A Retrospective and Prospective Study of Megaesophagus in the Parma Wallaby (Macropus parma) at the San Diego Zoo, California, USA

Abstract

At the San Diego Zoo (California, USA), 22 cases of megaesophagus were diagnosed in the parma wallaby (Macropus parma); a prevalence of 21.1%. Parma wallabies often have no clinical signs until severe and chronic dilation of the esophagus is present. Clinical signs of advanced disease include weight loss, swelling of the cervical region, regurgitation without reswallowing of ingesta, short flight distance, depression, collapse, dyspnea, and sudden death. Retrospective and prospective studies at the San Diego Zoo and a multi-institutional survey in the United States were used to try to determine the cause of megaesophagus. The retrospective study did not identify an etiology. The prospective study revealed megaesophagus and severely delayed esophageal transit time in eight of eight animals. Myasthenia gravis, lead toxicosis, toxoplasmosis, and thyroid disease were eliminated as possible causes. Of 286 living and dead parma wallabies surveyed at other institutions, three cases of esophageal diverticulum and one case of megaesophagus were reported. The cause of megaesophagus in parma wallabies was not determined.

A Retrospective Study of Macropod Progressive Periodontal Disease (“Lumpy Jaw”) in Captive Macropods across Australia and Europe: Using Data from the Past to Inform Future Macropod Management

“…Retrospective studies, including those that make use of zoo records, are an indispensable tool in the identification of disease patterns [ 3 , 31 , 32 , 33 ], and can also be used to evaluate the efficacy of interventions, such as modifications to husbandry practices, aimed at reducing the incidence of a disease [ 34 , 35 ]. Studies such as this provide important information from which zoological institutions can make management decisions that may reduce the risk of MPPD and help to conserve the health and welfare of macropods in captivity.…”

Ampicillin‐resistant Actinobacillus pleuropneumoniae in pigs

“…No underlying cause of the megaoesophagus was identified. In a recent review by Burgdorf‐Moisuk and colleagues (2012), it was reported that megaoesophagus in parma wallabies is common and that clinical signs of advanced disease include weight loss, collapse, dyspnoea and sudden death; no underlying aetiology was established and the authors speculated about unrecognised environmental or nutritional causes.…”

Arterial Circle of the Brain of the Red-Necked Wallaby (Notamacropus rufogriseus)

“…Wallaby medicine is a developing branch of veterinary medicine worldwide [ 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 ]. Among the diseases described in the literature, parasitic infestations [ 12 ], bacterial diseases of the oral cavity [ 13 ], and cardiomyopathies can be mentioned [ 8 ].…”