Victoria L. Clyde1,3*, DVM; Robert Korman1, CVT, VTS (Anesthesia); Samuel Wann2,3, MD, MACC, FAHA, FESC; Leann Beehler3, LPN, RDCS
1Milwaukee County Zoo, Milwaukee, WI, USA; 2Columbia St. Mary’s Healthcare, Milwaukee, WI, USA; 3Bonobo Cardiovascular Database of the Bonobo Species Survival Plan, Milwaukee, WI, USA
Like other species of captive great apes, cardiovascular disease (including sudden death, myocardial fibrosis, hypertension, aortic dissection and stroke) is a major cause of mortality in adult bonobos.1 The ability to measure indirect blood pressure in non-anesthetized animals is critical in order to identify hypertension, institute timely anti-hypertensive treatment, and monitor response to anti-hypertensive and cardiac medications in bonobos with heart disease in order to optimize dosages. The Milwaukee County Zoo has been successful in obtaining indirect blood pressure measurements using finger cuffs and a dual channel oscillometric hand-held device on awake bonobos trained to participate through positive reward operant conditioning, and is collecting data to develop normal reference ranges for bonobos. This technique has already identified bonobos with apparent hypertension and documented reduction in finger blood pressure measurements after treatment with ACE inhibitors or beta-blockers. Most importantly, this technique allows clinicians to modulate medication dosages based on a measureable therapeutic endpoint. The effective dose of these drugs appears to vary between bonobos, as it does in humans.2 Echocardiography in both awake and anesthetized bonobos has documented reduction in left ventricular size after treatment with ACE inhibitors. The ability to measure blood pressure in awake bonobos will help define critical points for therapeutic intervention, and develop effective dosage ranges of anti-hypertensive and cardiac medications in bonobos.
The authors thank the animal care staff of the Sterns Family Apes of Africa and Primates of the World at the Milwaukee County Zoo for their exceptional care and training programs that allow for voluntary participation of the bonobos in their medical care and treatment.
1. McManamon R, Lowenstine L. Cardiovascular disease in great apes. In: Miller RE, Fowler ME (eds.) Zoo and Wild Animal Medicine, vol. 7, Current therapy. St. Louis (MO): Elsevier; 2012:408–415.
2. Reddy P, DuPree L. Approach to Antihypertensive Therapy. Am J Ther [Internet]. 2015 [cited 2015 August 6]; Epub ahead of print. Available from: doi:10.1097/MJT.0000000000000224