This study examined the effects of shade provision on some physiological parameters and draft performance of pack donkeys (Equinus asinus) during the packing period of the hot-dry season. Ten donkeys provided with shelter in the form of an open-sided shade after packing work served as the experimental animals. Another ten donkeys not provided with shade served as the control. Rectal temperature (RT, °C), heart rate (HR, beats per minute) and respiratory rate (RR, breaths per minute) recorded pre- and post- packing indicated that unshaded donkeys had significantly (P<0.05) higher values than shaded donkeys pre- and post-packing. The frequency of lying bouts per unshaded donkey was higher in the (P<0.05) pre- and post-packing periods; while the time spent by the donkeys lying down was lower (P<0.01) in unshaded donkeys than the shaded donkeys, apparently due to the high (53.5 ± 0.1-55.2 ± 0.3°C) soil temperature. The percent change in RT, HR, RR and liveweight loss values was higher (P<0.05) in unshaded donkeys. The change rate in behavioral values, except for the frequency of lying down and the donkeys speed, was not different (P>0.05) between the shaded and unshaded donkeys. The pack load and the distance covered by the donkeys in both groups were not significantly (P>0.05) different. The speed of shaded donkeys was significantly (P<0.05) faster than that of the unshaded donkeys during packing. Packing increased (P<0.05) the time spent by the donkeys in eating and drinking in both groups. In conclusion, the provision of shade during the hot-dry season alleviates work and heat stress and enhances work productivity in pack donkeys.

View full abstract

The purpose of this study was to describe the characteristics of fast race horses by analyzing the running form of Deep Impact, the undefeated Japanese triple crown winner in 2005. A high-speed video data of the Kikuka Syo race (Japanese St. Leger, JPN G1, 3,000 m, turf) was taken at a rate of 250 frames/sec. The high-speed video system was set in a left lateral position about 100 m before the finishing post with a field view width of about 16 m. The speed of Deep Impact, 17.8 m/sec, was the fastest of all horses measured (average 16.1 m/sec), the stride frequency, 2.36 strides/sec, was the third largest (average 2.28 strides/sec), and the stride length, 7.54 m, was the longest (average 7.08 m). The diagonal and airborne step lengths of Deep Impact were longer than the average values. The overlap time of Deep Impact was shorter than the average value. The ratio of overlap time to stride duration of Deep Impact was 8.5 %, whereas the average value was 16.9 %. A shorter overlap time was also observed on a common characteristic of Secretariat, the famous elite race horse in USA and correlated to running speed. Thus, these characteristics may be related to effective running form in elite horses.

View full abstract

A 17-year-old, gray Thoroughbred gelding was presented with recurrent epistaxis following exercise for over one year. Multidetector-row computed tomographic (MDCT) examination of the head performed under general anesthesia indicated the presence of malignant melanoma. MDCT examination revealed the exact location and size of masses in the right guttural pouch first identified by endoscopy and in the left guttural pouch unidentified by endoscopy. MDCT examination revealed the presence of a blood clot that filled the right maxillary sinus. The horse was euthanized due to poor prognosis as a riding horse and the owner's decision, and MDCT findings were confirmed by postmortem examination. MDCT is suggested as a useful technique for diagnosis of head problems such as neoplasia and sinusitis which are typically difficult to detect by endoscopy.

View full abstract

The pathology of aortic-iliac thrombosis(AIT) in two adult Thoroughbred horses from the same breeding farm is reported. No. 1 showed sudden falls with moaning and profuse sweating at mating and during hard exercise repeatedly for more than two years. The symptoms subsided within several tens of minutes. No. 2 showed intermittent lameness of the left hind leg progressively for more than three years. In both horses, thromboembolism was observed in the abdominal aorta, terminal quadrifurcation, and branchial arteries bilaterally. Arterial intima without adherent thrombi had formed intimal plaques frequently. Other noticeable changes were parasitic aneurysm and Hemomelasma ilei. From these findings of the two cases it is suggested that AIT is one of the pathological conditions caused by Strongylus vulgaris infection.

View full abstract