Vet Med - Czech, 2026, 71(6):245-253 | DOI: 10.17221/4/2026-VETMED

A reproducible rat model for warfarin studies: Prothrombin time assessment with minimal blood using the CoaguChek XS and determination of an effective warfarin dosageOriginal Paper

ET Akyol ORCID...1, MT Hekim ORCID...2, M Erol ORCID...1
1 Department of Surgery, Faculty of Veterinary Medicine, Balikesir University, Balikesir, Türkiye
2 Department of Cardiology, Faculty of Medical Science, Balikesir University, Balikesir, Türkiye

Warfarin research in rats is often challenged by methodological inconsistencies and large blood volume requirements. This study aimed to validate a refined, reproducible rat model for serial prothrombin time (PT) monitoring using the CoaguChek XS, in alignment with the 3R principles, and to determine an effective warfarin sodium dosage. Male Wistar albino rats received daily oral warfarin (0.125–0.750 mg/kg) for 5 days. PT was measured using the whole-blood CoaguChek XS and two laboratory plasma assays (Innovin, Thromborel S). Agreement was assessed using Bland–Altman and Passing–Bablok regression. The CoaguChek XS consistently yielded higher PT values than laboratory tests but showed strong agreement up to 25 seconds. A daily dose of 0.125 mg/kg resulted in a stable anticoagulant effect without mortality. Doses Doses of 0.250 mg/kg and higher were toxic, causing PT prolongation beyond the device’s range and high mortality within 4–7 days after the initiation of treatment. In conclusion, the CoaguChek XS is a reliable tool for experiments requiring repeated measurements. Values remain reliable up to 25 s, and 0.125 mg/kg is a safe dose for short-term studies, effectively supporting animal welfare and the 3R principles.

Keywords: anticoagulation; haemostasis; gavage; thromboplastin; welfare

Received: January 14, 2026; Revised: April 9, 2026; Accepted: April 9, 2026; Prepublished online: June 25, 2026; Published: June 29, 2026  Show citation

ACS AIP APA ASA Harvard Chicago Chicago Notes IEEE ISO690 MLA NLM Turabian Vancouver
Akyol E, Hekim M, Erol M. A reproducible rat model for warfarin studies: Prothrombin time assessment with minimal blood using the CoaguChek XS and determination of an effective warfarin dosage. Veterinární medicína. 2026;71(6):245-253. doi: 10.17221/4/2026-VETMED.
Share...
Download citation
  • BibTeX (.bib)
  • Bookends (.ris)
  • EasyBib (.ris)
  • EndNote (.enw)
  • EndNote 8 (.xml)
  • ISI WoS (.isi)
  • Medlars (.medlars)
  • Mendeley (.ris)
  • MODS (.xml)
  • Papers (.ris)
  • RefWorks (.txt)
  • RefManager (.ris)
  • RIS (.ris)
  • MS Word (.xml)
  • Zotero (.ris)
    • Open full article

