Transport-related respiratory pathogens in horses travelling long distances: A prospective study on arrival at the slaughterhouse.

This study investigates the incidence of respiratory disorders in horses resulting from long-distance travel, primarily during transport to slaughterhouses. The researchers analyze potential causes of these disorders, measure the presence of various disease-causing pathogens, and identify factors that could be contributing to increased susceptibility to these issues.

Methodology

The researchers studied a sample of 155 horses transported to two slaughterhouses located in Italy. Several methodologies were deployed over a 48-hour observation period post-arrival:

• The team obtained Deep Nasopharyngeal Swabs (DNS) from the horses to test for pathogens.
• A Polymerase Chain Reaction (PCR) test was used to quantify the presence of several potential disease-causing agents like influenza A virus, reovirus, multiple types of equine herpesvirus, adenovirus, rhinovirus, astrovirus, equine coronavirus, Pasteurellaceae, Streptococcus equi.
• Information regarding the horse’s journey, including departure point, stops en route, and other pertinent details, was also documented.
• The horses also underwent a welfare assessment to identify any signs of distress or compromised well-being.

Results

Pathogen prevalence varied across the sample:

• One horse showed positive test results for reovirus, and rhinovirus each and two horses for adenovirus.
• Streptococcus equi and zooepidemicus had a prevalence rate of 4% and 19%, respectively, while Pasteurellaceae was found in 63% of horses.
• Presence of Streptococcaceae and Pasteurellaceae was associated with physical symptoms such as sweating, abnormal demeanor, nasal or ocular discharge, and a general decline in welfare post-transport.

Data Analysis and Conclusions

A multivariable regression analysis indicated a connection between specific transport-related factors and the increased prevalence of certain pathogens:

• Horses departing from Eastern Europe or France were more likely to test positive for Streptococcaceae than those from Poland.
• Brief stops during travel were associated with higher Pasteurellaceae prevalence in broken horses.

The study concludes that these findings can contribute to a better understanding of factors predisposing horses to respiratory disorders during transport. This understanding is essential for developing regulations that protect the welfare of horses during transit.