Search Results

Abstract

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 in dogs.

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, respectively.

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)

Abstract

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.

Abstract

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.

Abstract

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.

Abstract

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.

Abstract

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.

Abstract

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.

Abstract

Objective—To determine overall survival time and identify prognostic factors associated with survival time in cats with newly diagnosed diabetes mellitus.

Design—Retrospective case series.

Animals—114 cats with newly diagnosed diabetes mellitus.

Procedures—Data for analysis included history, signalment, physical examination findings, hematologic and serum biochemical data, presence of ketoacidosis, and diagnosis of concurrent diseases at initial evaluation. The effects of possible predictors on survival time were determined by calculating hazard ratios (HRs) and 95% confidence intervals (CIs).

Results—Median survival time of diabetic cats was 516 days (range, 1 to 3,468 days); 70%, 64%, and 46% lived longer than 3, 6, and 24 months, respectively. Survival time was significantly shorter for cats with higher creatinine concentrations, with a hazard of dying approximately 5% greater for each increase of 10 μg/dL in serum creatinine concentration (adjusted HR, 1.005; 95% CI, 1.003 to 1.007). Ketoacidosis was not significantly associated with survival time (HR, 1.02; 95% CI, 0.590 to 1.78).

Conclusions and Clinical Relevance—Cats with newly diagnosed diabetes mellitus had a fair to good prognosis. High serum creatinine concentration at diagnosis was associated with a poor outcome, likely because of the adverse effects of renal dysfunction. Ketoacidosis apparently was not associated with decreased survival time, suggesting that this complication should not necessarily be regarded as unfavorable.

Abstract

Objective—To evaluate 4 methods used to measure plasma insulin-like growth factor (IGF) 1 concentrations in healthy cats and cats with diabetes mellitus or other diseases.

Animals—39 healthy cats, 7 cats with diabetes mellitus, and 33 cats with other diseases.

Procedures—4 assays preceded by different sample preparation methods were evaluated, including acid chromatography followed by radioimmunoassay (AC-RIA), acid-ethanol extraction followed by immunoradiometry assay (AEE-IRMA), acidification followed by immunochemiluminescence assay (A-ICMA), and IGF-2 excess followed by RIA (IE-RIA). Validation of the methods included determination of precision, accuracy, and recovery. The concentration of IGF-1 was measured with all methods, and results were compared among cat groups.

Results—The intra-assay coefficient of variation was < 10% for AC-RIA, A-ICMA, and AEE-IRMA and 14% to 22% for IE-RIA. The linearity of dilution was close to 1 for each method. Recovery rates ranged from 69% to 119%. Five healthy cats had IGF-1 concentrations > 1,000 ng/mLwith the AEE-IRMA, but < 1,000 ng/mL with the other methods. Compared with healthy cats, hyperthyroid cats had significantly higher concentrations of IGF-1 with the A-ICMA method, but lower concentrations with the IE-RIA method. Cats with lymphoma had lower IGF-1 concentrations than did healthy cats regardless of the method used.

Conclusions and Clinical Relevance—Differences in the methodologies of assays for IGF-1 may explain, at least in part, the conflicting results previously reported in diabetic cats. Disorders such as hyperthyroidism and lymphoma affected IGF-1 concentrations, making interpretation of results more difficult if these conditions are present in cats with diabetes mellitus.

Abstract

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.