    References

    1. Alnaqeeb M, Mansor KA, Mallah EM, Ghanim BY, Idkaidek N, Qinna NA. Critical pharmacokinetic and pharmacodynamic drug-herb interactions in rats between warfarin and pomegranate peel or guava leaves extracts. BMC Complement Altern Med. 2019 Jan 24;19(1):29. Go to original source...
    2. Arifin WN, Zahiruddin WM. Sample size calculation in animal studies using resource equation approach. Malays J Med Sci. 2017 Oct;24(5):101-5. Go to original source... Go to PubMed...
    3. Asberg A, Hegseth H, Averina M, Lofblad L. The individual systematic difference between CoaguChek and STA-SPA. Scand J Clin Lab Invest. 2019 May;79(3):143-7. Go to original source...
    4. Baccouche H, Chakroun A, Zoghlami A, Mahjoub S, Ben Romdhane N. The international normalized ratio (INR): What reagent, what instrument? The assessment of the agreement between INR values according to different reagent/instrument combinations. J Clin Pharm Ther. 2018 Feb;43(1):52-8. Go to original source...
    5. Baker WS, Albright KJ, Berman M, Spratt H, Mann PA, Unabia J, Petersen JR. POCT PT INR - Is it adequate for patient care? A comparison of the Roche Coaguchek XS vs Stago Star vs Siemens BCS in patients routinely seen in an anticoagulation clinic. Clin Chim Acta. 2017 Sep;472:139-45. Go to original source... Go to PubMed...
    6. Biedermann JS, Leebeek FW, Buhre PN, de Lathouder S, Barends JP, de Maat MP, van der Meer FJ, Kruip MJ. Agreement between Coaguchek XS and STA-R Evolution (Hepato Quick) INR results depends on the level of INR. Thromb Res. 2015 Sep;136(3):652-7. Go to original source... Go to PubMed...
    7. Fitzmaurice DA, Gardiner C, Kitchen S, Mackie I, Murray ET, Machin SJ; British Society of Haematology Taskforce for Haemostasis and Thrombosis. An evidence-based review and guidelines for patient self-testing and management of oral anticoagulation. Br J Haematol. 2005 Oct;131(2):156-65. Erratum in: Br J Haematol. 2006 Jan;132(1):118. Go to original source... Go to PubMed...
    8. Fonseca MES, Balbi GGM, Signorelli F, Gouvea CP, de Andrade DCO. CoaguChek® XS versus standard laboratory prothrombin time for anticoagulant monitoring in patients with antiphospholipid syndrome. Lupus. 2022 Apr;31(5):565-74. Erratum in: Lupus. 2022 Apr;31(5):646. Go to original source...
    9. Garcia-Manzano A, Gonzalez-Llaven J, Lemini C, Rubio-Poo C. Standardization of rat blood clotting tests with reagents used for humans. Proc West Pharmacol Soc. 2001;44:153-5.
    10. Harikrishnan VS, Hansen AK, Abelson KS, Sorensen DB. A comparison of various methods of blood sampling in mice and rats: Effects on animal welfare. Lab Anim. 2018 Jun;52(3):253-64. Go to original source...
    11. Hirsh J, Fuster V, Ansell J, Halperin JL; American Heart Association; American College of Cardiology Foundation. American Heart Association/American College of Cardiology Foundation guide to warfarin therapy. Circulation. 2003 Apr 1;107(12):1692-711. Go to original source... Go to PubMed...
    12. John J, John M, Wu L, Hsiao C, Abobo CV, Liang D. Effects of etravirine on the pharmacokinetics and pharmacodynamics of warfarin in rats. Br J Pharmacol. 2013 Apr;168(8):1851-8. Go to original source... Go to PubMed...
    13. Krouwer JS, Monti KL. A simple, graphical method to evaluate laboratory assays. Eur J Clin Chem Clin Biochem. 1995 Aug;33(8):525-7.
    14. Levy JH, Szlam F, Wolberg AS, Winkler A. Clinical use of the activated partial thromboplastin time and prothrombin time for screening: A review of the literature and current guidelines for testing. Clin Lab Med. 2014 Sep;34(3):453-77. Go to original source...
    15. Mahaboob S, Ganesh GNK, Arun KP, Rajendran SD. Various factors influencing the enantiomers of warfarin pharmacokinetics: A systematic review of population pharmacokinetics. J Pharmacol Pharmacother. 2023 Sep; 14(3):178-86. Go to original source...
    16. Mischke R. Prothrombin time standardisation in canine samples with regard to inter-batch and inter-reagent variability. Vet J. 2011 Jun;188(3):301-6. Go to original source... Go to PubMed...
    17. Nahas K, Provost JP. Blood sampling in the rat: Current practices and limitations. Comp Clin Pathol. 2002 Jan;11(1):14-37. Go to original source...
    18. Parasuraman S, Raveendran R, Kesavan R. Blood sample collection in small laboratory animals. J Pharmacol Pharmacother. 2010 Jul;1(2):87-93. Erratum in: J Pharmacol Pharmacother. 2017 Jul-Sep;8(3):153. Go to original source... Go to PubMed...
    19. Plesch W, Wolf T, Breitenbeck N, Dikkeschei LD, Cervero A, Perez PL, van den Besselaar AM. Results of the performance verification of the CoaguChek XS system. Thromb Res. 2008;123(2):381-9. Go to original source... Go to PubMed...
    20. Rababa'h AM, Al Yacoub ON, El-Elimat T, Rabab'ah M, Altarabsheh S, Deo S, Al-Azayzih A, Zayed A, Alazzam S, Alzoubi KH. The effect of hawthorn flower and leaf extract (Crataegus spp.) on cardiac hemostasis and oxidative parameters in Sprague Dawley rats. Heliyon. 2020 Aug 22;6(8):e04617. Go to original source...
    21. Salemink PJM, Korsten J, de Leeuw P. Prothrombin times and activated partial thromboplastin times in toxicology: A comparison of different blood withdrawal sites for Wistar rats. Comp Haematol Int. 1994 Sep;4(3):173-6. Go to original source...
    22. Tan CSS, Lee SWH. Warfarin and food, herbal or dietary supplement interactions: A systematic review. Br J Clin Pharmacol. 2021 Feb;87(2):352-74. Go to original source...
    23. Westgard JO, Westgard SA. The quality of laboratory testing today: An assessment of sigma metrics for analytic quality using performance data from proficiency testing surveys and the CLIA criteria for acceptable performance. Am J Clin Pathol. 2006 Mar;125(3):343-54. Go to original source...
    24. Zeiler GE, Dzikiti BT, Rioja E, Kamerman P, Buck RK, Pohlin F, Fuller A. Prothrombin and activated partial thromboplastin times, thromboelastography, hematocrit, and platelet count in a feline hemorrhage/over-resuscitation model using lactated Ringer's solution or 6% tetrastarch 130/0.4. J Vet Emerg Crit Care (San Antonio). 2024 Jul-Aug;34(4):356-67. Go to original source... Go to PubMed...

    This is an open access article distributed under the terms of the Attribution 4.0 International (CC BY 4.0.), which permits use, distribution, and reproduction in any medium, provided the original publication is properly cited. No use, distribution or reproduction is permitted which does not comply with these terms.


    Return to the content