Canine and feline urinalysis: value of macroscopic and microscopic examinations

A retrospective survey of complete urinalyses performed on dogs and cats hospitalized at the University of Minnesota Veterinary Teaching Hospital was performed to determine the frequency of abnormal findings in urine sediment, compared with normal and abnormal macroscopic findings. One thousand consecutive urine samples collected from dogs and 1,000 consecutive urine samples collected from cats were studied. Results indicated that failure to examine urine sediment of macroscopically normal samples would have yielded false-negative results in 16.5% of the canine patients and 5.7% of the feline patients. Microscopic findings in macroscopically normal canine samples consisted primarily of pyuria and bacteriuria, whereas in cats they consisted of hematuria and bacteriuria. Microscopic abnormalities were detected in almost 50% of the canine and feline samples with macroscopic abnormalities. The results of this evaluation confirm the value of routine microscopic examination of urine sediment as a component of complete urinalysis.