Relative prevalence of upper respiratory tract obstructive disorders in two breeds of harness racehorses (185 cases: 1998-2006).

The study compares the prevalence of upper respiratory tract (URT) disorders in two different breeds of Scandinavian harness racehorses: the Standardbred and the Coldblooded Trotter. The research found that these breeds present different predispositions to certain URT disorders due to their unique genetic and phenotypic characteristics.

Objective and Methodology

• This study aimed to compare the prevalence of upper respiratory tract disorders between two different breeds of harness racing horses: the Standardbred and the Coldblooded Trotter.
• The researchers performed a retrospective study of 88 Norwegian Coldblooded Trotters and 97 Standardbreds that were referred to a veterinary hospital for URT evaluation between 1998 and 2006.
• The records of all horses diagnosed with URT disorders were evaluated, as well as those who underwent high-speed treadmill videoendoscopy with one or more periods of induced poll flexion – a technique used to test for respiratory diseases in horses.
• The researchers then compared the prevalence of URT disorders between the two breeds using a statistical analysis tool called Fisher’s exact test.

Results of the Study

• The study found a significant predisposition against certain URT disorders in the two horse breeds. Specifically, bilateral dynamic laryngeal collapse associated with poll flexion and flaccid epiglottis were more common in Coldblooded Trotters.
• In contrast, conditions like alar fold collapse and nasopharyngeal collapse were more common in Standardbreds. Other disorders such as epiglottic entrapment and nasal flutter were only found in the Standardbreds.
• The results also revealed that dynamic disorders during physical activity were more prevalent than resting disorders in both horse breeds.

Conclusion and Recommendations

• The research concluded that the prevalence of URT blocking conditions such as laryngeal collapse, epiglottis issues, pharyngeal collapse, alar fold collapse, nasal flutter, and epiglottic entrapment are related to the breed of the horse. This suggests that these illnesses may be caused by anatomical or functional differences between the breeds.
• The researchers recommended a more in-depth anatomical or physiological study of these horse breeds. The findings of these studies could potentially provide more insight into the causes of certain URT disorders.
• They also proposed that induced poll flexion should be included as a routine measure in treadmill examinations of all harness racehorses to better detect URT disorders.