Brain Natriuretic Peptide as a Novel Diagnostic and Prognostic Indicator of Cardiac Disease in Gorillas: Two Case Reports
Cardiac disease is a leading cause of death in captive adult western lowland gorillas (Gorilla gorilla gorilla).4 Recent evidence suggests that affected gorillas may present acutely or may remain subclinical for extended periods. The progression of two cases of gorilla cardiac failure—one acute and one chronic—are compared and contrasted by examining serial cardiac ultrasound examinations over 10 years in conjunction with a novel blood test, brain natriuretic peptide (BNP).
In humans, BNP is a sensitive and noninvasive method of diagnosing congestive heart failure, monitoring response to treatment, and determining prognosis.3 This peptide is secreted by the ventricles in response to myocardial stretching, and levels are significantly increased in patients with cardiac disease.1 Brain natriuretic peptide appears to be a more sensitive test for diagnosing certain types of cardiac failure than measuring left ventricular ejection fraction alone.2,3 In humans a BNP level of >100 pg/ml diagnoses congestive heart failure with 90% sensitivity, 76% specificity, and 83% predictive accuracy.1
In a preliminary study to determine the value of BNP as a diagnostic test and prognostic indicator for cardiac disease in gorillas, banked blood from the two adult male gorillas at the Smithsonian National Zoological Park was analyzed for BNP levels and compared with ultrasound examinations taken at the same time. The retrospective analysis of BNP levels in these two cases suggests that BNP may be a novel and effective method of diagnosing and monitoring cardiac disease in gorillas.
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3. Doust, J.A., E. Pietrzak, A. Dobson, and P.P. Glasziou. 2005. How well dose B-type natriuretic peptide predict death and cardiac events in patients with heart failure: systematic review. Brit. Med. J. 330:625–633.
4. Meehan, T.P. and L.J. Lowenstine. 1994. Causes of mortality in captive lowland gorillas: A survey of the SSP population. Proc. Am. Assoc. Zoo Vet. Annu. Meet. Pp. 190–192.