Examination of hemostatic parameters to detect hypercoagulability in dogs with severe protein-losing nephropathy

Authors

  • Suzanne M. Donahue VMD, DACVECC,

    1. Department of Clinical Studies – Philadelphia, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104
    2. Veterinary Referral Center, 340 Lancaster Ave, Malvern, PA 19355 1804
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  • Marjory Brooks DVM, DACVIM,

    1. Comparative Coagulation Section, Animal Health Diagnostic Center, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853
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  • Cynthia M. Otto DVM, PhD, DACVECC

    1. Department of Clinical Studies – Philadelphia, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104
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  • Presented in part at 8th International Veterinary Emergency Critical Care Symposium September 2002, San Antonio, Texas.

  • Supported by VECCS Research Award.

  • The authors declare no conflict of interest.

Address correspondence and reprint requests to
Dr. Cynthia M. Otto, University of Pennsylvania, School of Veterinary Medicine, 3900 Delancey St, Philadelphia, PA 19104, USA. Email: cmotto@vet.upenn.edu

Abstract

Objective – To identify hemostatic abnormalities in dogs with protein-losing nephropathies (PLN) that represent risk factors for pathologic thrombosis.

Design – Cross-sectional observational study of client-owned dogs with PLN, nonprotein losing renal failure (RF), and systemic illness (SI) exclusive of primary renal disease.

Setting – Urban University Referral Center.

Animals – A total of 29 dogs (n=11 PLN, n=7 RF, n=11 SI) were enrolled between January 2001 and July 2002. Samples were also collected from 20 clinically normal dogs to serve as hemostasis assay controls.

Interventions – None.

Hemostasis Testing – Citrate anticoagulated blood was collected for point-of-care testing with a viscoelastic monitor (thromboelastograph [TEG]) and citrate plasma was prepared for coagulation screening tests and specific assay of the following hemostatic proteins: antiplasmin, antithrombin, D-dimer, Factor VIII, fibrinogen, plasminogen, protein C, and von Willebrand factor.

Results – Dogs with PLN and RF demonstrated TEG abnormalities consistent with hypercoagulability (eg, short clotting time, high clot amplitude) and both groups had significantly lower antithrombin than the SI group. The PLN dogs had significantly higher protein C than either the RF or SI group. Hyperfibrinogenemia was a consistent finding among all 3 disease groups, and the coagulation index a measure of hypercoagulability derived from TEG parameters, directly correlated with fibrinogen values of all study dogs.

Conclusions – Hemostatic abnormalities consistent with systemic hypercoagulability are common in dogs with RF and PLN, however, no prothrombotic factors unique to PLN were identified in our study. The thrombotic tendency of PLN may therefore involve parameters we did not directly assess such as platelet reactivity, fibrinolysis, perturbations in blood flow, and/or endothelial dysfunction. High protein C is a novel finding in PLN dogs of unknown clinical relevance.

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