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Thromboelastographic tracings in retired racing greyhounds and in non-greyhound dogs
P Vilar1, C G Couto, N Westendorf
1Department of Veterinary Clinical Sciences and Veterinary Teaching Hospital, The Ohio State University, Columbus, OH 43210, USA. vilarsaavedra.1@osu.edu
Insights
Greyhounds exhibit slower clotting kinetics and weaker clot strength compared to other dogs, explaining their increased bleeding risk. These differences in thromboelastography (TEG) parameters may relate to blood viscosity and sample citrate concentration.
Area of Science:
- Veterinary Medicine
- Hematology
- Canine Research
Background:
- Bleeding disorders are common in Greyhounds despite normal standard coagulation tests.
- Thromboelastography (TEG) is a valuable tool for assessing hemostasis.
Purpose of the Study:
- To compare TEG parameters between Greyhounds and non-Greyhound dogs.
- To investigate potential causes for bleeding tendencies in Greyhounds.
Main Methods:
- Healthy dogs, including 28 Greyhounds and 15 non-Greyhounds, were evaluated.
- Recalcified citrated native TEGs were performed on all dogs.
- Statistical analysis included Student's, Mann-Whitney, and Pearson's tests.
Main Results:
- Significant differences in TEG parameters were observed between Greyhounds and non-Greyhounds.
- Greyhounds showed a slower R-time and K-time, and a lower angle (alpha), maximum amplitude (MA), and clot strength (G).
- Exceptions included R-time and percent lysis at 60 minutes (LY60), which were not significantly different.
Conclusions:
- Greyhounds have inherently slower clotting kinetics and weaker clot strength than non-Greyhounds.
- These findings support the observed increased bleeding tendency in Greyhounds after minor procedures.
- Differences may be influenced by higher hematocrit and lower plasma volume in Greyhounds, affecting blood viscosity and citrate concentration.
Background:
Bleeding disorders in patients with normal coagulation test results are frequently reported in Greyhounds. The purpose of this study was to compare Greyhounds to non-Greyhounds by thromboelastography (TEG).
Hypothesis:
TEG parameters in Greyhounds are different from those in non-Greyhounds.
Animals:
Forty-three healthy dogs (28 Greyhounds and 15 non-Greyhounds) based on the results of physical examination, CBC, activated partial thromboplastin time, prothrombin time, fibrinogen, and platelet count.
Materials And Methods:
Recalcified citrated native TEGs were performed in both groups; data were compared using Student's, Mann-Whitney, and Pearson's statistical tests.
Results:
In Greyhounds, mean +/- SD were as follows: R-time 4.3 +/- 1.7 minutes, K-time 3.8 +/- 1.4 minutes, angle (alpha) 50.0 +/- 8.0 degrees , maximum amplitude (MA) 47.6 +/- 5.6 mm, clot strength (G) 4,647 +/- 1,097 dyn/cm2, and percent lysis at 60 minutes (LY60) 2.8 +/- 5.0%. In the non-Greyhounds they were R-time 3.7 +/- 1.6 minutes, K-time 2.5 +/- 0.9 minutes, angle 59.8 +/- 7.0 degrees , MA 53.1 +/- 5.6 mm, G 5,811 +/- 1,256 dyn/cm2, and LY60 3.1 +/- 2.5%. All parameters were significantly different between the groups, except for R-time and LY60.
Conclusion:
In Greyhounds, clotting kinetics are slower and clot strength are weaker than in non-Greyhounds, supporting the increased tendency to bleed observed after minor trauma or surgical procedures in the breed. The findings may also be attributed to blood viscosity or to the concentration of citrate in the sample (ie, Greyhounds have higher hematocrit and less plasma per unit volume).
