Comparison of three staining methods to identify eosinophils in formalin-fixed canine skin.

BACKGROUND: Studies comparing the ability of staining methods to detect eosinophils in formalin-fixed canine skin are lacking. HYPOTHESIS/OBJECTIVES: The aim of this study was to compare the effectiveness of eosinophil peroxidase monoclonal antibody (EPXmAb), Luna and haematoxylin and eosin (H&E) to detect eosinophils in fixed canine skin by assessing the following parameters: (i) specificity of eosinophil staining; (ii) extracellular eosinophil granule staining; (iii) tissue background staining; (iv) contrast between eosinophil and surrounding tissue staining; and (v) differences in the number of eosinophils detected by each stain. METHODS: Three serial sections of formalin-fixed, paraffin-embedded tissues of predominantly eosinophilic skin diseases (n = 8), noneosinophilic skin diseases (n = 7) and normal canine skin (n = 1) were stained with the three stains. Each parameter was independently assessed and scored by two investigators. RESULTS: Luna and EPXmAb were specific in detecting eosinophils. The EPXmAb was significantly more effective than Luna (P < 0.001) and H&E (P < 0.001) in its ability to detect extracellular eosinophil granules (i.e. to detect intact and released eosinophil granules). The EPXmAb showed significantly less background staining compared with Luna (P = 0.0005). Moreover, significantly more stain contrast was noted with EPXmAb compared with Luna (P = 0.003) and H&E (P < 0.001). There was no significant difference between the mean eosinophil counts among the three stains. CONCLUSION AND CLINICAL IMPORTANCE: The three stains were shown to be useful to detect and quantify eosinophils in fixed canine skin. The EPXmAb-based immunohistochemical stain proved to be a novel tool to detect eosinophils in canine skin.

Ultrasound criteria and guided fine-needle aspiration diagnostic yields in small animal peritoneal, mesenteric and omental disease.

Peritoneal, mesenteric, and omental diseases are important causes of morbidity and mortality in humans and animals, although information in the veterinary literature is limited. The purposes of this retrospective study were to determine whether objectively applied ultrasound interpretive criteria are statistically useful in differentiating among cytologically defined normal, inflammatory, and neoplastic peritoneal conditions in dogs and cats. A second goal was to determine the cytologically interpretable yield on ultrasound-guided, fine-needle sampling of peritoneal, mesenteric, or omental structures. Sonographic criteria agreed upon by the authors were retrospectively and independently applied by two radiologists to the available ultrasound images without knowledge of the cytologic diagnosis and statistically compared to the ultrasound-guided, fine-needle aspiration cytologic interpretations. A total of 72 dogs and 49 cats with abdominal peritoneal, mesenteric, or omental (peritoneal) surface or effusive disease and 17 dogs and 3 cats with no cytologic evidence of inflammation or neoplasia were included. The optimized, ultrasound criteria-based statistical model created independently for each radiologist yielded an equation-based diagnostic category placement accuracy of 63.2-69.9% across the two involved radiologists. Regional organ-associated masses or nodules as well as aggregated bowel and peritoneal thickening were more associated with peritoneal neoplasia whereas localized, severely complex fluid collections were more associated with inflammatory peritoneal disease. The cytologically interpretable yield for ultrasound-guided fine-needle sampling was 72.3% with no difference between species, making this a worthwhile clinical procedure.

Clinical, ultrasonographic, and laboratory findings associated with gallbladder disease and rupture in dogs: 45 cases (1997-2007).

