Search Results

Abstract

Objective—To investigate the effects of benazepril and heparin on renal function and blood pressure in dogs with chronic kidney disease.

Design—Randomized controlled clinical trial.

Animals—26 dogs with chronic kidney disease.

Procedures—Dogs were randomly assigned to receive benazepril hydrochloride (0.5 mg/kg [0.23 mg/lb], PO, q 24 h; n = 10), benazepril and heparin (150 U/kg [68 U/lb], SC, q 8 h, for the first 6 days; 10), or a placebo (6) and were followed up for 180 days.

Results—Health status score at the end of the study (ie, day 180) was significantly higher for dogs in the 2 treatment groups than for dogs in the placebo group. In addition, glomerular filtration rate was significantly increased and the urine protein-to-creatinine ratio was significantly decreased, compared with baseline rates, at the end of the study for dogs in both treatment groups but not for dogs in the placebo group. Systolic and diastolic blood pressures were significantly decreased on day 6 for dogs in both treatment groups.

Conclusions and Clinical Relevance—Results suggested that administration of benazepril had beneficial effects in dogs with chronic kidney disease but that short-term administration of heparin in conjunction with benazepril did not appear to provide any additional benefit.

Abstract

Objective—To evaluate the accuracy and reproducibility of left ventricular (LV) volumetric and function variables determined via contrast-enhanced cardiac CT and cardiac MRI in healthy dogs.

Animals—10 healthy Beagles.

Procedures—Cardiac MRI and cardiac CT were performed in anesthetized Beagles; both examinations were conducted within a 2-hour period. Cardiac MRI was performed with a 3.0-T magnet, and contrast-enhanced cardiac CT was performed with a 64-row detector CT machine. Data sets were acquired during apnea with simultaneous ECG gating. Short-axis images were created to determine functional variables via the Simpson method.

Results—Cardiac CT values for mean end-diastolic and end-systolic LV volumes had excellent correlation (r = 0.95) with cardiac MRI measurements, whereas LV stroke volume (r = 0.67) and LV ejection fraction (r = 0.75) had good correlations. The only variable that differed significantly between imaging modalities was end-diastolic LV volume. For each pair of values, Bland-Altman analysis revealed good limits of agreement.

Conclusions and Clinical Relevance—The 3-D modalities cardiac CT and cardiac MRI were excellent techniques for use in assessing LV functional variables. Similar results were obtained for LV volume and function variables via both techniques. The major disadvantage of these modalities was the need to anesthetize the dogs for the examinations.

Abstract

Objective—To evaluate the use of retrospectively ECG-gated, contrast-enhanced, multi-detector row computed tomography (MDCT) for assessment of left ventricular function in dogs and to compare the results with those obtained by use of 2-D and M-mode echocardiographc techniques.

Animals—10 healthy Beagles.

Procedures—Dogs underwent MDCT (performed by use of a 64-detector row CT system) and echocardiography under general anesthesia. Left ventricular end-systolic volume (ESV), end-diastolic volume (EDV), and ejection fraction (EF) were determined in MDCT-generated multiplanar reformatted images by use of Simpson and biplane area-length calculation methods. Results were compared with left ventricular ESV, EDV, and EF determined in echocardiographc images by use of Teichholz and bullet method calculations. Results were evaluated via Deming regression analysis and Pearson correlation tests. Bland-Altman analysis was used to assess limits of agreement and systematic errors between the 2 methods.

Results—Mean values for EDV and ESV determined by use of MDCT were highly correlated with those determined by use of echocardiography, regardless of the calculation methods compared (r = 0.91 to 0.96); volumes determined by use of MDCT appeared to be higher than those determined by use of echocardiography, although most differences were nonsignificant. Mean EF determined by use of MDCT with the Simpson calculation method was highly correlated with that determined by use of echocardiography with bullet method calculations (r = 0.90).

Conclusions and Clinical Relevance—Results suggested that assessment of left ventricular volume and function in dogs is feasible with MDCT. To estimate left ventricular EF with MDCT. use of the Simpson calculation method is advised.

Abstract

Objective—To determine whether plasma N-terminal proatrial natriuretic peptide (Nt-proANP) concentrations in cats with cardiomyopathy (CM) differ from values in healthy cats and evaluate whether plasma Nt-proANP concentrations can be used to discriminate cats with CM and congestive heart failure (CHF) from CM-affected cats without CHF.

Animals—16 cats that had CM without CHF, 16 cats that had CM with CHF, and 11 healthy control cats.

Procedures—All cats underwent a physical examination, assessment of clinicopathologic variables (including plasma thyroxine concentration), thoracic radiography, and echocardiography. On the basis of findings, cats were assigned to 1 of 3 groups (control cats, cats with CM and CHF, and cats with CM without CHF). Venous blood samples were obtained from all 43 cats, and plasma Nt-proANP concentrations were measured by use of a human proANP(1-98) ELISA.

