Aortic rupture and aorto-pulmonary fistulation in the Friesian horse: characterisation of the clinical and gross post mortem findings in 24 cases.

This study examines the medical conditions of aortic rupture and aorto-pulmonary fistulation in Friesian horses using clinical data and post-mortem analysis from 24 cases over a 13-year period. It provides valuable insights into the prevalence, symptomatology and mortality of these conditions and emphasizes the need for equine practitioners to consider these when examining Friesian horses presenting with certain symptoms.

Study Overview and Methodology

In this research, the authors concentrated on two related medical conditions found in Friesian horses: aortic rupture and aorto-pulmonary fistulation. Over a period of 13 years, from 1997 to 2010, the researchers collected data from 24 diagnosed cases at Utrecht University’s Department of Equine Sciences and Wolvega Equine Hospital. They closely examined:

• Patient history.
• Clinical examination results.
• Gross post-mortem findings.

Results and Findings

The study highlighted a range of findings:

• Some horses were found dead with no prior symptoms, however, others displayed signs such as recurring colic, peripheral swelling (oedema), and persistent fast heart rate (tachycardia) before succumbing to cardiac failure.
• Clinical examination during hospitalisation often revealed increased rectal temperature, peripheral oedema and increased jugular pulse with a bounding arterial pulse.
• In most cases, post-mortem examinations revealed an aortic rupture located at the aortic arch near the arteriosum ligamentum, a band of perivascular hemorrhage, and aorto-pulmonary fistulation.

Conclusions and Implications

The conclusions drawn from this study have significant implications for practitioners. It was determined that:

• Aorto-pulmonary fistulation occurring in conjunction with aortic rupture is more common in Friesian horses than previously estimated. Therefore, it is essential to consider these conditions when assessing their health.
• In some cases, there appears to be a progression of the disease rather than it causing sudden cardiac failure and death. This emphasizes the need for careful and ongoing observation of horses that might be at risk.
• During post-mortem examinations, it is important not to miss these conditions, requiring a suitably detailed and meticulous approach.
• Equine practitioners should consider a possible aortic rupture or aorto-pulmonary fistulation in Friesian horses presenting with recurring false colic, coughing, persistent tachycardia and/or peripheral oedema.