OBJECTIVE: To identify clinical, laboratory, and ultrasonographic characteristics associated with gallbladder disease and rupture in dogs. DESIGN: Retrospective case series. ANIMALS: 45 client-owned dogs. PROCEDURES: Medical records of dogs with histologically confirmed gallbladder disease that had ultrasonographic evaluation were reviewed. Signalment, history, clinical signs, laboratory values, bacteriologic culture of bile, gallbladder status at surgery or necropsy (intact vs ruptured), histopathologic findings, radiographic findings, ultrasonographic findings, and outcome were analyzed. RESULTS: The most common ultrasonographic findings were echogenic peritoneal fluid, thickened or laminated gallbladder wall, and echogenic reaction in the gallbladder fossa. Eighteen of 45 (40%) dogs had gallbladder rupture. Rupture was associated with histologic evidence of gallbladder necrosis, decreased serosal detail radiographically, and pericholecystic echogenic reaction, pericholecystic echogenic fluid, and generalized echogenic abdominal effusion ultrasonographically. Twenty-one of 45 (47%) dogs had mucocele, and 9 (43%) of those had gallbladder rupture. Eleven of 40 dogs had positive results of bacteriologic culture, and 5 of those had gallbladder rupture. Only 2 dogs had concurrent positive results of bacterial bile culture and gallbladder mucocele. Survival rate was 86% and not significantly related to presurgical bile leakage, positive results of bacterial culture, or mucocele. CONCLUSIONS AND CLINICAL RELEVANCE: Ultrasonographic findings of pericholecystic reaction, localized or generalized echogenic peritoneal fluid, or decreased radiographic peritoneal detail should raise the index of suspicion for gallbladder rupture. Mucocele or bacterial gallbladder infection was the most common concurrent finding in dogs with gallbladder rupture.

Evaluation of diffusion-weighted magnetic resonance imaging at 3.0 Tesla for differentiation between intracranial neoplastic and noninfectious inflammatory lesions in dogs.

OBJECTIVE: To evaluate the utility of apparent diffusion coefficient (ADC) and fractional anisotropy (FA) values obtained by diffusion-weighted MRI (DWI) at 3.0 T for differentiating intracranial neoplastic lesions from noninfectious inflammatory lesions (NIILs) in dogs. ANIMALS: 54 dogs that met inclusion criteria (ie, had a histologically confirmed intracranial lesion and DWI of the brain performed) with 5 lesion types: meningioma [n = 18], glioma [14], metastatic hemangiosarcoma [3], other metastatic neoplasms [5], and NIIL [14]). PROCEDURES: Two observers, who were blinded to the histologic diagnoses, independently determined the mean ADC and FA values for each evaluated intracranial lesion on the basis of 3 circular regions of interest on DWI images. Findings were compared among the 5 lesion types, between all neoplasms combined and NIILs, and between the 5 legion types and previously determined values for corresponding locations for neurologically normal dogs. RESULTS: The mean ADC and FA values did not differ significantly among the 5 lesion types or between all neoplasms combined and NIILs. However, 35% (14/40) of the neoplastic lesions had an ADC value ≥ 1.443 × 10-3 mm2/s, whereas all NIILs had ADC values < 1.443 × 10-3 mm2/s. Meningiomas and NIILs had FA values that were significantly lower than those for neurologically normal dogs. CONCLUSIONS AND CLINICAL RELEVANCE: In this population of dogs, the FA values for meningiomas and NIILs differed significantly from those previously reported for neurologically normal dogs. In addition, an ADC cutoff value of 1.443 × 10-3 mm2/s appeared to be highly specific for diagnosing neoplastic lesions (vs NIILs), although the sensitivity and accuracy were low.

Statistical relevance of ultrasonographic criteria in the assessment of diffuse liver disease in dogs and cats.

OBJECTIVE: To determine whether objectively applied ultrasonographic interpretive criteria are statistically useful in differentiating among 7 defined categories of diffuse liver disease in dogs and cats. SAMPLE POPULATION: Ultrasonographic images of 229 dogs and 104 cats. PROCEDURES: Liver parenchymal or related sonographic criteria established by the authors were retrospectively and independently applied by 3 radiologists who were not aware of patient status or patient laboratory data. Seven histologic or cytologic categories of diffuse (infiltrative but not nodular) liver diseases were jointly established by the authors and included normal liver; inflammation; round-cell neoplasia; non-round-cell infiltrative, prenodular (early) metastatic neoplasia; lipidosis; vacuolar hepatopathy; and other. Liver parenchymal sonographic criteria included parenchymal sound attenuation with increasing depth, comparative organ echogenicity (liver, spleen, and kidneys), diffuse or patchy hyperechoic or hypoechoic echotexture, uniform or coarse echotexture, portal venous clarity, and liver lobe geometry. Related extrahepatic criteria included gallbladder wall thickness, bile duct diameter, amount and character of gallbladder precipitate, nondependent shadowing in the gallbladder, hepatic vein diameter versus caudal vena cava diameter, peritoneal fluid, spleen echotexture (normal vs abnormal [characterized]), and kidney echotexture. Ultrasonographic criteria were statistically compared to the 7 categories of diffuse liver disease in search of clinically exploitable relationships. RESULTS: Statistical evaluation of the applied ultrasonographic criteria did not yield clinically acceptable accuracy for discrimination among the 7 categories of diffuse liver diseases (including normal liver) in either species. CONCLUSIONS AND CLINICAL RELEVANCE: Criterion-based ultrasonographic appearance was insufficient to discriminate among canine and feline diffuse infiltrative liver diseases.

