Thirty of the 100 races planned for the evaluation have been acquired. Due to several logistic constraints and the measures to control the Covid-19 pandemic we seem not to be able to continue the study.
In a preliminary study there was examined the optimal time to collect the blood samples after racing for this study. The information is published in Veterinary Clinical Pathology.

Bos Astrid, Ellen Compagnie, Arno Lindner 2018 Effect of racing on blood variables in Standardbred horses. Veterinary Clinical Pathology; 1–4. 

Background: Blood is collected for hematologic and biochemical analyses when racehorses perform poorly. However, racing affects most analyte levels; therefore, the timing of blood sampling can affect analyte levels and interpretations.
Objective: This study aimed to determine if the blood variable levels returned to pre
racing levels 2 and 3 days postracing. 

Methods: Blood was sampled from 17 healthy racehorses pre and postracing. The variables measured from plasma were albumin, cholesterol, creatinine, calcium (Ca), phosphorus (P), magnesium (Mg), sodium (Na), potassium (K), creatine phosphokinase (CK), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), gammaglutamyl transferase (GGT), and cortisol. Hematocrit (HCT), hemoglobin (HGB), white blood cell (WBC), red blood cell (RBC), granulocyte, and lymphocyte counts were analyzed from blood collected in EDTAcoated vials. 

Results: Calcium was lower 3 days postracing compared with 2 days preracing (P < 0.01), P and GGT were higher 2 and 3 days postracing compared with those at the preracing timepoints (P ≤ 0.01), and RBC, HCT, and HGB were higher 2 days postracing compared with those at the preracing and 3day postracing time points (P < 0.01, all). 

Conclusions: A few blood biochemical and hematologic variables were significantly altered 2 and 3 days postracing. The level of these changes did not affect the clinicopathologic interpretation of the values. 


Astrid Bos, Arno Lindner


Since 2014 and ongoing


The values of blood variables of Standardbreds with poor performance (loosers) differ from those with good performance (winners).

Material and methods
  • The blood of Standardbred racehorses that raced will be sampled in the morning (7.00 to 9:00 hours) 2 (3) days after racing before exercising.
  • The horses of interest are the winner, horses placed (2-4 placed) and the loosers (placed after the 5th) of at least 50, better 100 races.
  • Five ml of blood samples are taken by puncture of the jugular vein and collected in a vial with Li-heparin and another with EDTA.
  • Samples are placed in a cooling box with ice pads in it and a towel on top / or a newspaper = a separating layer between the ice and the blood vials. On top of the separating layer the stand with the upright blood vials will be positioned such that it cannot move. The temperature should not be above 10°C and not below 2°C. Blood samples will be taken to the clinic where the haematological analysis is done (haematocrit, hemoglobin, total white blood cells, number of erythrocytes, granulocytes and lymphocytes).
  • The rest of the samples will be centrifuged, plasma separated and frozen at -20°C (or more) until analysis.
  • Plasma variables to be measured are: GGT, Albumin, Cholesterol, Creatinine, Ca, P, Mg, Na, K, CK, AST, LDH and Cortisol.
Further parameters recorded
  1. Body condition score and body weight of horses before and after racing.
  2. Amount of kilometres or duration of transport after racing
  3. Race day and number, horse name, horse number and placing as well as age and gender and winning sum (or race record).
Partial funding