Saanane Island, Tanzania - Diceros bicornis. A pair of Black rhinoceroses Diceros bicornis bicorizis were brought to Saanane in late 1964. The female gave birth to a calf in May 1965. By July 1965, all three rhinoceroses were suffering from corneal opacities. Oral administration of vitamin A and supportive antibiotic therapy was introduced. Unfortunately, the calf died. The eye condition resolved completely in the male, but in the female serious damage to the internal structures of the eyes led to permanent blindness. In February 1966, this cow developed acute diarrhoea, and died three days after the onset of symptoms. Post-mortem examination showed that much of the mucosa of the large intestines was in the form of dried, hardened and raised diphtheritic plaques.
The bull rhinoceros subsequently showed bouts of diarrhoea which appeared to respond to vitamin A therapy. The administration of vitamin A was established as routine practice. Unexpectedly, in September 1967, this male had a peracute attack of diarrhoea and died within twenty-four hours. Post-mortem examination showed acute inflammation of the glandular part of the gastric mucosa. No clear-cut diagnoses were reached concerning the deaths of the rhinoceroses. It was felt, however, that dietary deficiencies were predisposing factors in the mortality.