Radiographic findings in dogs with pulmonary blastomycosis: 125 cases (1989-2006).

OBJECTIVE: To identify radiographic patterns in dogs with pulmonary blastomycosis and radiographic factors associated with outcome. DESIGN: Retrospective case series. ANIMALS: 125 dogs with pulmonary blastomycosis. PROCEDURES: Medical records were reviewed, and for each lung lobe, the primary radiographic pattern and percentage of lobar involvement at the time of initial examination were recorded. RESULTS: 79 dogs survived, 38 died, and 8 were euthanized without treatment. The initial radiographic pattern was variable and not significantly associated with outcome. Mean half-time for radiographic resolution of pulmonary infiltrates was 41.4 days for all patterns except masses, for which mean half-time to resolution was 90.8 days. Transient radiographic worsening was seen in 20 of 87 (23%) dogs but was not associated with a poor prognosis. Pulmonary bullae were seen in 20 (16%) dogs, most often in association with an alveolar pattern. Accuracy of using percentage of right caudal lung lobe involvement ( 20%) to predict outcome was 74.4%; accuracy of using number of affected lobes (< 4 vs >or= 4) to predict outcome was 65.8%. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that a nonuniform distribution of pulmonary infiltrates was equally as likely as a diffuse nodular interstitial pattern in dogs with pulmonary blastomycosis. On the basis of half-time for resolution of pulmonary infiltrates, follow-up radiography should be performed no more often than every 4 to 6 weeks in clinically stable patients. Transient radiographic worsening that occurred during the initial weeks of treatment was not associated with a poorer prognosis.

Utility of diagnostic tests for and medical treatment of pulmonary blastomycosis in dogs: 125 cases (1989-2006).

OBJECTIVE: To compare results of the most common diagnostic tests for pulmonary blastomycosis in dogs, identify factors associated with outcome, and determine response to various antifungal treatment protocols. DESIGN: Retrospective case series. ANIMALS: 125 dogs with pulmonary blastomycosis. PROCEDURES: Medical records were reviewed, and information was obtained regarding diagnostic methods, results of routine laboratory testing, and radiographic response to antifungal treatment. RESULTS: 79 dogs survived, 38 died, and 8 were euthanized. Transthoracic fine-needle aspiration and transtracheal lavage were the most common diagnostic methods. Results of an agar gel immunodiffusion test for antibodies against Blastomyces dermatitidis were negative in 12 of 24 (50%) dogs. Only 3 of 94 (3.2%) dogs in which cytologic or histologic examination or bacterial culture of pulmonary samples were performed had any evidence of concurrent bacterial infection. The half-time for radiographic resolution of pulmonary infiltrates did not vary significantly with antifungal treatment, and use of a loading dosage of itraconazole was not associated with significant improvements in outcome or time to disease resolution. Dogs that died had a higher number of band neutrophils at initial examination, compared with those that survived. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that the agar gel immunodiffusion test should not be used as the sole diagnostic test for pulmonary blastomycosis in dogs, that concurrent bacterial pneumonia was uncommon in dogs with pulmonary blastomycosis, and that the rate with which pulmonary infiltrates resolved did not vary significantly among antifungal treatments.

Evaluation of the diagnostic utility of cytologic examination of renal fine-needle aspirates from dogs and the use of ultrasonographic features to inform cytologic diagnosis.

