Infectious Disease Management in Animal Shelters. Группа авторов

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spp., Trichuris spp.). If a passive flotation method is pursued, sodium nitrate (e.g. Fecasol®, Vetoquinol, Fort Worth, TX) or saturated salt solutions should be used. Though they are ideal for centrifugation techniques, the high viscosity of sugar solutions and the lower specific gravity of zinc sulfate solutions can impede the passive flotation process (Zajac and Conboy 2012). In the absence of centrifugation or proper flotation solutions, the likelihood of inaccurate test results warrants consideration of additional diagnostic testing or empirical treatment of patients exhibiting clinical signs consistent with parasitic infection.

      Once the sample is prepared and the surface layer transferred to a coverslip, the sample should be scanned under the 10× objective lens of a microscope. To maximize the contrast between parasites and background debris, the microscope condenser should be lowered and the light intensity and diaphragm should be reduced. Samples prepared in sodium nitrate solution should be evaluated immediately to avoid distortion of any parasites and crystallization of the preparation (Bowman 2014; Zajac and Conboy 2012).

      4.3.2.4 Urinalysis

      Urinalysis is useful for the evaluation of renal function, assessment of urinary tract diseases, and the analysis of systemic disease processes that impact the urinary system. There are four main diagnostic tests utilized to evaluate the urinary system: urine specific gravity, urine chemical analysis (i.e. use of reagent strips or “dipstick”), urine sediment analysis, and urine culture (Table 4.3). Urine sediment analysis and urine culture are of the most utility regarding the diagnosis of infectious diseases, though direct testing may be warranted under certain circumstances (e.g. canine distemper virus, leptospirosis).

      Analysis of urine sediment can aid in the diagnosis of bacterial, fungal, algal, and parasitic diseases of the urinary tract. The sample should be obtained through cystocentesis or catheterization in order to confirm that any pathogens identified originate in the kidneys or bladder. If that is not feasible, a midstream voided urine sample can be utilized to minimize contamination from the urethra and external environment. After obtaining the specific gravity and urine chemical analysis, the sediment can be prepared for microscopic evaluation through low‐speed centrifugation (1,500–2,000 RPM for 5 minutes), decanting of the supernatant, resuspension, and preparation on a glass slide. Both unstained and stained drops of urine should be evaluated for cells, casts, crystals, and infectious organisms. Fat droplets, spermatozoa, mucous, and other contaminants may also be identified. Preparations can be stained with a Romanowsky stain after drying for detailed identification of cellular elements and examination under oil immersion; however, crystals will be dissolved by the fixative component. Supravital stain (e.g. Sedi‐Stain) or new methylene blue can be applied to a wet‐mounted sample if preservation of crystals is desired; however, cellular detail is lost, examination under oil immersion is not possible, and accumulation of bacteria and stain precipitate resulting in sediment artifacts are common (Anthony 2014). The presence of more than five white blood cells per high‐power field indicates urogenital tract inflammation and the sample should be carefully evaluated for the presence of bacteria (Tripathi et al. 2011). Bacteria in the absence of white blood cells could indicate contamination of the sample during collection or processing. Both rod and coccoid bacteria can be found, with progressively motile rods being the most common. Yeast are the most common fungal organisms identified and are usually contaminates from the lower urinary tract (Rosenfeld and Dial 2010c).

      4.3.3 Secondary Diagnostic Testing

      4.3.3.1 Complete Blood Count and Blood Chemistry Analysis

      Blood chemistry analysis may include a variety of parameters to assess the function of major organ systems (e.g. renal, hepatic), total proteins, electrolytes, and metabolism of carbohydrates and lipids. These assessments are most thoroughly and accurately performed through the use of calibrated, automated biochemical analyzers either in‐house or at a diagnostic laboratory. If complete biochemical profiling is not available, crude assessments of total proteins, blood urea nitrogen (BUN), and blood glucose can be conducted in almost any setting.

      As mentioned above, after obtaining a PCV, an analysis of the remaining plasma can easily be undertaken. Plasma color and transparency should first be visually assessed. For both dogs and cats, plasma is normally clear and colorless; yellow plasma indicates icterus, pink or red indicates hemoglobinemia, and white


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