A 5-year-old castrated male Golden Retriever was evaluated for
polyuria,
polydipsia, and progressive
regurgitation thought to be a result of
bacterial pyelonephritis and megaesophagus. Bacteriologic culture of
urine failed to yield clinically relevant
growth, and results of a
urine sediment examination were normal. With time, intention tremors and progressive neurologic dysfunction were also observed. At
necropsy, a diagnosis of cryptococcal disease was confirmed histologically and immunohistochemically. Findings in the dog of this report were indicative of
nephrogenic diabetes insipidus with
polyuria and
polydipsia caused by cryptococcal
pyelonephritis.
Neurologic manifestations of
systemic cryptococcus infection included megaesophagus, esophageal hypomotility, and
regurgitation attributed to
localization of cryptococcal
organisms in the
brain stem in the region of the dorsal motor nucleus of the
vagus nerve. To the authors' knowledge, this is the first report of
polyuria secondary to cryptococcal
pyelonephritis.