OBJECTIVE To describe cytologic characteristics of renal fine-needle aspirate (FNA) samples from dogs, evaluate proportions of cytologic specimens deemed adequate for interpretation (diagnostic yield), assess diagnostic utility of cytologic examination for neoplastic and nonneoplastic diseases, and characterize ultrasonographic features of evaluated kidneys to determine whether the imaging characteristics could be used to inform cytologic interpretations. DESIGN Retrospective, observational study. SAMPLE 102 cytologic specimens and 97 ultrasonographic studies from 100 dogs. PROCEDURES Medical records were reviewed to identify dogs that underwent ultrasound-guided renal FNA. Slides were categorized as adequate or inadequate for interpretation; adequate slides were used for retrospective cytologic diagnosis. Sensitivity, specificity, and predictive values of cytologic examination for detection of neoplastic and nonneoplastic conditions were calculated by comparison with histologic or lymphoid cell clonality assay results. Ultrasonographic characteristics of neoplastic and nonneoplastic renal lesions were described. RESULTS 74 of 102 (72%) specimens had slides adequate for interpretation; 26 were included in the diagnostic accuracy analysis. Sensitivity of cytologic examination was 78% and 50% for detection of neoplastic and nonneoplastic conditions, respectively, with specificities of 50% and 77%, respectively; sensitivity for detection of lymphoma was 100%. Ultrasonographic appearance of kidneys with confirmed neoplasia varied; masses were most commonly found in kidneys with carcinoma (5/5), lymphoma (5/7), or other neoplasia (3/4) and absent in kidneys with nonneoplastic conditions (n = 5). CONCLUSIONS AND CLINICAL RELEVANCE Renal FNA specimens were adequate for interpretation at rates comparable with those reported for other organs and were considered clinically useful for diagnosis of neoplasia. Imaging characteristics may potentially aid differentiation between neoplastic and nonneoplastic lesions; however, further investigation is needed.

Evaluation of total and ionized calcium status in dogs with blastomycosis: 38 cases (1997-2006).

OBJECTIVE: To determine blood ionized calcium (iCa) and serum total calcium (tCa) concentrations in dogs with blastomycosis and to evaluate whether serum tCa concentration, albumin-adjusted serum calcium concentration (AdjCa-Alb), and total protein-adjusted serum calcium concentration (AdjCa-TP) accurately predict iCa status. DESIGN: Retrospective case series. ANIMALS: 38 client-owned dogs with a cytologic diagnosis of blastomycosis. PROCEDURES: Dogs were classified as hypocalcemic, normocalcemic, or hypercalcemic on the basis of blood iCa concentration, serum tCa concentration, AdjCa-Alb, and AdjCa-TP; classification on the basis of serum tCa concentration, AdjCa-Alb, and AdjCa-TP was compared with blood iCa concentration. RESULTS: Except for 2 hypercalcemic dogs, all dogs had blood iCa concentrations within the reference interval. Use of serum tCa concentration overestimated hypocalcemia in 57.9% (22/38) of dogs and underestimated hypercalcemia in 1 dog. Use of AdjCa-Alb correctly reclassified all dogs as normocalcemic that were classified as hypocalcemic on the basis of serum tCa concentration, but failed to predict hypercalcemia in 1 dog. Use of AdjCa-TP correctly reclassified all but 2 dogs as normocalcemic that were classified as hypocalcemic on the basis of serum tCa concentration, and failed to predict hypercalcemia in 1 dog. No correlation was found between blood iCa concentration and serum concentrations of tCa, total protein, and albumin; AdjCa-Alb; or AdjCa-TP. CONCLUSIONS AND CLINICAL RELEVANCE: High blood iCa concentration was uncommon in dogs with blastomycosis. Hypoalbuminemia contributed to a low serum tCa concentration despite a blood iCa concentration within reference limits. The use of serum tCa concentration, AdjCa-Alb, and AdjCa-TP may fail to identify a small number of dogs with high blood iCa concentrations.

Diffusion-weighted magnetic resonance imaging of the brain of neurologically normal dogs.

