The effects of probiotics on horses are still controversial. The present study was a randomized, double-blinded, placebo-controlled crossover study designed to evaluate the ability of probiotics to improve intestinal conditions in adult horses. Fermented probiotics were administered to 10 healthy adult geldings for 28 days. The clinical condition of the horses was monitored daily, and the blood and feces were biochemically analyzed every 14 days. In the probiotic-treated group, the concentration of carboxylic acids in the feces was increased at days 14 and 28. In contrast to the fecal pH in the control group, which increased at days 14 and 28, the fecal pH in the probiotic-treated group did not increase. Additionally, the relative amounts of enteropathogenic bacterial DNA were diminished in the probiotic-treated group. These results suggest that probiotic bacteria proliferated in the equine intestine. No instances of abnormal clinical conditions or abnormal values in blood tests were observed throughout the study. Oral administration of fermented probiotics may have the ability to improve the intestinal environment biochemically and microbiologically without the risk of adverse effects.

View full abstract

It is important to know the effects of the inclination of a slope on the activity of each muscle, because training by running on a sloped track is commonly used for Thoroughbred racehorses. The effects of incline (from −6 to +6%) on the forelimbs and hind limbs during walking and trotting on a treadmill were evaluated by an integrated electromyogram (iEMG). The muscle activities in the forelimbs (5 horses) and hind limbs (4 horses) were measured separately. Two stainless steel wires were inserted into each of the brachiocephalicus (Bc), biceps brachii (BB), splenius (Sp), and pectoralis descendens (PD) in the forelimb experiment and into the longissimus dorsi (LD), vastus lateralis (VL), gluteus medius (GM), and biceps femoris (BF) in the hind limb experiment. The EMG recordings were taken at a sampling rate of 1,000 Hz. At a walk, the iEMG values for the forelimb were not significantly different under any of the inclinations. In the hind limb, the iEMG values for the GM and BF significantly decreased as the inclination decreased. At a trot, the iEMG values for the Bc in the forelimb significantly decreased as the inclination of the treadmill decreased. In the hind limb, the iEMG values for the LD, GM, and BF significantly decreased as the inclination decreased. Uphill exercise increased the iEMG values for the Bc, LD, GM, and BF, while downhill exercise resulted in little increase in the iEMG values. It was concluded that the effects of inclination on the muscle activities were larger for the uphill exercises, and for the hind limb muscles compared with the forelimb muscles.

View full abstract

In order to reveal the preventive effect of marbofloxacin (MRFX) administration just before transportation, we compared the occurrence of transportation-associated fever before and after introduction of MRFX administration. After the introduction of prophylactic MRFX administration, the rectal temperatures of horses after transportation were significantly lower than before the introduction of MRFX administration (P<0.01) and the number of febrile horses was significantly lower than before the introduction of MRFX administration (P<0.01). In conclusion, these results show that prophylactic MRFX administration just before transportation is clinically effective at preventing transportation-associated fever.

View full abstract