Retrospective evaluation of episodic collapse in the horse in a referred population: 25 cases (1995-2009).

This research article investigates the causes and outcomes of episodic collapse, a condition of sudden loss of posture and/or consciousness, in horses using a retrospective study of 25 cases referred from the Dick Vet Equine Hospital, University of Edinburgh between 1995 and 2009.

Research Objective and Methodology

• The study aimed to understand the causes and outcomes of episodic collapse in horses, a condition which has clear implications for equine welfare and human safety. The lack of published series describing this syndrome highlights the importance of this study.
• The researchers used a retrospective study design, analyzing case records from the Dick Vet Equine Hospital located at the University of Edinburgh. The selection period spanned from November 1995 to July 2009.
• The cases were specifically sourced using keywords: collapse, collapsing, fall, syncope, to identify instances where a horse experienced a loss of postural tone, and possibly also lost consciousness and fell.
• Long-term follow-up information, crucial to understanding the durability and effectiveness of treatments, was obtained through telephone discussions with the owners of the horses.

Results

• Out of the 25 horses studied, a final diagnosis was reached in 11 cases. The causes included cardiac arrhythmia, right-sided heart failure, hypoglycemia, generalized seizures, and sleep disorder.
• A presumptive diagnosis, where the potential cause was identified but not definite, was reached in 8 cases. These included neurocardiogenic syncope, exercise-induced pulmonary hemorrhage, and generalized seizures.
• No diagnosis was reached in 6 cases, indicating the complexity of identifying the cause of episodic collapse in horses.
• Three horses were euthanized at presentation, showcasing the severe implications of untreated or undiagnosed episodic collapses.
• The treatment was attempted in 9 horses, 6 of which were successful before they were discharged from the hospital.
• A follow-up survey of 14 out of 19 horses that were discharged from the hospital showed only 1 horse having a repeated collapse event post-discharge.

Conclusions

• The study found that a definitive diagnosis was more likely to be reached in cases with multiple collapse episodes, indicating that recurrence might aid in better understanding the condition and its causes.
• Interestingly, horses experiencing one collapse episode did not necessarily collapse again, suggesting that single instances of collapse might not indicate a chronic condition.