OBJECTIVE To acquire MRI diffusion data (apparent diffusion coefficient [ADC] and fractional anisotropy [FA] values, including separate measures for gray and white matter) at 3.0 T for multiple locations of the brain of neurologically normal dogs. ANIMALS: 13 neurologically normal dogs recruited from a group of patients undergoing tibial plateau leveling osteotomy. PROCEDURES: MRI duration ranged from 20 to 30 minutes, including obtaining preliminary images to exclude pathological changes (T2-weighted fluid-attenuated inversion recovery transverse and dorsal images) and diffusion-weighted images. , RESULTS: Globally, there were significant differences between mean values for gray and white matter in the cerebral lobes and cerebellum for ADC (range of means for gray matter, 0.8349 × 10-3 s/mm2 to 0.9273 × 10-3 s/mm2; range of means for white matter, 0.6897 × 10-3 s/mm2 to 0.7332 × 10-3 s/mm2) and FA (range of means for gray matter, 0.1978 to 0.2364; range of means for white matter, 0.5136 to 0.6144). These values also differed among cerebral lobes. In most areas, a positive correlation was detected between ADC values and patient age but not between FA values and patient age. CONCLUSIONS AND CLINICAL RELEVANCE: Cerebral interlobar and cerebellar diffusion values differed significantly, especially in the gray matter. Information about diffusion values in neurologically normal dogs may be used to diagnose and monitor abnormalities and was the first step in determining the clinical use of diffusion imaging. This information provided an important starting point for the clinical application of diffusion imaging of the canine brain.

Evaluation of canine hepatic masses by use of triphasic computed tomography and B-mode, color flow, power, and pulsed-wave Doppler ultrasonography and correlation with histopathologic classification.

OBJECTIVE To determine clinical relevance for quantitative and qualitative features of canine hepatic masses evaluated by use of triphasic CT and B-mode, color flow, power, and pulsed-wave Doppler ultrasonography and to compare diagnostic accuracy of these modalities for predicting mass type on the basis of histopathologic classification. ANIMALS 44 client-owned dogs. PROCEDURES Dogs with histopathologic confirmation (needle core, punch, or excisional biopsy) of a hepatic mass were enrolled. Triphasic CT and B-mode, color flow, power, and pulsed-wave Doppler ultrasonography of each hepatic mass were performed. Seventy quantitative and qualitative variables of each hepatic mass were recorded by 5 separate observers and statistically evaluated with discriminant and stepwise analyses. Significant variables were entered in equation-based predictions for the histopathologic diagnosis. RESULTS An equation that included the lowest delayed-phase absolute enhancement of the mass and the highest venous-phase mass conspicuity was used to correctly classify 43 of 46 (93.5%) hepatic masses as benign or malignant. An equation that included only the lowest delayed-phase absolute enhancement of the mass could be used to correctly classify 42 of 46 (91.3%) masses (with expectation of malignancy if this value was < 37 Hounsfield units). For ultrasonography, categorization of the masses with cavitations as malignant achieved a diagnostic accuracy of 80.4%. CONCLUSIONS AND CLINICAL RELEVANCE Triphasic CT had a higher accuracy than ultrasonography for use in predicting hepatic lesion classification. The lowest delayed-phase absolute enhancement of the mass was a simple calculation that required 2 measurements and aided in the differentiation of benign versus malignant hepatic masses.

Disseminated intravascular coagulation in cats.

The purpose of this study was to describe the clinical characteristics of cats with disseminated intravascular coagulation (DIC), including associated diseases and hemostatic abnormalities, and to identify risk factors for death and treatments that potentially altered outcome. Medical records for cats with DIC from 1990-2004 were evaluated retrospectively. Inclusion criteria were the presence of an underlying disorder associated with DIC and either postmortem examination findings of intravascular fibrin deposition or thrombosis, or both of 2 or more organs or coagulation profiles that meet 3 of 5 criteria: prolonged prothrombin time (PT), activated partial thromboplastin time (aPTT), presence of fibrin degradation products (FDP), low plasma fibrinogen (FIB) concentration, and thrombocytopenia (<160,000 platelets/microL). Signalment, historical data, clinical findings, clinicopathologic data, underlying disorders, management, and outcome were recorded. Forty-six cats fulfilled the criteria for DIC. Cats ranged in age from 7 weeks to 17 years (median, 9 years). Hemorrhage was noted in 7 of 46 cats (15%). Three of 46 cats (7%) survived, whereas 43 of 46 (93%) died or were euthanized. The most common underlying disorders were lymphoma, other forms of neoplasia, pancreatitis, and sepsis. There was no association detected between outcome and signalment; underlying disease; hemorrhage; abnormalities in aPTT, FIB, FDPs, platelet count; transfusion of blood products; and heparin therapy. However, the median PT of nonsurvivors was more prolonged than in survivors (P < .005). DIC in cats can result from a variety of neoplastic, infectious, and inflammatory disorders, and is associated with a high case fatality rate.

