Objective—To evaluate results of SDS-agarose gel
electrophoresis (AGE) of urinary proteins for use in
defining glomerular and tubulointerstitial derangements,
investigate patterns of high-molecular-weight
(HMW) proteins for differentiating among glomerular
disorders, and assess low-molecular-weight (LMW) proteins
as markers of severity of tubulointerstitial disease
Animals—49 dogs with increased serum creatinine
concentrations or abnormal renal protein loss.
Procedure—Urinary proteins were examined by use
of SDS-AGE and differentiated on the basis of molecular
weight. The HMW proteins (≥ 69 kd) were considered
indicative of glomerular origin, whereas LMW
proteins (< 69 kd) were of tubular origin. Renal specimens
were examined by use of light microscopy.
Glomerular and tubulointerstitial lesions were differentiated
by use of the classification for the World
Health Organization and semiquantitative grading,
Results—Sensitivity of SDS-AGE was 100% for
detection of glomerular lesions and 92.6% for tubulointerstitial
lesions; specificity was 40% and 62.5%,
respectively. Although HMW urinary proteins were
not significantly associated with the type of glomerular
lesion, LMW urinary proteins were significantly
associated with the grade of tubulointerstitial damage.
Detection of 12- or 15-kd proteins or both was
highly indicative of a severe tubulointerstitial lesion.
Conclusions and Clinical Relevance—SDS-AGE of
urinary proteins in dogs represents a noninvasive test
with high sensitivity for identifying glomerular and
tubulointerstitial damage, but low specificity limits its
validity as a stand-alone test to differentiate between
glomerular and tubulointerstitial lesions. The test is
particularly useful for identifying dogs with advanced
tubulointerstitial disease but cannot be used to characterize
glomerular disorders. ( Am J Vet Res 2004;65:964–971)
Objective—To evaluate whether serial determinations of serum lactate dehydrogenase (LDH) activity in dogs with lymphoma could be used to predict outcome and assist in early recognition of disease progression.
Design—Prospective cohort study.
Animals—50 dogs with lymphoma.
Procedures—LDH activity was determined in dogs with newly diagnosed lymphoma or that had not received treatment. The LDH activity was measured at time of initial diagnosis, at completion of chemotherapy, and at 1, 3, and 6 months after chemotherapy. Treatment response and recurrence were recorded. At the end of chemotherapy and at each time point thereafter, the proportion of dogs in complete remission with elevated LDH activity was compared between dogs that did or did not have recurrence within the successive 45 or 90 days. Use of the LDH activity at admission to predict disease-free and survival intervals was evaluated.
Results—The proportion of dogs in complete remission with increased LDH activity at completion of chemotherapy and at 1 month after chemotherapy with recurrence during the successive 45 days was significantly higher (3/9 and 7/9 dogs, respectively) than the proportion of dogs without recurrence (0/32 and 1/26 dogs, respectively). At 3 or 6 months, only 1 dog without recurrence within 45 days had increased LDH activity. Increased LDH activity at time of diagnosis was not associated with disease-free and survival intervals.
Conclusions and Clinical Relevance—Determination of LDH activity may help with identifying episodes of recurrence in dogs with lymphoma. Anticipation of recurrence is an appropriate reason to begin rescue treatment.
Objective—To identify prognostic factors in cats with injection-site sarcomas (ISSs).
Design—Retrospective case series.
Animals—57 cats with ISSs.
Procedures—Medical records of cats were reviewed with regard to sex, age, anatomic site of tumor, tumor size, histologic grade, excision of a primary tumor versus excision of a recurrent ISS, use of excision alone versus excision plus adjuvant therapy, local tumor recurrence, and development of distant metastasis to predict overall survival time (ie, time from tumor excision to death).
Results—In univariate analyses, local recurrence and development of distant metastasis were significantly associated with survival time in cats. On multivariate analysis, development of distant metastasis remained a significant prognostic factor. Histologic grade was associated with distant metastasis, with cats having grade 3 tumors being significantly more likely to develop metastasis than cats with grade 1 and 2 tumors. Factors associated with local recurrence of ISSs were not identified.
Conclusions and Clinical Relevance—The development of distant metastasis, which may occur later during the course of the disease, was identified as a prognostic factor for overall survival time in cats with ISSs. In addition, cats with histologic grade 3 ISSs should be considered for further interventional studies with chemotherapy to prevent the high rate of distant metastasis.
Objective—To evaluate predictors of survival time in dogs undergoing adrenalectomy and identify risk factors associated with adrenal gland tumor metastasis and vein thrombosis.
Design—Retrospective case series.
Animals—52 dogs with primary adrenal gland tumors.
Procedures—Medical records were reviewed. Signalment, tumor features, and information from surgical procedures were evaluated to identify factors predictive of overall survival time, which was defined as the time from surgery until death. The association between metastasis or vein thrombosis and tumor type, size, and site (right or left adrenal gland) was investigated.
