Presumptive copper deficiency in hand-reared captive pronghorn (Antilocapra americana) fawns

Presumptive copper deficiency was diagnosed in hand-reared captive pronghorn (Antilocapra americana) at the Los Angeles Zoo. Clinical signs, which were manifested in growing fawns, included anemia, anorexia, diarrhea, progressive paresis/recumbency, and aortic rupture. The range of serum copper concentrations in fawns born during the 1989 season (0.08-0.67 ppm) was below levels considered normal for domestic sheep and goats (0.7-2.0 ppm) and below concentrations measured in adult pronghorn (0.4-1.43 ppm). Copper sulfate supplementation of the hand-rearing formula, which was initiated in 1989, resulted in a significant increase in mean (+/- SD) serum copper levels from 0.45 +/- 0.18 ppm before supplementation to 0.68 +/- 0.05 ppm after supplementation (P < 0.05). Fawns born in subsequent seasons (April 1990-August 1993) continued to be supplemented with copper in the hand-rearing formula. Mean serum copper concentration from these fawns (0.68 +/- 0.22 ppm) was similar to the mean values from supplemented 1989 fawns and adult pronghorn in this herd (0.85 +/- 0.34 ppm; P > 0.05). No clinical signs of copper deficiency were detected in any fawns after supplementation was started. Analyses of the herd's diet revealed marginal dietary copper levels. Suspected dietary deficiency was confirmed by marginal tissue and serum copper concentrations in some of the herd's adult animals. Dietary copper levels were corrected to prevent future cases of clinical copper deficiency.