Exercise-Associated Sudden Death in Finnish Standardbred and Coldblooded Trotters – A Case Series With Pedigree Analysis.

The study examined if there was a genetic link to sudden death during or shortly after exercise in Finnish Standardbred and Coldblooded Trotters between 2002 and 2017. However, it found no significant differences in inbreeding coefficients or career earnings amongst horses diagnosed with sudden cardiac death (SCD).

Understanding the Research

• The research revolves around Exercise-associated sudden deaths (EASDs), specifically sudden cardiac death (SCD), which is a serious issue in animals, especially racehorses. These deaths can occur unexpectedly during or immediately after strenuous exercise.
• The study proposes that SCD could be caused by cardiac arrhythmias triggered by genetic variants, akin to similar cases in humans. Genetic variants are known to be inheritable, and their likelihood can increase with a higher inbreeding factor.
• The hypothesis inherently suggests that greater instances of inbreeding could potentially be decreasing race performance and increasing the risk of fatal sudden cardiac events.

Methodology

• A comparative analysis was performed over data sourced from horses diagnosed with SCD during 2002 and 2017. The study groups consisted of horses that had encountered catastrophic musculoskeletal injuries, and those that had participated in racing events during the same period without any reported health problems.
• The SCD diagnosis was based on necropsy reports, which included both macroscopic and microscopic examinations of the deceased horses.
• A total of 61 horse deaths were recorded for research, and 11 were excluded due to incomplete autopsy reports. After thorough investigation, 25 cases were attributed to an unknown cause, potentially cardiac arrhythmia. In contrast, 2 cases were confirmed as cardiac disease, 7 cases were due to a major vessel rupture, and 16 horses had either died or been euthanized due to severe musculoskeletal injuries.

Findings of the Study

• The study found no significant differences in inbreeding coefficients or career earnings among the horse groups analyzed.
• Thus, it concluded that there was no evidence supporting increased inbreeding factor or its relation to SCD in Finnish racehorses during the 15-year observation period.