Results—On the basis of results of univariate analysis, survival time was significantly shorter for dogs with adenocarcinoma, tumor major axis length ≥ 5 cm, metastasis, and vein thrombosis and when adrenalectomy was combined with an additional abdominal surgical intervention. On multivariate analysis, survival time was significantly shorter for dogs with an adrenal gland tumor with major axis length ≥ 5 cm and for dogs with metastasis or vein thrombosis. Significant associations were found between metastasis and adenocarcinoma and between vein thrombosis and tumors with major axis length ≥ 5 cm.
Conclusions and Clinical Relevance—Dogs with an adrenal gland tumor with major axis length ≥ 5 cm, documented metastasis, or vein thrombosis had a poorer prognosis. Metastasis was more frequent in dogs with adenocarcinoma and vein thrombosis when tumors were ≥ 5 cm in length.
Objective—To evaluate a urine dipstick test as a possible replacement for urine protein-tocreatinine (UPC) ratio for identifying proteinuria in dogs.
Sample Population—507 urine samples from adult dogs.
Procedures—Urine dipstick, UPC ratio, specific gravity (USG), and sediment testing were performed on 507 samples. With UPC ratio as the reference criterion, diagnostic accuracy of the urine dipstick test was calculated for the entire data set and for urine samples grouped by USG (≤ 1.012 or > 1.012; < 1.030 or ≥ 1.030). A UPC ratio < 0.2 was used to indicate absence of proteinuria.
Results—The sensitivity of the urine dipstick test for detection of proteinuria was > 90% when 0 mg of protein/dL (a 0+ result) was used to indicate a negative test result, and the specificity ranged from 40% to 60%, depending on the USG. Sensitivity decreased to a range of 56% to 81% when 30 mg of protein/dL (a 1+ result) was used as the cutoff, depending on the USG, but the specificity increased to > 90%. The likelihood of correctly identifying nonproteinuric dogs was low when the USG was ≤ 1.012, particularly when samples with a 1+ result were considered negative.
Conclusions and Clinical Relevance—For dogs with a dipstick-test result of 1+ and USG ≤ 1.012, proteinuria should be assessed by use of the UPC ratio; dogs with a USG value > 1.012 are likely nonproteinuric. When used together, the urine dipstick test and USG measurement were reliable as a rapid alternative to UPC ratio determination in dogs in this study.
Case Description—A 6-month-old domestic shorthair cat was evaluated because of acute lethargy.
Clinical Findings—Severe nonregenerative anemia and thrombocytopenia were identified. Cytologic examination of a bone marrow aspirate revealed selective erythroid and mega-karyocytic aplasia and a high number of apparently normal small lymphocytes. Infectious agents implicated in feline hematologic disorders were excluded on the basis of serologic tests or PCR amplification, including FeLV, Ehrlichia canis, Anaplasma phagocytophilum, Mycoplasma haemofelis, Candidatus Mycoplasma haemominutum, and Candidatus Myco-plasma turicensis.
Treatment and Outcome—A 10-day course of prednisolone administration did not improve the hematologic disorder. Administration of human polyclonal immunoglobulins preceded increased reticulocyte count by 3 days. A second bone marrow examination confirmed restoration of erythroblasts and megakaryocytes. After 1 relapse, the disease was successfully controlled with prednisolone for > 3 years.
Clinical Relevance—Immune-mediated bone marrow aplasia is rare in cats and usually affects only erythrocyte progenitors. Concomitant involvement of erythroid and megakaryocytic cell lines can be successfully treated via immunosuppressive therapy. Human immunoglobulins seem to be well tolerated in cats; however, proof of a beneficial effect requires further study.
Objective—To determine results of cytologic examination of fine-needle aspirates and impression smears of gastrointestinal tract tumors in dogs and cats.
Design—Retrospective case series.
Animals—38 dogs and 44 cats with histologically confirmed gastrointestinal tract tumors.
Procedures—Results of cytologic examination of fine-needle aspirates (n = 67) or impression smears (31) were compared with the histologic diagnosis, and extent of agreement was classified as complete, partial, none, or undetermined.
Results—For 48 of the 67 (72%) fine-needle aspirates, there was complete or partial agreement between the cytologic and histologic diagnoses. For 12 (18%) aspirates, the extent of agreement could not be determined because the cytologic specimen was considered unsatisfactory. For 29 of the 31 (94%) impression smears, there was complete agreement between the cytologic and histologic diagnoses, and for 2 (6%), there was partial agreement. None of the impression smears were considered unsatisfactory. Proportion of samples with complete agreement and proportion of samples with complete or partial agreement were significantly higher for impression smears than for fine-needle aspirates.
