/eurheartj/ehv318

7. Chiabrando JG, Bonaventura A, Vecchié A, Wohlford GF, Mauro AG, Jordan JH, et al. Management of Acute and Recurrent Pericarditis: JACC State-of-the-Art Review. Journal of the American College of Cardiology. 2020;75(1):76–92. https://doi.org/10.1016/j.jacc.2019.11.021

8. Ming Wang ТK, Klein А. Multi-Modality Cardiac Imaging for Pericardial Diseases: A Contemporary Review. Reviews in Cardiovascular Medicine. 2022;23(10):336. https://doi.org/10.31083/j.rcm2310336

9. Alerhand S, Adrian RJ, Long B, Avila J. Pericardial Tamponade: A Comprehensive Emergency Medicine and Echocardiography Review. American Journal of Emergency Medicine. 2022;58:159–174. https://doi.org/10.1016/j.ajem.2022.05.001

10. Kokulenko KV, Goncharova AV, Kostylev VA. Clinical Characteristics of Dogs with Pericardial Pathologies Accompanied by Pericardial Effusions. Legal Regulation in Veterinary Medicine. 2024;(3):63–66. (In Russ.). https://doi.org/10.52419/issn2782-6252.2024.3.63

11. MacDonald KA, Cagney O, Magne ML. Echocardiographic and Clinicopathologic Characterization of Pericardial Effusion in Dogs: 107 Cases (1985–2006). Journal of the American Veterinary Medical Association. 2009;235(12):1456–1460. https://doi.org/10.2460/javma.235.12.1456

12. Cagle LA, Epstein SE, Owens SD, Mellema MS, Hopper K, Burton AG. Diagnostic Yield of Cytologic Analysis of Pericardial Effusion in Dogs. Journal of Veterinary Internal Medicine. 2014;28(1):66–71. https://doi.org/10.1111/jvim.12253

13. Scheuermann L, Gordon-Evans W, Nault A. Systematic Review of the Treatment Options for Pericardial Effu-sions in Dogs. Veterinary Surgery. 2021;50(1):20–28. https://doi.org/10.1111/vsu.13475

14. Gunasekaran Т, Olivier N, Smedley R, Sanders R. Pericardial Effusion in a Dog with Pericardial Hemangiosarcoma. Journal of Veterinary Cardiology. 2019;23:81–87. https://doi.org/10.1016/j.jvc.2019.01.008

15. Kokulenko KV, Goncharova AV, Kostylev VA. Risk Factors for the Occurrence and Development of Pericardial Effusions in Dogs. Veterinary, Zootechnics and Biotechnology. 2023;(8):35–41. https://doi.org/10.36871/vet.zoo.bio.202308004

16. Köster L, Newkirk K, Krawec P. A Case Report: Null-Cell Cardiac Lymphoma in An English Bulldog. Frontiers in Veterinary Science. 2024;11:1256442. https://doi.org/10.3389/fvets.2024.1256442

17. Treggiari E, Pedro B, Dukes-McEwan J, Gelzer AR, Blackwood L. A Descriptive Review of Cardiac Tumours in Dogs and Cats. Veterinary and Comparative Oncology. 2017;15(2):273–288. https://doi.org/10.1111/vco.12167

18. MacGregor JM, Faria ML, Moore AS, Tobias AH, Brown DJ, de Morais HS. Cardiac Lymphoma and Pericardial Effusion in Dogs: 12 Cases (1994–2004). Journal of the American Veterinary Medical Association. 2005;227:1449–1453. https://doi.org/10.2460/javma.2005.227.1449

19. Stafford Johnson M, Martin M, Binns S, Day MJ. A Retrospective Study of Clinical Findings, Treatment and Out-come in 143 Dogs with Pericardial Effusion. Journal of Small Animal Practice. 2004;45:546–552. https://doi.org/10.1111/j.1748-5827.2004.tb00202.x

20. Yamamoto S, Hoshi K, Hirakawa A, Chimura S, Kobayashi M, Machidaet. Epidemiological, Clinical and Pathological Features of Primary Cardiac Hemangiosarcoma in Dogs: A Review of 51 Cases. Journal of Veterinary Medical Science. 2013;75(11):1433–1441. https://doi.org/10.1292/jvms.13-0064

21. Griffin М, Culp WTN, Rebhun RB. Canine and Feline Haemangiosarcoma. Veterinary Record. 2021;189(9):е585. https://doi.org/10.1002/vetr.585

22. Wakamatsu СN, Potter ВM, Leary D, Boss M, Martin TW. Retrospective Study Evaluating Outcomes Following Palliative Radiotherapy with or without Chemotherapy for Dogs with Presumed Cardiac Hemangiosarcoma. Veterinary and Comparative Oncology. 2025;23(3):432–441. https://doi.org/10.1111/vco.13068