Diaphragmatic herniation as a cause of lethargy and exercise intolerance in a mare.

This research investigates a Quarter Horse mare diagnosed with a diaphragmatic hernia, which led to lethargy and exercise intolerance. The hernia occurred when 90% of the mare’s large colon passed through a tear in her diaphragm.

Background and Objective

• The study involves a 12-year-old Quarter Horse mare who was exhibiting clinical signs of lethargy and exercise intolerance.
• The primary objective of this research was to diagnose the cause of these symptoms and propose an adequate form of treatment. The researchers suspected a diaphragmatic hernia, a condition where organ(s) move from their usual position to the chest through a tear in the diaphragm, impairing respiratory and digestive functions.

Methods and Diagnosis

• The horse’s diagnosis involved a careful thoracic auscultation. This method is a clinical examination which involves listening to the sounds of the horse’s thorax using a stethoscope, aiming to detect any anomalies that could be causing the symptoms.
• This was combined with an ultrasonographic and radiographic examination of the thorax. These are imaging techniques that allow for a detailed view of the internal structures, which in this case, confirmed the presence of a diaphragmatic hernia.
• The examination revealed a significant herniation: 90% of the horse’s large colon had moved through a 16-cm linear tear in the diaphragm. Normally, the large colon is situated in the abdomen, and its displacement can cause a range of adverse symptoms.

Implications and Conclusion

• The discovery of this issue suggests that diaphragmatic hernias can be a cause of lethargy and exercise intolerance in horses.
• It highlights the importance of thorough examination techniques, including thoracic auscultation, ultrasonography, and radiography, in diagnosing internal injuries in animals.
• While the study does not elaborate on the treatment, identifying the problem allows veterinarians to pursue appropriate interventions and treatments such as surgical repair of the hernia, ultimately helping to improve the quality of life and performance of the animal.