7. UROBILINOGEN TEST PADS have not been useful in the routine evaluation of canine and feline urine. A computer search of approximately 11,000 canine urinalysis records yielded only 0.015 percent positive urobilinogen tests. A computer search of approximately 2,070 feline urinalysis records yielded only 0.02 percent positive urobilinogen tests, and of these, only 14 were equal to or greater than 1+.

TIP: Urobilinogen test pads are unreliable to screen patients for hemolytic disorders, hepatic disorders or patency of bile ducts. We typically ignore this test result.

8. NITRITE TEST PADS used as an indirect indication of bacteriuria in humans uniformly give false-negative results in dogs and cats. Available information indicates that false-negative results probably are associated with interference caused by ascorbic acid normally present in canine and feline urine.

9. LEUKOCYTE TEST PADS give false-positive test results in most cats in absence of pyuria.

TIP: Evaluate fresh urine sediment to determine the presence or absence of leukocytes in cats.

10. LEUKOCYTE TEST PADS frequently give false-negative test results in dogs, even when pyuria is present. Although the test is specific for WBC in dogs, it is very insensitive.

TIP: Evaluate fresh urine sediment to determine the presence or absence of leukocytes in dogs.

What is your interpretation of the following urinalysis results?

The following nine case scenarios are designed to facilitate self-assessment of your interpretation of routine urinalysis of several patients admitted to the Veterinary Teaching Hospital, University of Minnesota.

When choosing your answer, remember to distinguish between observations and interpretations, and to consider the best answer in terms of probabilities rather than possibilities.

Please note that hpf means high-power microscope field (450 X), and lpf means low-power microscope field (100 X). See the end of the discussion for my explanations of these answers.

CASE 1

Consider the following results obtained by analysis of a urine sample obtained during normal voiding from a 7-year-old spayed yellow Labrador Retriever.

Color - light yellow
Protein - 4+
Turbidity – clear
RBC - 1 - 2 /hpf
Specific gravity - 1.025
WBC- 0 - 1 /hpf
pH - 6.0
Casts - occasional hyaline/lpf.
Glucose – negative
Epithelial cells – occasional
Acetone – negative
Bacteria – none
Bilirubin – negative
Crystals – none
Occult blood - negative

The best interpretation of the results of this urinalysis is that the patient:

a. Is normal.
b. Has generalized glomerular disease.
c. Has an inflammatory process somewhere along the urinary tract.
d. Has generalized tubular disease.
e. Has findings indicative of congestive heart failure or fever.

CASE 2

Consider the following results obtained by analysis of a voided urine sample from an 8-year-old, male Basset Hound:

Color –yellow
Protein – 1+
Turbidity – clear
RBC - 1 - 2 /hpf
Specific gravity - 1.060
WBC- 0 - 1 /hpf
pH – 7.0
Casts - none
Glucose – negative
Epithelial cells - occasional
Acetone - negative
Bacteria - none
Bilirubin - 1+
Crystals - few amorphous
Occult blood - negative