• 1. Sisson D, Kvart C, Darke P. Acquired valvular heart diseases of dogs and cats. In: Fox PR, Sisson D, Moise NS, eds. Textbook of canine and feline cardiology principles and clinical practice. 2nd ed. Philadelphia: Saunders, 1999;536565.

    • Search Google Scholar
    • Export Citation
  • 2. Pedersen HD, Lorentzen KA, Kristensen BO. Echocardiographic mitral valve prolapse in Cavalier King Charles Spaniels: epidemiology and prognostic significance for regurgitation. Vet Rec 1999; 144: 315320.

    • Search Google Scholar
    • Export Citation
  • 3. Brown CH 3rd, Leverett LB, Lewis CW, et al. Morphological, biochemical, and functional changes in human platelets subjected to shear stress. J Lab Clin Med 1975; 86: 462471.

    • Search Google Scholar
    • Export Citation
  • 4. Tanaka R, Yamane Y. Platelet aggregation in dogs with mitral valve regurgitation. Am J Vet Res 2000; 61: 12481251.

  • 5. Michelson AD. Platelet function testing in cardiovascular diseases. Circulation 2004; 110:e489e493.

  • 6. Tarnow I, Kristensen A, Olsen LH, et al. Assessment of changes in hemostatic markers in Cavalier King Charles Spaniels with myxomatous mitral valve disease. Am J Vet Res 2004; 65: 16441652.

    • Search Google Scholar
    • Export Citation
  • 7. Tarnow I, Kristensen AT, Texel H, et al. Decreased platelet function in Cavalier King Charles Spaniels with mitral valve regurgitation. J Vet Intern Med 2003; 17: 680686.

    • Search Google Scholar
    • Export Citation
  • 8. Tarnow I, Kristensen AT, Olsen LH, et al. Dogs with heart diseases causing turbulent high-velocity blood flow have changes in platelet function and von Willebrand factor multimer distribution. J Vet Intern Med 2005; 19: 515522.

    • Search Google Scholar
    • Export Citation
  • 9. Tanaka R, Murota A, Nagashima Y, et al. Changes in platelet life span in dogs with mitral valve regurgitation. J Vet Intern Med 2002; 16: 446451.

    • Search Google Scholar
    • Export Citation
  • 10. Olsen LH, Kristensen AT, Häggström J, et al. Increased platelet aggregation response in Cavalier King Charles Spaniels with mitral valve prolapse. J Vet Intern Med 2001; 15: 209216.

    • Search Google Scholar
    • Export Citation
  • 11. Cowan SM, Bartges JW, Gompf RE, et al. Giant platelet disorder in the Cavalier King Charles Spaniel. Exp Hematol 2004; 32: 344350.

    • Search Google Scholar
    • Export Citation
  • 12. Moesgaard SG, Sørensen TM, Sterup A, et al. Changes in platelet function in Dachshunds with early stages of myxomatous mitral valve disease. Res Vet Sci 2009; 86: 320324.

    • Search Google Scholar
    • Export Citation
  • 13. Nielsen LA, Zois NE, Pedersen HD, et al. Platelet function in dogs: breed differences and effect of acetylsalicylic acid administration. Vet Clin Pathol 2007; 36: 267273.

    • Search Google Scholar
    • Export Citation
  • 14. Moritz A, Walcheck BK, Weiss DJ. Evaluation of flow cytometric and automated methods for detection of activated platelets in dogs with inflammatory disease. Am J Vet Res 2005; 66: 325329.

    • Search Google Scholar
    • Export Citation
  • 15. Ahnadi CE, Boughrassa FF, Chapman-Montgomery ES, et al. Comparison of two methods to assess variability of platelet response to anti-platelet therapies in patients with acute coronary syndrome undergoing angioplasty. Thromb Haemost 2004; 92: 12071213.

    • Search Google Scholar
    • Export Citation
  • 16. Moritz A, Walcheck BK, Deye J, et al. Effects of short-term racing activity on platelet and neutrophil activation in dogs. Am J Vet Res 2003; 64: 855859.

    • Search Google Scholar
    • Export Citation
  • 17. Bauer NB, Er E, Moritz A. Effect of submaximal aerobic exercise on platelet function, platelet activation, and secondary and tertiary hemostasis in dogs. Am J Vet Res 2012; 73: 125133.

    • Search Google Scholar
    • Export Citation
  • 18. Smith JR, Smith KF, Brainard BM. Platelet parameters from an automated hematology analyzer in dogs with inflammatory clinical diseases. Vet J 2014; 201: 406411.

    • Search Google Scholar
    • Export Citation
  • 19. Macey MG, Carty E, Webb L, et al. Use of mean platelet component to measure platelet activation on the ADVIA 120 hematology system. Cytometry 1999; 38: 250255.

