Are fast-moving elephants really running?

Abstract

Objective: To describe the clinical characteristics and outcomes in a population of dogs with negative-pressure pulmonary edema (NPPE) and to identify the main causes of the disease. To evaluate any associations with morbidity and mortality.Design: Retrospective study.Setting: Three university teaching hospitals and two private referral centers.Animals: Thirty-five client-owned dogs presented with NPPE. Interventions: NoneMeasurements and Main Results: Data collected included patient characteristics, clinical history, clinicopathological abnormalities, radiographic features, treatments and outcome. Median age was 4 months (range 2-90) and median weight was 7.1 kg (range 1.7-37.2). There were many causes of NPPE including leash tugs, near hanging, accidental choking, anatomical obstruction to airflow and purposeful airway obstruction by people. The most common cause of NPPE was accidental choking (40% of cases). Dogs with an anatomical obstruction were older than 24 months. Hypoxemia with an increased alveolar-arterial gradient was common on presentation. The majority of thoracic radiographs (65.7%) showed an alveolar or interstitial pattern in the caudodorsal area as previously described in the literature. Oxygen therapy was administered to 33 (94.3%) dogs. Furosemide was administered to 18 (51.4%) dogs. Median length of hospitalization was 2 days (range 0-14). Twenty-eight (80%) dogs survived to discharge. Seven dogs were mechanically ventilated and only 2 of them (28.6%) 2 survived to discharge. Requirement for mechanical ventilation (p<0.001) was the only parameter associated with mortality.Conclusions: Most cases of NPPE occur in juvenile dogs. Different incidents associated with upper airway obstruction can produce an episode of NPPE.Choking on food or toys and near hanging have not been previously described in the veterinary literature as inciting causes of NPPE. The overall prognosis is good.

The three-dimensional locomotor dynamics of African (Loxodonta africana) and Asian (Elephas maximus) elephants reveal a smooth gait transition at moderate speed

“…Elephants do not normally trot or gallop, even as juveniles, but they can move smoothly to fairly fast speeds (approx. 6.8 m s K1 ) without changing their lateral sequence footfall pattern (Hutchinson et al 2003). Their locomotor pattern at their faster speeds is atypical of most familiar quadrupedal animals (Muybridge 1899;Gambaryan 1974;Hildebrand 1985).…”

“…However, when applied to the fast moving elephants, they are partly contradictory (Hutchinson et al 2006). Previous studies doubted whether fast moving elephants were merely walking (Hutchinson et al 2003), but the speed at which any potential gait transition occurred was left open, although it was concluded that near a dimensionless speed of 1.0 (equal to Fr 0.5 , 1.0) elephants probably were running, in the mechanical sense of the term.…”

“…Elephants are unusual not only in their enormous size, but also in their special locomotor pattern (Hutchinson et al 2003(Hutchinson et al , 2006. Elephants do not normally trot or gallop, even as juveniles, but they can move smoothly to fairly fast speeds (approx.…”

“…Fast moving elephants exceed Froude numbers (Fr, where FrZvelocity 2 ! (gravitational acceleration!hip height) K1 ) of 1.0, even reaching Fr 3.4 (Hutchinson et al 2003), speeds at which most other quadrupedal mammals gallop (Alexander & Jayes 1983). Across their entire speed range, elephants constantly keep at least one foot on the ground; they never change their footfall pattern to one that uses a whole-body aerial phase (Hutchinson et al 2003(Hutchinson et al , 2006.…”

“…Although basic information on footfall patterns and other stride parameters are now available, providing hints that a bouncing gait (i.e. running in a biomechanical sense; Farley et al 1993;Ruina et al 2005) may be used at moderate to near-maximal speeds (Hutchinson et al 2003(Hutchinson et al , 2006, there are still wide gaps in the fundamental understanding of elephant locomotion.…”