Management and prevention of vitamin D deficiency rickets in captive-born juvenile chimpanzees (Pan troglodytes)

Vitamin D deficiency rickets was diagnosed in three juvenile chimpanzees (Pan troglodytes) raised indoors under skylights and consuming only breast milk. Two cases detected early had mild but characteristic radiographic changes. More advanced disease presented with florid x-ray features of rickets and pathologic fractures, as well as hypocalcemia, hypophosphatemia, and low serum 25-hydroxyvitamin D levels. Treatment by a single injection of vitamin D₂ in sesame oil (slow release) followed by daily oral supplementation with vitamin D₂ corrected the condition. On the basis of experience with these cases and comparison with rickets in humans, a prevention protocol for mother-reared, inside-housed, chimpanzee juveniles was developed. Injection with slow release vitamin D₂ (5,000 IU i.m. once) at 4 mo of age, followed by oral supplementation of 400 IU vitamin D₂ daily until weaning, prevents rickets in juvenile chimpanzees raised indoors.