Sequential measurements of the tibial plateau angle in large-breed, growing dogs.

OBJECTIVES: To determine the earliest age that canine tibial plateau angles (TPAs) can be reliably measured and determine whether TPAs change during long bone growth. ANIMALS: 10 Labrador Retrievers and 20 Labrador Retriever-hound crossbreeds. PROCEDURE: Stifle joints were radiographed every 2 months from 8 weeks of age to radiographic closure of the tibial physes. Four examiners radiographically evaluated TPA, physeal closure status (ie, complete or incomplete) of the proximal and distal tibial physis, and whether anatomic TPA measurement landmarks were sufficiently visible (LSV) or insufficiently visible (LIV) for accurate measuring. Linear regression analysis was performed to detect change in TPAs over time. Mean ages with 95% confidence intervals (CIs) were determined for dogs with radiographs classified as LIV and LSV. RESULTS: TPAs did not change from 90 days of age to physeal closure. Mean age for dogs with radiographs classified as LIV was 70.2 days (95% CI, 68.12 to 72.28 days), with no dog with LIV radiographs over 81 days of age. Mean age for dogs with radiographs classified as LSV was 85.5 days (CI, 76.73 to 94.27 days). CONCLUSIONS AND CLINICAL RELEVANCE: TPAs in Labrador Retrievers and Labrador Retriever-hound crossbreeds can be measured accurately after 90 days of age, and earlier attempts to measure result in falsely low TPA measurements. Measuring TPAs in growing dogs may allow earlier detection of premature physeal closures. As more is learned about the role of theTPA in cranial cruciate ligament injury, early treatment may be possible for growing dogs with cruciate ligament injuries and excessive tibial slope.

Evaluation of relationships between pretreatment patient variables and duration of isolation for radioiodine-treated hyperthyroid cats.

OBJECTIVE: To determine relationships between commonly measured pretreatment variables and duration of isolation for unrestricted dismissal after oral administration of iodine 131 (131I) for treatment of hyperthyroidism in cats. ANIMALS: 149 hyperthyroid cats treated with 131I. PROCEDURE: A dose of 131I (2.9 to 6.04 mCi [1.07 to 2.23 x 10(8) Bq]) was administered orally to all cats after hyperthyroidism was confirmed by evaluation of serum total thyroxine (T4) concentrations. Forward stepwise regression analysis was used to determine whether pretreatment total T4 concentration, serum creatinine concentration, body weight, age, 131I dose, or concurrent administration of cardiac medication (specifically excluding thyroid suppression drugs) could be used as pretreatment predictors of duration of isolation in a clinical setting. Gamma radiation emission rate at dismissal was < 2.0 mR/h at skin surface over the thyroid region. RESULTS: Mean +/- SD duration of isolation was 16.67 +/- 4.42 days (95% confidence interval, 9.2 to 24.1 days). The regression equation for duration of isolation calculated on the basis of dose of 131I (duration of isolation [days] = 3.2 + [2.66 X mCi - 131I dose]) yielded a regression line with a 95% confidence interval of +/- 3.3 days; only 15% of the variation was explained. CONCLUSIONS AND CLINICAL RELEVANCE: A pretreatment estimate for duration of isolation could be determined only from an equation based on the orally administered dose of 131I. These findings suggest that administration of the lowest efficacious dose possible is the dominant factor in reduction of duration of isolation for cats treated with 131I.

Relationship between orally administered dose, surface emission rate for gamma radiation, and urine radioactivity in radioiodine-treated hyperthyroid cats.

OBJECTIVE: To determine the relationship between surface emission rate of gamma radiation and urine concentration of I131 (urine radioactivity) during the period 7 to 21 days after oral or SC administration of I131 to hyperthyroid cats. ANIMALS: 47 hyperthyroid cats administered I131 PO and 24 hyperthyroid cats administered I131 SC. PROCEDURE: A dose of I131 (1.78 to 2.04 X 10(2) MBq [4.8 to 5.5 mCi]) was administered orally. Surface emission at the skin adjacent to the thyroid gland on days 7, 10, 14, 18, and 21 and number of counts/30 s in a urine sample (1 mL, obtained via cystocentesis) on days 7, 14, and 21 after oral administration were measured. Effective half-life (T1/2E) was derived for each point. Surface emission thresholds for maximum urine radioactivity values were established. A dose of I131 (1.48 X 10(2) MBq [4.0 mCi]) was administered SC. Urine radioactivity and surface emission rates for SC administration were compared with values for oral administration. RESULTS: The T1/2E for surface emissions and urine radioactivity progressively increased toward values for physical T1/2 over time. The T1/2E for surface emissions was 2.19 to 4.70 days, and T1/2E for urine radioactivity was 2.16 to 3.67 days. Surface emission rates had a clinically useful threshold relationship to maximum urine concentrations of I131. CONCLUSIONS AND CLINICAL RELEVANCE: Surface emission rates for cats administered I131 appeared useful in determining upper limits (threshold) of urine radioactivity and are a valid method to assess the time at which cats can be discharged after I131 administration.

