Cheetahs are the fastest land animal. Their galloping shows three characteristics: small vertical movement of their center of mass, small whole-body pitching movement, and large spine bending movement. We hypothesize that these characteristics lead to enhanced gait performance in cheetahs, including higher gait speed. In this study, we used a simple model with a spine joint and torsional spring, which emulate the body flexibility, to verify our hypothesis from a dynamic perspective. Specifically, we numerically searched periodic solutions and evaluated what extent each solution shows the three characteristics. We then evaluated the gait performance and found that the solutions with the characteristics achieve high performances. This result supports our hypothesis. Furthermore, we revealed the mechanism for the high performances through the dynamics of the spine movement. These findings extend the current understanding of the dynamic mechanisms underlying high-speed locomotion in cheetahs.

Cheetahs (Acinonyx jubatus) are classified as \"vulnerable\" species due to the low numbers persisting in the wild. Gastrointestinal diseases are very common in this species when they are kept in captivity, in particular gastritis. Clinical signs are predominantly characterized by vomiting, diarrhea, weight loss and anorexia. In this study, we evaluated the efficacy of a multi-strain probiotic in two groups of cheetahs: Group A (n = 4)-rescued cheetahs housed at the Cheetah Conservation Fund (Otjiwarongo, Namibia); Group B (n = 9)-captive cheetahs housed in Italian zoos. Animals showed gastrointestinal signs of different severity, and were positive for Helicobacter spp., detected by PCR in stool samples. Two sachets of probiotic formulation were administered to all cheetahs once a day for 21 consecutive days. Clinical conditions (appetite loss, vomiting, stool consistency and Body Condition Score) before (T0) and after 21 days of probiotic administration (T1) were then compared using a simplified Feline Chronic Enteropathy Activity Index (FCEAI) score. A slight but not significant improvement in the scores was observed in Group A, which had mild intestinal symptoms, while a significant decrease in vomiting and stool consistency (**p < 0.01) scores was observed in Group B, which had more pronounced symptoms. Results suggest that high concentrations of live probiotics can be of help in managing gastrointestinal signs in cheetahs.

Focal palatitis (also known as focal palatine erosion) is thought to be a developmental disease, specifically of cheetah in captivity raised on a commercial diet. The lack of chewing is thought to cause the mandibular molar to change angulation, contacting the palate and causing the lesions. We followed the development of five captive cheetah cubs, born within 2 weeks of each other, at the same facility. This longitudinal study followed the cubs cephalometrically from 7-months-old to 25-months-old. Of each cub we made a lateral and dorsoventral radiograph at 7, 13, 20, and 25-months-old. For each radiograph at each age, a predefined series of measurements were made including the angle of the molar. The latter was measured as the angle of the bisecting line running through the apex of the caudal molar root intersecting with a line drawn at the ventral margin of the mandible. The results confirmed that the cheetah skull and neurocranium follows the same neural growth pattern as has been described for other mammalians. Similarly the maxillofacial component follows the same somatic growth as seen in all mammalians excluding humans and non-human primates, where a pubertal growth spurt is present. Finally the angle of the mandibular molar at 7 months differed significantly from the angle at the other ages, however there were no statistical difference in the angulation of the molar after eruption (13 months and older ages). In these five cheetah the lack of chewing (as seen in captivity with a commercial or meat only based diet) did not alter the angulation of the mandibular molar, nor did the mandibular molars super erupt in these patients at 25-months-of-age.

The enrichment practice of the \"cheetah run\" is becoming increasingly popular within zoological institutions as a method to enrich captive cheetahs. A lure moving at speed represents an artificial prey item that the cursorial cheetah can pursue, therefore allowing it to perform an important hunting behavior within a captive setting. This study was conducted in order to highlight how employing different forms of this type of enrichment may influence its efficacy. This is important in relation to the future development of an optimum type of \"cheetah run\" enrichment which maximizes the potential beneficial effects and therefore positively impacts upon cheetah welfare in captivity. Video recordings were carried out at three separate institutions (Fota Wildlife Park, Ireland; Ann van Dyk Cheetah Centre, South Africa; Cheetah Conservation Fund, Namibia). Randomization tests were carried out to compare the highest speeds attained between males and females, trained and untrained cheetahs and also between the three institutions. Females and trained individuals reached significantly higher speeds compared with males and untrained individuals, respectively. The only significant difference between the three institutions was between the Ann van Dyk Cheetah Centre and the Cheetah Conservation Fund, where cheetahs at the Ann van Dyk center reached significantly higher speeds. The current study represents the first detailed study of any aspect of the \"cheetah run\" across multiple institutions. It also includes the first quantification of the speed of cheetahs in captivity in relation to differing enrichment practices.