Exercise-Associated Sudden Death in Finnish Standardbred and Coldblooded Trotters - A Case Series With Pedigree Analysis.
Authors: Trachsel Dagmar S, Calloe Kirstine, Mykkänen Anna K, Raistakka Pia, Anttila Marjukka, Fredholm Merete, Tala Martti, Lamminpää Katariina, Klaerke Dan A, Buhl Rikke
Journal: Journal of equine veterinary science
Summary
# Exercise-Associated Sudden Death in Finnish Standardbred and Coldblooded Trotters: What the Evidence Shows Between 2002 and 2017, Finnish researchers investigated 50 racehorses with exercise-associated sudden death (EASD), comparing their pedigree data and racing performance against control groups of horses with musculoskeletal injuries and unaffected contemporaries, using necropsy reports to distinguish between sudden cardiac death, arrhythmia-related cases, and other causes. Although genetic variants causing cardiac arrhythmias are implicated in sudden cardiac death in humans and could theoretically increase in frequency through inbreeding, the study found no significant differences in inbreeding coefficients or career earnings between horses that died suddenly and either the injury-control group or the general racing population. The 25 cases of possible cardiac arrhythmia and 2 confirmed cardiac diseases could not be linked to familial genetic clustering, suggesting that—at least in this Scandinavian population—exercise-related sudden cardiac events are not predominantly driven by heritable arrhythmia variants concentrated through selective breeding. For equine professionals managing racehorses, particularly trotters, this finding implies that sudden cardiac death risk cannot currently be predicted or managed through pedigree screening alone, and that alternative approaches to risk assessment during training and competition require investigation.
Read the full abstract on PubMed
Practical Takeaways
- •Sudden cardiac death accounts for a notable proportion of unexplained exercise-associated deaths in racing trotters, but genetic predisposition linked to inbreeding cannot be confirmed as a risk factor in this population
- •Veterinarians investigating sudden death in racehorses should pursue thorough necropsy examination to differentiate between cardiac causes, vessel rupture, and other fatal conditions, as diagnosis impacts breeding and training decisions
- •Pedigree screening based on inbreeding coefficients alone is not justified as a preventive strategy for SCD in these horse populations based on current evidence
Key Findings
- •Of 61 horses that died during the study period (2002-2017), 25 cases had possible cardiac arrhythmia as cause, 2 had identified cardiac disease, and 7 died from major vessel rupture
- •No significant differences in inbreeding coefficients were found between horses with SCD and control groups (either musculoskeletal injury deaths or healthy racing horses)
- •No significant differences in career earnings were found between horses with EASD and control horses racing during the same period
- •The study provides no evidence supporting the hypothesis that increased inbreeding is associated with SCD in Finnish Standardbred and Coldblooded trotters