To determine the reasonable direction for loading horses during transportation, we loaded 12 yearling Thoroughbred horses in pairs into a horse-carrying vehicle, and without tethering them, drove with either minimal acceleration and deceleration (normal travel group) or repeated sudden stops (abrupt stop travel group). As we investigated how these horses behaved and postured inside the vehicle throughout repeating trials, we observed the following: 1) While the vehicle was on the road, the horses exhibited significantly less feeding behavior (P<0.01) and significantly more standing (P<0.01) than while the vehicle was parked. 2) In the normal travel group, the frequency with which the horses changed direction inside the vehicle decreased significantly (P<0.01) with repeated trials. Moreover, the horses' behavior of facing away from the direction of travel increased significantly (P<0.01). 3) In the abrupt stop travel group, the number of direction changes made by the horses inside the vehicle did not decrease, and no tendency was observed in the direction the horses preferred to face during the repeated trials. Consequently, it was suggested that transporting restrained horses with their heads facing backward is a rational way.
For a light microscopic examination from a large amount of horse hoof specimen, we usually apply a grinding technique using a hydrophobic resin to prepare a thin ground section. After preparation of the resin-embedded thin ground section (RGS), we stain it without prior deresinization or heating in any stages of the staining procedures in order to intensify the stain outcome. This technique includes an advantage to prevent RGS from modification. We do not study, however, the stain characteristics of the RGSs of the hoof tissues which are made by the above procedures. Therefore, we compared the RGSs (n=11) with the standard paraffin-embedded sections (PSs) (n=11) with H.E. stain, Ayoub-Shklar method and Dane's method. The H.E. stained RGS did not essentially differ from the one of the PS, but two special stain methods showed different stain characteristics compared with the stain outcome of the PS. From these results, H.E. stain is an applicable stain technique for the non-deresinized thin ground sections of the horse hooves.
A bicompartment model has been proposed to describe the distribution of lactate between the active space—muscles—and passive space —plasma and red blood cells—. This transport could be conditioned by the possible existence of a membrane-carrier, blood pH, the concentration of several hormones, the haematocrit value and the haemoglobin concentration. The purpose of this study was to determine the influence exercised by some haematological parameters in the lactate transport between plasma and red blood cells. Twelve male 4-year-old Andalusian horses were subjected to an exercise test, composed of 5 bouts at 4, 5, 6, 7 and 8 m/s, over a distance of 1, 000 m at each level. The horses were given a 3 min. rest between each bout. Venous blood samples were collected at rest, on finishing each level of exercise and at 6, 10, 15 and 30 min of an active recuperation. In blood, pH, RBC, PCV, Hb, MCV, MCH and MCHC were determined. Lactate concentrations were analyzed in plasma and hemolysed blood. Other indices, such as VLA4 (Velocity at a lactate concentration of 4 mmol/l), Rtd (Rate of lactate disappearance) and ΔLA (Increase in lactate concentrations) were calculated. The highest lactate concentrations were found inside the erythrocytes. The lower values corresponded to plasma, whilst the mean concentrations were observed in hemolysed blood. These differences were only significant at rest and at the two initial levels of exercise. As a consequence, there were found significant differences between VLA4, Rtd and ΔLA determined in the three media. A positive correlation between blood lactate, PCV, Hb and RBC and a negative correlation to pH were observed. Plasma and erythrocyte lactate showed a negative correlation to pH. Finally, intraerythrocyte lactate was positively correlated to MCH and MCHC.
We examined nerve growth factor (NGF) activity in sera obtained from 5 Anglo-Arab and 6 Thoroughbred horses after long-distance truck transportation. NGF activity was evaluated by neurite outgrowth from rat pheochromocytoma cells that respond to NGF. Five of 11 horses had mild or severe fever after the truck shipping; significant NGF activity was detected in serum samples collected from 4 of the fevered horses. The addition of polyclonal antibodies to murine 2.5S NGF completely abrogated the neurotrophic activity detected in the samples. These results suggested a possible role of NGF in the pathogenesis of equine shipping fever associated with continuous stress by truck transportation.
We used sevoflurane for inhalation anesthesia for internal fixation of a fracture of the tibia in a 3-year-old Thoroughbred race horse. The stage of surgical anesthesia was maintained by an end-tidal sevoflurane concentration of 2.6-2.9%. The anesthesia time was 7 hr, and the time from extubation until standing was 2 hr in this case. No marked problems on pulmonary and cardiovascular function have been observed during surgery in this case. The postoperative creatinine phosphokinase and lactate dehydrogenase levels were markedly high (17, 280 and 5, 080 U/l, respectively), and induration swelling was observed in the musculus longissimus of the back and the mesogluteus. These findings suggest myopathy. However, no marked post-anesthetic problems such as difficulty in standing developed. Sevoflurane seems to be a safe anesthetic for long term inhalation anesthesia in horses. The maintenance concentration of sevoflurane seen in this horse clinically supported the estimated concentration based on the minimum alveolar concentration of sevoflurane.