Collaboration Across Institutions and Across Continents Facilitates Advancements in the Diagnosis and Management of Chronic Respiratory Disease of Orangutans (Pongo spp.)
Orangutans (Pongo spp.), unlike other species of great ape, have a high incidence of chronic respiratory disease that can reduce quality of life, shorten lifespan, prematurely eliminate individuals from the gene pool, and drain institutional resources. This devastating clinical syndrome, Chronic Respiratory Disease of Orangutans (CRDO), affects orangutans at more than half of the zoos in the USA and Europe.5,7,12 It consists of chronic, recurrent, progressive infection of the sinuses, air sacs, cranial bones, and lungs.2-4,6,8,9-11 Parallel lines of investigation into the environmental and genetic risk factors for CRDO are helping to shed light on this complex condition.1,11,12 However, such studies are hindered by the small number of individuals at institutions in America and Europe. The Bornean Orangutan Survival Foundation (BOSF) houses up to 700 orangutans in two rescue centers in East and Central Kalimantan, Indonesia. The incidence of CRDO at the Samboja Lestari rescue center in East Kalimantan exceeds 10% of the population. Twenty-five individuals from 7 to 23 years of age have been affected with CRDO for a period of one to ten years, based on the clinical symptoms of nasal discharge, behavioral evidence of headache, air sacculitis, coughing, and wheezing. This group of twenty-five animals provides an ideal study cohort for the evaluation of diagnostic and therapeutic approaches to CRDO.
The goals of the preliminary work with this population of affected orangutans are to: 1) establish a clinical definition of CRDO; 2) establish a scale of severity for prognostic purposes; 3) establish diagnostic standards using a variety of tools; 4) create a library of orangutan respiratory pathology based on in computed tomography (CT) imaging; and 5) conduct preliminary therapeutic trials using modifications of accepted cystic fibrosis treatment protocols.
Achievement of these goals requires close collaboration across many institutions. Experts from the European Association of Zoos and Aquariums Orangutan European Endangered species Programme have broad expertise in the medical and surgical management of chronic sinusitis in orangutans, as well as the assessment of CRDO from the standpoints of animal welfare and environmental risk factors. Experts from the Association of Zoos and Aquariums Orangutan Species Survival Plan bring experience in the assessment and management of bronchiectasis/chronic pneumonia and inoperant conditioning to facilitate treatment. Expertise from cystic fibrosis specialists and investigators at National Jewish Health in the United States is necessary for the design of targeted treatment trials as well as genetic investigation. The veterinary teams at BOSF have the most experience of anyone in the world in the daily challenges of CRDO diagnosis and treatment, having managed over 40 cases and 100 air sac marsupializations in the past 10 years!
This team has made significant progress in the past two years and expects to have completed the five listed goals by the end of 2019. CRDO definition, severity scale, and diagnostic standards are in progress. The library of CT images of orangutan respiratory pathology, when complete, will be made available to medical professionals working with orangutans.
The results of a preliminary treatment trial are very encouraging. Accepted cystic fibrosis treatment modalities needed some modification based on product availability in Indonesia, but it was possible to stay within the same drug classes on the same treatment schedule. An 8-week treatment trial resulted in clinical improvement in the three animals studied. The first noted change being a cessation of nasal discharge. Coughing was also reduced. Attitude and appetite improved. Post-treatment CT images showed significant improvement in respiratory pathology.
This work illustrates the benefits achieved when captive and range country professionals collaborate toward a common goal. Results of this work have the potential to improve the health and welfare of orangutans in zoos around the world, while directly contributing to in situ conservation efforts in rehabilitation and reintroduction programs.
The authors sincerely thank the management, veterinary and animal care staff of the Bornean Orangutan Survival Foundation for their continued support of this important work. Thank you to Dr. Taylor-Cousar, and Saint Joseph’s Hospital for equipment and product donation and professional consultation. We also thank Cara Gomez, RT (Adult CF Program, National Jewish Health) for her expertise and support.
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