RECOMMENDATION OF ANNUAL PHYSICALS FOR BUCEROS HORNBILLS
DUE TO RISK OF CASQUE SQUAMOUS CELL CARCINOMA
The captive population of giant/Indian hornbills (Buceros bicornis) reached a maximum population in 1983 of 79 birds but currently reports less than 50 birds in the SSP managed population. Since 1990, multiple reports (n=12) have documented invasive squamous cell carcinoma – the most recently in 2010 - of the casque with no gender predisposition. To date, no explanation has been found for the tendency of this neoplasia to occur in this location. Furthermore, extensive pathologic evaluation of both biopsies and post-mortem tissue has not determined an underlying infectious (bacterial, fungal, or viral) cause. To date, only B. bicornis has been identified at risk but the rhinoceros hornbill (B. rhinoceros) is sufficiently close taxonomically to warrant concern.
Plain radiography of the casque and skull in five standard views (both lateral, dorsoventral, ventrodorsal, and rostrocaudal) is the most sensitive tool for early detection of this fatal disease and should be considered annually. Digital images or copies of the radiographs should be submitted to the Veterinary Advisor for cataloguing and review to known SCC birds.
(Gamble, K.C. 2011. Squamous cell carcinoma in Buceros hornbills. In: Fowler, M.E., and R.E. Miller, eds. Zoo and Wild Animal Medicine, Current Therapy 7, in press.)