Research update: Transportation and health

Summarized by Devan Catalano, MS, University of Minnesota

Changes in the immune system and risk of respiratory disease in response to travel are well documented in horses. However, information on mucosal immune responses and how quickly changes occur is lacking. The goal of this research, conducted at the University of Florida, was to determine the onset of changes and the mucosal immune response to long distance road transportation.

Three cecally cannulated geldings were tied with their heads elevated and transported for 24 consecutive hours. Nasal flush (NPF), whole blood, cecal fluid, saliva and fecal samples were obtained before, during, immediately after, and five days after transportation.

Transportation resulted in bodyweight losses of 77 pounds despite access to hay and water while in transit, and was not regained by five days post transport. Neutrophils (a type of immune cell) were elevated from hour 6 of transit through 24 hours after transport and had returned to baseline by 72 hours post-transport. A decline in the number and percentage of white blood cells occurred during transport. However, white blood cells continued to increase five days post-transport. White blood cells in nasal flush samples had returned to baseline by 72 hours post transport. Both salivary and nasal flush samples had recovered to pre-transit values 72 hours post-transit. Fecal measurements of immune function were variable and lacked a clear pattern in response to transport.

Together these data indicate that transport can cause immune function changes. The consequences of these changes may be a predisposing factor for respiratory disease.