Results—Plasma Nt-proANP concentrations differed significantly among the 3 groups. Median Nt-proANP concentration was 381 fmol/mL (range, 52 to 450 fmol/mL), 763 fmol/mL (range, 167 to 2,386 fmol/mL), and 2,443 fmol/mL (range, 1,189 to 15,462 fmol/mL) in the control group, in cats with CM without CHF, and in cats with CM and CHF, respectively.

Conclusions and Clinical Relevance—Measurement of plasma Nt-proANP concentration could be of benefit in the assessment of cats with naturally occurring CM and might have potential as a screening marker for the disease. Furthermore, measurement of plasma NtproANP concentration may be useful for distinguishing cats with CM and CHF from those with CM and no CHF.

Abstract

Objective—To evaluate effects of preoperative administration of carprofen on renal function and hemostasis in dogs undergoing general anesthesia for fracture repair.

Animals—26 client-owned dogs.

Procedure—Anesthesia was induced with levomethadone, diazepam, and propofol and maintained by administration of isoflurane in oxygen-nitrous oxide. Carprofen (4 mg/kg, SC) was administered 1 hour before induction to 13 dogs (group 1) and after extubation to the other 13 dogs (group 2). All dogs also received carprofen (4 mg/kg, SC, q 24 h) for the first 4 days after surgery. Renal function (glomerular filtration rate [GFR], urinary protein-to-urinary creatinine ratio [UP:UC], and results of urinalysis and biochemical analysis of plasma), hemostatic variables (bleeding time, platelet aggregation, prothrombin time [PT], activated partial thromboplastin time [APTT], and platelet count), and Hct were assessed before and at various time points after surgery.

Results—Analysis of results for renal function tests, most of the hemostatic and plasma biochemical variables, and Hct did not reveal significant differences between treatment groups. Values for GFR, UP:UC, PT, APTT, and platelet aggregation were outside reference ranges in many dogs before surgery and during the first 6 hours after surgery. In most dogs, these trauma-induced pathologic changes returned to within reference ranges during the 4-day period after surgery.

Conclusions and Clinical Relevance—Carprofen did not cause clinically relevant adverse effects in dogs anesthetized for fracture repair after 5 days of treatment, even when it was administered before surgery or given to patients with trauma-induced alterations in renal function or hemostasis. (Am J Vet Res 2005;66:1356–1363)

Abstract

Objective—To quantify left ventricle (LV) volumes by use of 1-D, 2-D, and 3-D echocardiography versus MRI in dogs.

Animals—10 healthy Beagles.

Procedures—During anesthesia, each dog underwent an echocardiographic examination via the Teichholz method, performed on the basis of standard M-mode frames (1-D); the monoplane Simpson method of disk (via 2-D loops); real-time triplane echocardiography (RTTPE) with a 3-D probe; and real-time 3-D echocardiography with a 3-D probe. Afterward, cardiac MRI was performed. Values for the LV end-diastolic volume (EDV), end-systolic volume (ESV), and ejection fraction (EF) were compared between each echocardiographic method and the reference method (cardiac MRI).

Results—No significant differences for EDV, ESV, and EF were detected between RTTPE and cardiac MRI. Excellent correlations (r = 0.97, 0.98, and 0.95 for EDV, ESV, and EF, respectively) were found between RTTPE and values for cardiac MRI. The other echocardiographic methods yielded values significantly different from cardiac MRI and results correlated less well with results of cardiac MRI for EDV, ESV, and EF. Use of the Teichholz method resulted in LV volume overestimation, whereas the Simpson method of disk and real-time 3-D echocardiography significantly underestimated LV volumes.

Conclusions and Clinical Relevance—Use of RTTPE yielded excellent correlations and nonsignificant differences with cardiac MRI and is a suitable method for routine veterinary cardiac examination.

Abstract

Objective—To determine the 50% inhibitory concentration (IC-50) of carboplatin, cisplatin, and doxorubicin in cell cultures of mammary gland tumors obtained from dogs and to assess whether in vitro efficacy was within the range of clinically relevant concentrations.

Sample Population—30 mammary gland tumors excised from dogs.

Procedure—Cell cultures were established from the 30 tumors. Cultures then were treated with carboplatin, cisplatin, or doxorubicin. Growth inhibition of cultures was assessed via DNA measurement 24, 48, and 72 hours after treatment. The IC-50 values were calculated by use of linear interpolation.

Results—Cultures varied in their pattern of susceptibility. Doxorubicin induced significantly lower IC-50 values than the platinum derivatives. Cisplatin and carboplatin had comparable effects. The IC-50 values for carboplatin and doxorubicin were in the range of clinically relevant concentrations, but only part of the cisplatin cultures had IC-50 values within clinically relevant concentrations. We did not detect differences in the in vitro susceptibility among subtypes of tumors (ie, adenocarcinoma, solid carcinoma, malignant mixed tumor).