Risk factors for leakage following intestinal anastomosis in dogs and cats: 115 cases (1991-2000).

OBJECTIVE: To identify factors associated with leakage following intestinal anastomosis in dogs and cats. DESIGN: Retrospective study. ANIMALS: 90 dogs and 25 cats. PROCEDURE: Medical records of all dogs and cats that underwent intestinal resection and anastomosis between 1991 and 2000 were reviewed, and information on 27 factors was recorded. RESULTS: Anastomotic leakage was identified in 13 of the 90 dogs but in none of the 25 cats. Preoperative factors significantly associated with development of anastomotic leakage in dogs included preoperative peritonitis, serum albumin concentration, a left shift, and indication for surgery (dogs with intestinal foreign bodies were more likely to have leakage than dogs that underwent surgery for any other cause). Postoperative and case management factors significantly associated with development of leakage included duration of hospitalization, supplemental alimentation, whether the dog ate the day after surgery, blood product administration, and outcome (died vs survived). Discriminant analysis was performed, and dogs with 2 or more of the following factors were predicted to develop anastomotic leakage: preoperative peritonitis, intestinal foreign body, and serum albumin concentration < or = 2.5 g/dL. The model accurately predicted whether leakage would develop in 67 of 80 (84%) dogs. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that a variety of factors may be associated with development of intestinal anastomotic leakage in dogs. In particular, dogs with 2 or more of the following risk factors are predicted to be at high risk for developing anastomotic leakage: preoperative peritonitis, intestinal foreign body, and serum albumin concentration < or = 2.5 g/dL.

Surgical and postoperative complications associated with tibial plateau leveling osteotomy in dogs with cranial cruciate ligament rupture: 397 cases (1998-2001).

OBJECTIVE: To identify surgical and postoperative complications of tibial plateau leveling osteotomy (TPLO) in dogs with rupture of the cranial cruciate ligament (CCL) and compare their incidence with those reported in the literature for other commonly performed CCL stabilization procedures. DESIGN: Retrospective study. ANIMALS: 346 dogs undergoing 397 TPLO procedures. PROCEDURE: Medical records of dogs undergoing 563 consecutive TPLO procedures were reviewed. Complications were recorded and assigned to groups on the basis of the period during which the complication was observed. RESULTS: 397 TPLOs met the criteria for inclusion in the study. Complications (n = 136) were recorded in 113 of the 397 (28%) procedures. Multiple complications developed in 10 dogs. In 19 dogs, a second surgery was performed to manage complications. Development of a complication after surgery was not associated with age or body weight of the dog, tibial plateau angle prior to stifle joint surgery, or experience of the surgeon. Factors significantly associated with complications were breed and performance of an arthrotomy concomitantly with TPLO. CONCLUSIONS AND CLINICAL RELEVANCE: TPLO was associated with development of numerous complications, some of which required surgical correction. Most complications resolved with nonsurgical treatment. Several complications were unique to the TPLO procedure because of the surgical technique and implants required. Although TPLO was associated with a greater number of complications than other CCL stabilization methods, the incidence of major complications was similar.

Absolute and relative cell counts for synovial fluid from clinically normal shoulder and stifle joints in cats.