    • Search Google Scholar
    • Export Citation
  • 20. Smith FW, Keene BW, Tilley LP. Murmurs. In: Rapid interpretation of heart sounds, murmurs, and arrhythmias: a guide to cardiac auscultation in the dog and cat. 2nd ed. St Louis, Mo: Saunders Elsevier; 2006;3966.

    • Search Google Scholar
    • Export Citation
  • 21. Thomas WP, Gaber CE, Jacobs GJ, et al. Recommendations for standards in transthoracic two-dimensional echocardiography in the dog and cat. Echocardiography Committee of the Specialty of Cardiology, American College of Veterinary Internal Medicine. J Vet Intern Med 1993; 7: 247252.

    • Search Google Scholar
    • Export Citation
  • 22. Cornell CC, Kittleson MD, Della Torre P, et al. Allometric scaling of M-mode cardiac measurements in normal adult dogs. J Vet Intern Med 2004; 18: 311321.

    • Search Google Scholar
    • Export Citation
  • 23. Bertazzolo W, Comazzi S, Sesso L, et al. Comparison of methods for determining platelet numbers and volume in Cavalier King Charles Spaniels. J Small Anim Pract 2007; 48: 556561.

    • Search Google Scholar
    • Export Citation
  • 24. Clancey N, Burton S, Horney B, et al. Effects of in vitro hemodilution of canine blood on platelet function analysis using the PFA-100. Vet Clin Pathol 2009; 38: 467470.

    • Search Google Scholar
    • Export Citation
  • 25. Neter J, Wasserman W, Kutner MH. Multiple regression. In: Applied linear statistical models: regression, analysis of variance, and experimental designs. Homewood, Ill: R.D. Irwin; 1985;226270.

    • Search Google Scholar
    • Export Citation
  • 26. Barnett HJ, Jones MW, Boughner DR, et al. Cerebral ischemic events associated with prolapsing mitral valve. Arch Neurol 1976; 33: 777782.

    • Search Google Scholar
    • Export Citation
  • 27. Kostuk WJ, Boughner DR, Barnett HJ, et al. Strokes: a complication of mitral-leaflet prolapse? Lancet 1977; 2: 313316.

  • 28. Tse HF, Lau CP, Cheng G. Relation between mitral regurgitation and platelet activation. J Am Coll Cardiol 1997; 30: 18131818.

  • 29. Walsh PN, Kansu TA, Corbett JJ, et al. Platelets, thromboembolism and mitral valve prolapse. Circulation 1981; 63: 552559.

  • 30. Icli A, Aksoy F, Dogan A, et al. Mean platelet volume may be elevated in mitral valve prolapse and associated with the severity of prolapse. Clin Appl Thromb Hemost 2013; 19: 608612.

    • Search Google Scholar
    • Export Citation
  • 31. Varol E, Ozaydin M, Türker Y, et al. Mean platelet volume, an indicator of platelet activation, is increased in patients with mitral stenosis and sinus rhythm. Scand J Clin Lab Invest 2009; 69: 708712.

    • Search Google Scholar
    • Export Citation
  • 32. Koplitz SL, Scott MA, Cohn LA. Effects of platelet clumping on platelet concentrations measured by use of impedance or buffy coat analysis in dogs. J Am Vet Med Assoc 2001; 219: 15521556.

    • Search Google Scholar
    • Export Citation
  • 33. Davis B, Toivio-Kinnucan M, Schuller S, et al. Mutation in beta1-tubulin correlates with macrothrombocytopenia in Cavalier King Charles Spaniels. J Vet Intern Med 2008; 22: 540545.

    • Search Google Scholar
    • Export Citation
  • 34. Tsutsui H, Ishihara K, Cooper G 4th. Cytoskeletal role in the contractile dysfunction of hypertrophied myocardium. Science 1993; 260: 682687.

    • Search Google Scholar
    • Export Citation
  • 35. Koide M, Hamawaki M, Narishige T, et al. Microtubule depolymerization normalizes in vivo myocardial contractile function in dogs with pressure-overload left ventricular hypertrophy. Circulation 2000; 102: 10451052.

    • Search Google Scholar
    • Export Citation
  • 36. Briggs C, Harrison P, Machin SJ. Continuing developments with the automated platelet count. Int J Lab Hematol 2007; 29: 7791.

  • 37. Tvedten HW, Lilliehöök IE, Öberg J, et al. Validation of Advia plateletcrit for assessing platelet mass in dogs, including Cavalier King Charles Spaniels. Vet Clin Pathol 2012; 41: 336343.

    • Search Google Scholar
    • Export Citation
  • 38. McNiel EA, Ogilvie GK, Fettman MJ, et al. Platelet hyper-function in dogs with malignancies. J Vet Intern Med 1997; 11: 178182.

  • 39. Kribben A, Fritschka E, Sibold M, et al. Different effects of furosemide on alpha-adrenoceptors and on platelet aggregation in man. Klin Wochenschr 1988; 66: 624627.

