Diagnostic accuracy of brush cytology in canine chronic intranasal disease.

BACKGROUND: Most cases of canine chronic intranasal disease cannot be differentiated based on clinical examination alone, and biopsy is often required for a definitive diagnosis. Nonsurgical cytologic and histologic biopsy techniques represent desirable diagnostic approaches. OBJECTIVE: The aim of this retrospective study was to determine the diagnostic accuracy of brush cytology in differentiating non-neoplastic and neoplastic diseases in dogs with chronic intranasal disease. METHODS: Cytologic samples of lesions in dogs with chronic intranasal disease were obtained by brushing over a 12-year period. All dogs had complete physical examinations as well as radiographic, rhinoscopic, and cytologic evaluation. Histologic diagnosis, follow-up clinical information, or both were used as the gold standard, and dogs free of disease or with no progression of disease at 1 year were considered negative for neoplasia. Indicators of performance of brush cytology in detecting neoplasia were calculated and included sensitivity, specificity, positive and negative likelihood ratios, and diagnostic odds ratio. RESULTS: Samples of nasal brushings from 138 dogs were evaluated. Of 62 cases of neoplastic disease, true-positive and false-negative diagnoses were made using cytologic evaluation in 44 (71.0%) and 18 (29.0%) cases, respectively. False-negative diagnoses of neoplasia were not attributed to low cellularity, but to the presence of inflammatory cells that masked neoplastic cells. Brush cytology had a sensitivity of 0.71, specificity of 0.99, positive likelihood ratio of 53.94, negative likelihood ratio of 0.29, and diagnostic odds ratio of 188.33. CONCLUSIONS: Brush cytology has good diagnostic accuracy for chronic intranasal lesions in dogs.

Electrophoretic fractionation of creatine kinase isoenzymes and macroenzymes in clinically healthy dogs and cats and preliminary evaluation in central neurologic disease.

BACKGROUND: Information about the electrophoretic distribution of CK-MM, CK-MB, and CK-BB, serum creatine kinase (CK) isoenzymes that are indicators of skeletal muscle, cardiac muscle, and brain lesions, respectively, and CK macroenzymes (macro-CK1 and macro-CK2) in dogs and cats with and without central neurologic disease is scant and equivocal. OBJECTIVES: The objectives of this study were to describe the electrophoretic distribution of CK isoenzymes and macroenzymes in healthy dogs and cats and to provide a preliminary assessment of the utility of CK enzymatic electrophoresis in dogs and cats with central neurologic disease. METHODS: Electrophoretic separation of serum CK isoenzymes and macroenzymes was performed on freeze-thawed serum samples from 20 healthy dogs and 3 dogs with central neurologic disease and from 14 healthy cats and 6 cats with neurologic feline infectious peritonitis (FIP). Electrophoretic separation was also performed on supernatants of homogenized brain, skeletal muscle, and cardiac muscle from both species, to assess the tissue distribution of isoenyzmes in dogs and cats. RESULTS: CK-MM was the predominant isoenzyme in the serum of healthy dogs and cats, followed by macro-CK2 and CK-BB in dogs and by both macroenzymes in cats. In dogs, CK-MB was essentially absent from both serum and homogenized hearts. CK-BB increased in dogs with neurologic disease. In cats, CK-BB was essentially absent from serum, but was present in brain homogenates. Two of 6 cats with FIP had increased macro-CK1 and increased CK-BB activity. CONCLUSIONS: This study identified the electophoretic distribution of CK isoenzymes and macroenzymes of dogs and cats and provided encouraging data about the possible use of CK-BB as a biomarker for canine neurologic disorders, but not for FIP.