Degenerative joint disease in captive waterfowl

A retrospective study was conducted to evaluate degenerative joint disease (DJD) in captive waterfowl that died or were euthanized at Fresno's Chaffee Zoo in Fresno, California, USA from 2001 to 2005. Of these, 16 out of 33 birds (48%) had DJD in one or both stifle (femoral-tibiotarsal joint; n = 13), hock (tibiotarsal-tarsometatarsal joint; n = 4), or toe joints (n = 2), based on gross, histologic and/or radiographic confirmation. No joint disease was observed in any wings, nor were any infectious pathogens isolated from affected joints. Sixteen species of waterfowl were included (n = 1 to 5 per species), with an average age at death of 12.1 years and 11.3 years for waterfowl with, and without DJD, respectively. Neither age nor sex was associated with the presence of joint disease. Waterfowl housed in the Rainforest exhibit were more likely to be diagnosed with DJD compared with waterfowl housed in the duck pond exhibit, possibly due to the rough-textured concrete surfaces in the Rainforest exhibit. Further research involving a larger number of zoological collections and birds is necessary to gain a better understanding of risk factors in captive waterfowl.