Retrospective evaluation of renal disease in captive black howler monkeys (Alouatta caraya).

Six of 15 (40%) inactive medical records of adult black howler monkeys (Alouatta caraya) at one zoological institution included either a pre- or postmortem diagnosis of renal disease. In these six cases, significantly abnormal hematologic and serum chemistry values were reported at onset of azotemia, onset of clinical signs, and at euthanasia. Average age of onset of azotemia was 14.8 +/- 2.9 yr, with clinical signs of disease noted at 17 +/- 4.7 yr. In four of the cases (66.6%), azotemia was documented earlier than the onset of clinical signs of renal disease. Average duration of clinical disease was 2.83 +/- 1.6 yr, with an average age at euthanasia of 18 +/- 4.7 yr. Chronic tubulointerstitial nephritis with secondary glomerular sclerosis was present in all cases. Thirteen of an additional 20 institutions in the United States that have held Alouatta caraya responded to a survey for prevalence of renal disease. These institutions showed a lower prevalence (15.1%) of renal disease in complete, inactive records, a higher prevalence of glomerulonephritis, and similar significant clinicopathologic values.