OBJECTIVE: To determine absolute and relative cell counts for synovial fluid from grossly, radiographically, and histologically normal shoulder and stifle joints in healthy cats. DESIGN: Clinical study. ANIMALS: 52 cats scheduled to be euthanatized for unrelated reasons. PROCEDURE: Arthrocentesis of the shoulder and stifle joints was performed bilaterally, and synovial fluid was analyzed for absolute WBC count, WBC morphology, and percentages of neutrophils and mononuclear cells. Joints were examined grossly and radiographically, and synovial membrane specimens were submitted for histologic examination. Synovial fluid samples that were contaminated with blood and samples from joints with any gross, radiographic, or histologic abnormalities were excluded. RESULTS: 82 of the 208 synovial fluid samples were excluded because abnormalities were identified during physical examination; the volume of fluid obtained was insufficient for analysis; there was evidence of blood contamination; or the joint had gross, radiographic, or histologic abnormalities. Median WBC count for the remaining 126 synovial fluid samples was 91 cells/microL (96.4% mononuclear cells and 3.6% neutrophils); WBC count was not significantly different between left and right joint samples or between shoulder and stifle joint samples. Body weight was associated with synovial fluid WBC count, with WBC count increasing as body weight increased. Sixteen of the 52 (30%) cats had radiographic evidence of osteoarthritis involving at least 1 joint. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that synovial fluid can be obtained reliably from shoulder and stifle joints in cats.

Multivoxel proton magnetic resonance spectroscopy of inflammatory and neoplastic lesions of the canine brain at 3.0 T.

OBJECTIVE: To describe findings of 3.0-T multivoxel proton magnetic resonance spectroscopy ((1)H-MRS) in dogs with inflammatory and neoplastic intracranial disease and to determine the applicability of (1)H-MRS for differentiating between inflammatory and neoplastic lesions and between meningiomas and gliomas. ANIMALS: 33 dogs with intracranial disease (19 neoplastic [10 meningioma, 7 glioma, and 2 other] and 14 inflammatory). PROCEDURES: 3.0-T multivoxel (1)H-MRS was performed on neoplastic or inflammatory intracranial lesions identified with conventional MRI. N-acetylaspartate (NAA), choline, and creatine concentrations were obtained retrospectively, and metabolite ratios were calculated. Values were compared for metabolites separately, between lesion categories (neoplastic or inflammatory), and between neoplastic lesion types (meningioma or glioma) by means of discriminant analysis and 1-way ANOVA. RESULTS: The NAA-to-choline ratio was 82.7% (62/75) accurate for differentiating neoplastic from inflammatory intracranial lesions. Adding the NAA-to-creatine ratio or choline-to-creatine ratio did not affect the accuracy of differentiation. Neoplastic lesions had lower NAA concentrations and higher choline concentrations than inflammatory lesions, resulting in a lower NAA-to-choline ratio, lower NAA-to-creatine ratio, and higher choline-to-creatine ratio for neoplasia relative to inflammation. No significant metabolite differences between meningiomas and gliomas were detected. CONCLUSIONS AND CLINICAL RELEVANCE: (1)H-MRS was effective for differentiating inflammatory lesions from neoplastic lesions. Metabolite alterations for (1)H-MRS in neoplasia and inflammation in dogs were similar to changes described for humans. Use of (1)H-MRS provided no additional information for differentiating between meningiomas and gliomas. Proton MRS may be a beneficial adjunct to conventional MRI in patients with high clinical suspicion of inflammatory or neoplastic intracranial lesions.

Optimizing a protocol for (1) H-magnetic resonance spectroscopy of the canine brain at 3T.

Intracranial diseases are common in dogs and improved noninvasive diagnostic tests are needed. Magnetic resonance (MR) spectroscopy is a technique used in conjunction with conventional MR imaging to characterize focal and diffuse pathology, especially in the brain. As with conventional MR imaging, there are numerous technical factors that must be considered to optimize image quality. This study was performed to develop an MR spectroscopy protocol for routine use in dogs undergoing MR imaging of the brain. Fifteen canine cadavers were used for protocol development. Technical factors evaluated included use of single-voxel or multivoxel acquisitions, manual placement of saturation bands, echo time (TE), phase- and frequency-encoding matrix size, radiofrequency coil, and placement of the volume of interest relative to the calvaria. Spectrum quality was found to be best when utilizing a multivoxel acquisition with the volume of interest placed entirely within the brain parenchyma without use of manually placed saturation bands, TE = 144 ms, and a quadrature extremity radiofrequency coil. An 18 × 18 phase- and frequency-encoding matrix size also proved optimal for image quality, specificity of voxel placement, and imaging time.