Proventricular dilatation in a Cockatoo
History: A male adult Cockatoo had regurgitated. His feed was changed but continued to regurgitate, and died within a few days.
The bird was very thin with a very prominent keel bone and pectoral muscle atrophy.
The crop and proventriculus were markedly dilated and filled with soft oats. The proventriculus filled 80% of the cranial coelom and displaced the liver dorsally and to the right. The ventriculus was displaced caudally and displaced the intestines dorsally. The intestines contained a small amount of brown liquid.
Large artery: There is disruption of the internal elastic lamina and there is accumulation of pale basophilic mucinous material within the tunica muscularis of the artery.
Brain: In the cerebrum there are moderate numbers of small blood vessels surrounded by small numbers of lymphocytes and plasma cells in the grey and white matter.
Causes of proventricular dilatation include Bornavirus, lead intoxication, foreign body obstruction, fungal infection, megabacterial infection or neoplasia. Bornavirus infection (proventricular dilatation disease) causes inflammation in the central and peripheral nervous systems. We did not see any inflammation in the peripheral nerves, proventriculus, ventriculus, crop or esophagus. In the absence of inflammation of in peripheral ganglia/nerves we could not definitively diagnose this case as a “proventricular dilatation disease”. However, since no fungi, bacteria, neoplasia, obstruction or other evidence of lead toxicity, Bornavirus is the most likely cause/agent of disease in this case.