Blood gas tensions, acid-base status, heart rates, and venous profiles in exercising horses with laryngeal hemiplegia before and after corrective surgery.

This research article examines the effects of exercise in horses suffering from complete laryngeal hemiplegia before and after treatment with a laryngeal prosthesis and ventriculectomy. It presents findings that indicate surgery improved the horses’ condition, but not to the level of normal horses.

Objective and Methods of the Study

• The research aimed to investigate the physiological impact of exercise in four horses living with complete laryngeal hemiplegia, a condition that disrupts normal breathing in horses resulting in poor performances and exercise intolerance.
• To study this, the researchers elevated the horses’ right carotid arteries to a subcutaneous position surgically for percutaneous catheterization. This process facilitated the collection of blood samples.
• Each horse was outfitted with a device to collect multiple arterial samples while running a course spanning 1.6-km.
• The test, including ten gallops and multiple sample collections, was conducted before and after treating the subjects with a laryngeal protheses and ventriculectomy to counter laryngeal hemiplegia.

Results of the study

• The results showed that horses afflicted with laryngeal hemiplegia experienced problems associated with acidosis, hypoxia, and hypercapnia compared to healthy horses. Acidosis refers to a high level of acid in the body, hypoxia is a lack of sufficient oxygen, and hypercapnia refers to a buildup of CO2 in the bloodstream.
• The surgical treatment – the application of a laryngeal prosthesis and ventriculectomy – resulted in a significant improvement in the horses’ blood gas and acid-base status. This treatment, therefore, could alleviate some of the symptoms resulting from the disease.
• However, despite the improvement, the values were not at par with those in healthy horses who had been subjected to similar tests.

Conclusions

• The study conclusively demonstrates the detrimental effects of laryngeal hemiplegia on exercising horses, causing acidosis, hypoxia, and hypercapnia.
• It also suggests that surgical intervention using laryngeal prosthesis and ventriculectomy can improve the physiological response and tolerance to exercise in horses with laryngeal hemiplegia, though not to the level of healthy horses.