Conclusion and Clinical Relevance—The IC-50 values determined in this study allowed assessment of in vitro drug efficacy of chemotherapeutics in cultures of mammary gland tumors obtained from dogs. Variations in susceptibility were evident and emphasize the importance of assessing susceptibility and resistance patterns for each tumor. Prospective studies to assess direct correlations between in vitro and in vivo efficacy must be performed to determine the clinical predictive value of this in vitro chemosensitivity assay for treatment of dogs with mammary gland tumors. (Am J Vet Res 2001;62:1825–1830)

Abstract

Objective—To determine whether plasma N-terminal proatrial natriuretic peptide (NT-proANP) concentration could predict the outcome (survival duration) of cats with cardiomyopathy (CM).

Design—Case-control study.

Animals—51 cats with CM (25 with and 26 without congestive heart failure [CHF]) and 17 healthy cats.

Procedures—Cats were thoroughly examined and assigned to 1 of 3 groups (control, CM with CHF, and CM alone). Plasma NT-proANP concentrations were measured by use of a human proANP(1-98) ELISA. Survival durations were compared between CM groups.

Results—Plasma NT-proANP concentrations differed significantly among the 3 groups, and survival durations differed significantly between the 2 CM groups. Median (range) NT-proANP concentration was 413 fmol/mL (52 to 940 fmol/mL) in the control group, 1,254 fmol/mL (167 to 2,818 fmol/mL) in the CM alone group, and 3,208 fmol/mL (1,189 to 15,462 fmol/mL) in the CM with CHF group. At a cutoff of 517 fmol/mL, NT-proANP concentration had a sensitivity of 90% and specificity of 82% for detecting CM. Multivariate analysis revealed that only the variable left atrium-to-aortic diameter ratio was a significant predictor of survival duration.

Conclusions and Clinical Relevance—Plasma NT-proANP concentration may have potential as a testing marker for distinguishing healthy cats from cats with CM. It may also be useful for distinguishing CM cats with CHF from those without CHF The value of NT-proANP concentration as a predictor of survival duration was not supported in this study and requires further evaluation. (J Am Vet Med Assoc 2010;237:665-672)

Abstract

Objective—To evaluate the load redistribution mechanisms in walking and trotting dogs with induced forelimb lameness.

Animals—7 healthy adult Beagles.

Procedures—Dogs walked and trotted on an instrumented treadmill to determine control values for peak and mean vertical force as well as verticle impulse for all 4 limbs. A small sphere was attached to the ventral pad of the right forelimb paw to induce a reversible lameness, and recordings were repeated for both gaits. Additionally, footfall patterns were assessed to test for changes in temporal gait variables.

Results—During walking and trotting, peak and mean vertical force as well as vertical impulse were decreased in the ipsilateral forelimb, increased in the contralateral hind limb, and remained unchanged in the ipsilateral hind limb after lameness was induced. All 3 variables were increased in the contralateral forelimb during trotting, whereas only mean vertical force and vertical impulse were increased during walking. Stance phase duration increased in the contralateral forelimb and hind limb during walking but not during trotting.

Conclusions and Clinical Relevance—Analysis of the results suggested that compensatory load redistribution mechanisms in dogs depend on the gait. All 4 limbs should be evaluated in basic research and clinical studies to determine the effects of lameness on the entire body. Further studies are necessary to elucidate specific mechanisms for unloading of the affected limb and to determine the long-term effects of load changes in animals with chronic lameness.

Abstract

Objective—To determine whether the extent of disease in dogs with lymphoma can be assessed via flow cytometry and to evaluate the suitability of fine-needle aspirates from the liver and spleen of dogs for flow cytometric examination.

Animals—44 dogs with multicentric B-cell (n = 35) or T-cell lymphoma (9) and 5 healthy control dogs.

Procedures—Peripheral blood and bone marrow samples and fine-needle aspirates of lymph node, liver, and spleen were examined via flow cytometry. Logarithmically transformed T-cell–to–B-cell percentage ratio (log[T:B]) values were calculated. Thresholds defined by use of log(T:B) values of samples from control dogs were used to determine extranodal lymphoma involvement in lymphoma-affected dogs; results were compared with cytologic findings.

Results—12 of 245 (5%) samples (9 liver, 1 spleen, and 2 bone marrow) had insufficient cellularity for flow cytometric evaluation. Mean log(T:B) values of samples from dogs with B-cell lymphoma were significantly lower than those of samples from the same site in dogs with T-cell lymphoma and in control dogs. In dogs with T-cell lymphoma, the log(T:B) of lymph node, bone marrow, and spleen samples was significantly higher than in control dogs. Of 165 samples assessed for extranodal lymphoma involvement, 116 (70%) tested positive via flow cytometric analysis; results agreed with cytologic findings in 133 of 161 (83%) samples evaluated via both methods.

Conclusions and Clinical Relevance—Results suggested that flow cytometry may aid in detection of extranodal lymphoma involvement in dogs, but further research is needed. Most fine-needle aspirates of liver and spleen were suitable for flow cytometric evaluation.