Conclusions and Clinical Relevance—Results suggest that there was moderate agreement between results of cytologic examination of fine-needle aspirates from dogs and cats with gastrointestinal tract neoplasia and the definitive histologic diagnosis. The agreement between results of cytologic examination of impression smears and the histologic diagnosis appeared to be higher.
Objective—To investigate whether combined treatment with gemcitabine and piroxicam in dogs with transitional cell carcinoma (TCC) of the urinary bladder is tolerated and provides an advantage in terms of survival time over previously reported treatments.
Animals—38 dogs with TCC of the urinary bladder.
Procedures—Dogs were treated with gemcitabine (800 mg/m2, IV over 30 to 60 minutes, q 7 d) and piroxicam (0.3 mg/kg [0.14 mg/lb], PO, q 24 h). Complete blood cell counts were monitored prior to each gemcitabine treatment. All toxic effects of gemcitabine in dogs were recorded. Primary tumors were ultrasonographically reevaluated after 4 gemcitabine treatments.
Results—Dogs received a median of 8 gemcitabine treatments (range, 1 to 38 treatments/dog). In response to treatment, 10 of 38 (26.3%) dogs had grade 1 gastrointestinal tract signs, 11 (28.9%) had grade 2, and 5 (13.2%) had grade 3. Grade 1 neutropenia developed in 6 (15.8%) dogs and grade 2 and 3 neutropenia in 2 (5.3%) dogs each. Thrombocytopenia was rare. All dogs had improvement of clinical signs of disease. Two dogs had a complete tumor response, 8 had a partial response, 19 had stable disease, and 8 had progressive disease. Median survival time with treatment was 230 days.
Conclusions and Clinical Relevance—Administration of gemcitabine in combination with piroxicam treatment failed to provide a longer overall survival time in dogs with TCC of the urinary bladder, compared with previously reported treatment strategies. However, this combination of chemotherapy did provide a new treatment alternative with fewer adverse effects.
Objective—To assess whether urine protein-to-creatinine (UPC) ratios determined in urine samples collected by cystocentesis versus those collected by free catch provide similar diagnostic information for dogs.
Animals—115 client-owned dogs evaluated because of various health problems requiring urinalysis or to screen for proteinuria in an area endemic for leishmaniasis.
Procedures—230 paired urine samples, 1 collected by cystocentesis and 1 by free catch, were collected from the 115 dogs. The UPC ratio was determined in paired urine samples (n = 162) from 81 dogs with no indication of active inflammation according to urine sediment analysis. On the basis of the UPC ratio of urine sample collected by cystocentesis, dogs were classified as nonproteinuric (UPC ratio < 0.2), borderline proteinuric (UPC ratio of 0.2 to 0.5), or proteinuric (UPC ratio > 0.5), according to the International Renal Interest Society (IRIS).
Results—The correlation between UPC ratio in urine samples collected by cystocentesis and by free catch was strong (r2 = 0.90); 75 of 81 (92.6%) dogs had UPC ratios from both urine samples that resulted in classification in the same IRIS substage with a kappa coefficient of 0.83.
Conclusions and Clinical Relevance—The UPC ratio in dogs was minimally affected in urine samples collected by free catch, thus allowing correct grading of proteinuria with this method. The high reliability of the UPC ratio in free-catch urine samples coupled with the ease of collection should increase the use of this value for assessment of proteinuria.
Objective—To determine whether preanalytic and analytic factors affect evaluation of the urinary protein-to-creatinine (UPC) ratio in dogs.
Sample—50 canine urine samples.
Procedures—The UPC ratio was measured to assess the intra-assay imprecision (20 measurements within a single session), the influence of predilution (1:10, 1:20, and 1:100) for urine creatinine concentration measurement, and the effect of storage at room temperature (approx 20°C), 4°C, and −20°C.
Results—The coefficient of variation at room temperature determined with the 1:20 predilution was < 10.0%, with the highest coefficients of variation found in samples with a low protein concentration or low urine specific gravity. This variability could result in misclassification of samples with UPC ratios close to the thresholds defined by the International Renal Interest Society to classify dogs as nonproteinuric (0.2), borderline proteinuric (0.21 to 0.50), or proteinuric (> 0.51). A proportional bias was found in samples prediluted 1:10, compared with samples prediluted 1:20 or 1:100. At room temperature, the UPC ratio did not significantly increase after 2 and 4 hours. After 12 hours at room temperature and at 4°C, the UPC ratio significantly increased. The UPC ratio did not significantly change during 3 months of storage at −20°C.
Conclusions and Clinical Relevance—The intra-assay precision of the UPC ratio was sufficiently low to avoid misclassification of samples, except for values close to 0.2 or 0.5. The optimal predilution ratio for urine creatinine concentration measurement was 1:20. A 1:100 predilution is recommended in samples with a urine specific gravity > 1.030. The UPC ratio must be measured as soon as samples are collected. Alternatively, samples should be immediately frozen to increase their stability and minimize the risk of misclassification of proteinuria.