    • Search Google Scholar
    • Export Citation
  • 40. Schäfer A, Fraccarollo D, Hildemann S, et al. Inhibition of platelet activation in congestive heart failure by aldosterone receptor antagonism and ACE inhibition. Thromb Haemost 2003; 89: 10241030.

    • Search Google Scholar
    • Export Citation
  • 41. Someya N, Morotomi Y, Kodama K, et al. Suppressive effect of captopril on platelet aggregation in essential hypertension. J Cardiovasc Pharmacol 1984; 6: 840843.

    • Search Google Scholar
    • Export Citation

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Platelet function and activation in Cavalier King Charles Spaniels with subclinical chronic valvular heart disease

Linda J. Tong BVSC1, Giselle L. Hosgood BVSC, PhD2, Anne T. French MVB, PhD3, Peter J. Irwin BVetMed, PhD4, and Robert E. Shiel MVB, PhD5
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  • 1 College of Veterinary Medicine, Murdoch University, Murdoch, WA, Australia 6150.
  • | 2 College of Veterinary Medicine, Murdoch University, Murdoch, WA, Australia 6150.
  • | 3 Department of Small Animal Clinical Sciences, School of Veterinary Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, Scotland G61 1QH.
  • | 4 College of Veterinary Medicine, Murdoch University, Murdoch, WA, Australia 6150.
  • | 5 College of Veterinary Medicine, Murdoch University, Murdoch, WA, Australia 6150.

Abstract

OBJECTIVE To assess platelet closure time (CT), mean platelet component (MPC) concentration, and platelet component distribution width (PCDW) in dogs with subclinical chronic valvular heart disease.

ANIMALS 89 Cavalier King Charles Spaniels (CKCSs) and 39 control dogs (not CKCSs).

PROCEDURES Platelet count, MPC concentration, PCDW, and Hct were measured by use of a hematology analyzer, and CT was measured by use of a platelet function analyzer. Murmur grade and echocardiographic variables (mitral valve regurgitant jet size relative to left atrial area, left atrial-to-aortic diameter ratio, and left ventricular internal dimensions) were recorded. Associations between explanatory variables (sex, age, murmur grade, echocardiographic variables, platelet count, and Hct) and outcomes (CT, MPC concentration, and PCDW) were examined by use of multivariate regression models.

RESULTS A model with 5 variables best explained variation in CT (R2, 0.74), with > 60% of the variance of CT explained by mitral valve regurgitant jet size. The model of best fit to explain variation in MPC concentration included only platelet count (R2, 0.24). The model of best fit to explain variation in PCDW included platelet count and sex (R2, 0.25).

CONCLUSIONS AND CLINICAL RELEVANCE In this study, a significant effect of mitral valve regurgitant jet size on CT was consistent with platelet dysfunction. However, platelet activation, as assessed on the basis of the MPC concentration and PCDW, was not a feature of subclinical chronic valvular heart disease in CKCSs.

Abstract

OBJECTIVE To assess platelet closure time (CT), mean platelet component (MPC) concentration, and platelet component distribution width (PCDW) in dogs with subclinical chronic valvular heart disease.

ANIMALS 89 Cavalier King Charles Spaniels (CKCSs) and 39 control dogs (not CKCSs).

PROCEDURES Platelet count, MPC concentration, PCDW, and Hct were measured by use of a hematology analyzer, and CT was measured by use of a platelet function analyzer. Murmur grade and echocardiographic variables (mitral valve regurgitant jet size relative to left atrial area, left atrial-to-aortic diameter ratio, and left ventricular internal dimensions) were recorded. Associations between explanatory variables (sex, age, murmur grade, echocardiographic variables, platelet count, and Hct) and outcomes (CT, MPC concentration, and PCDW) were examined by use of multivariate regression models.

RESULTS A model with 5 variables best explained variation in CT (R2, 0.74), with > 60% of the variance of CT explained by mitral valve regurgitant jet size. The model of best fit to explain variation in MPC concentration included only platelet count (R2, 0.24). The model of best fit to explain variation in PCDW included platelet count and sex (R2, 0.25).

CONCLUSIONS AND CLINICAL RELEVANCE In this study, a significant effect of mitral valve regurgitant jet size on CT was consistent with platelet dysfunction. However, platelet activation, as assessed on the basis of the MPC concentration and PCDW, was not a feature of subclinical chronic valvular heart disease in CKCSs.

Contributor Notes

Dr. Tong's present address is Western Australian Veterinary Emergency and Specialty, 1/640 Beeliar Dr, Success, WA, Australia 6164.

Dr. Shiel's present address is the School of Veterinary Medicine, University College Dublin, Belfìeld, Dublin 4, Ireland.

Address correspondence to Dr. Tong (lindajtong@gmail.com).