Physiological responses of horses to 24 hours of transportation using a commercial van during summer conditions.

Abstract

Fifteen mature horses (mares, n = 6); geldings, n = 9) were used to assess the physiological responses of 24 h of transport in a commercial van under California summer conditions. The study was conducted on four consecutive days, and data were collected on d 1 and d 2 to obtain baseline values and to determine any diurnal variation in the individual measurements. Travel commenced on d 3 at 0800 for 24 h, with a total of 1,622 km traveled. Blood samples were collected at 0800, 1100, 1400, 2000, and 0200 each day. Horses were weighed and rectal temperatures recorded at 0800 each day and at 2000 each day except d 3. Body weight, rectal temperature, serum cortisol, serum lactate, and white blood cell (WBC) counts exhibited diurnal variation (P = .0001) on d 1 and d 2. Body weight immediately after unloading showed a 6% loss. At 24 h following transit, a 3% deficiency in body weight loss remained. The WBC counts showed a progressive increase with duration of travel and peaked at the termination of transport. Dehydration measures of hematocrit and total protein increased during transport and returned to baseline during the posttransport period. Serum concentrations of lactate, creatine kinase and aspartate aminotransferase increased during transport and in the early posttransit period, but returned to baseline values at the conclusion of the 24-h posttransport period. Glucose concentration increased with the initiation of transport and did not decrease to baseline concentration at the end of the 24-h posttransport period. Plasma cortisol and neutrophil:lymphocyte ratio increased with duration of transit and returned to baseline during the posttransport period. These data clearly showed physiological responses of horses undergoing 24 h of transport including changes in muscle metabolism, stress indices, dehydration and immune parameters, and body weight. These responses may increase disease susceptibility and influence energy availability for athletic performance following long-term transport of horses.

Physiological variables of horses after road transport

“…The physiologic responses of horses to short road transport show a decrease in BW (although not significant), as confirmed by a negative correlation only between BW and T 3 , as well as an increase in rectal temperature, in accordance with that reported after long, medium and short trips (Waran et al, 1996;Stull, 1999;Stull and Rodiek, 2000). However, no differences were observed relating to different ages.…”

Relationship between Transportation Stress and Polymorphonuclear Cell Functions of Bottlenose Dolphins, Tursiops truncatus

“…We did not evaluate the changes of cortisol, leukograms, and PMN cell functions after transportation. In terrestrial mammals, these parameters are recovered to a level before transportation within a week at most [15,22,27]. These reports showed that immunological uncertainty followeding transportation would enhance the potential risk of infectious disease in susceptible individuals.…”

“…The observed changes in phagocytosis and NBT reduction were correlated with alterations in circulating concentrations of cortisol induced by the stress of handling and transportation. Elevated serum cortisol concentrastions and changes in immune systems have been reported associated with the transportation of terrestrial mammals [22,27,30]. There are few reports on the effects of stress on PMN cell functions, however, Dixit et al [7] reported that stress was correlated with neutrophil functions.…”

“…Studies on other species have demonstrated that such responses are associated with impaired host defenses and thus many predispose to disease [13,15,17,27]. Stress is defined as the response of the body to any threatening situation, and a resource-based trade-off between the immune system and costly behavior characterizesd by stress-induced immunosuppression [23].…”

Effects of transportation procedures on salivary and plasma cortisol concentrations in cold-blood horses

“…Transit from 50 to 500 km significantly changed the cortisol release ratio, however, it did not influence plasma or salivary cortisol levels determined immediately after unloading (Fazio et al 2008, Schmidt et al 2010c. A 24 hour resting period after 24 hours of transport was generally sufficient to restore the plasma cortisol concentration to initial levels, even on a summer day, with maximal environmental temperature exceeding 38°C (Fazio et al 2008b, Stull et al 2008, Stull and Rodiek 2000. Moreover, Schmidt et al (2010a,b,c) stated that salivary cortisol concentration in experienced horses decreased after transport to baseline values within 30 min, and in naïve horses, within three hours.…”