Cytology of 100 samples of abdominal fluid from 100 horses with abdominal disease

Abstract

Summary A total of 100 samples of abdominal fluid (AF) from 100 horses with abdominal disease were evaluated by cytology. Cytology results were subsequently correlated with the final outcome of the disease. The horses were classified into 4 groups: Group I, horses that were treated with conventional (nonsurgical) therapy and recovered; Group II, horses that had surgery and survived; Group III, horses that had surgery but died; and Group IV, horses that were subjected to euthanasia prior to surgery. Statistical analysis showed that both nucleated cell count and total neutrophils were significantly higher in Group III than in Group I; and that the total mesothelial cells were significantly higher in Group III than in Groups I and II. No significant differences were found for erythrocyte counts and fluid total protein levels among the 4 groups. The findings suggest that classifying AF as transudate, modified transudate and exudate, as well as grading of inflammation as mild, moderate and severe on the basis of nucleated cell count (NCC) and fluid total protein (AFTP) can be greatly misleading. Differential identification of the nucleated cells was found to be far more reliable than the NCC alone, with or without the AFTP, and rendered valuable information, which overuled many times a diagnosis of transudate or modified transudate. Bands, metamyelocytes, toxic changes, plasma cells, and neutrophils penetrating rafts or fronds of mesothelial cells, supported a diagnosis of inflammation, even when the NCC, and the AFTP (interpreted according to currently accepted values) suggested otherwise. Several morphological features were found, including some cell types for which little or no mention was found at all in 22 major studies of this fluid in horses. Among these were ‘reddish neutrophils’, large granular lymphocytes (LGL), plasma cells, Mott cells, blasts, and a unique hitherto undescribed granular mesothelial cell.

Peritoneal fluid changes in horses subjected to small colon distension

“…Moreover, the occurrence of total protein concentrations under the standard reference value of 2.5g/dL even with intestinal ischemia reported here support previous studies that suggested a maximum reference value of 1.5g/dL (Browlow et al 1981, Garma-Aviña 1998. Some authors consider that 2.5g/dL should be used, considering the difficulty in obtaining accurate values lower than this with the refractometer, which is the most widely used method (DeHeer et al 2002).…”

Cytology of the Normal and Abnormal Choroid Plexi in Selected Domestic Mammals, Wildlife Species, and Man

“…Red granules are also known to appear occasionally in the cytoplasm of mesothelial cells of the abdominal fluid, and cases in horses have been documented. 6 More studies are necessary to accurately establish the relative frequency of the various cell types found in animals and humans. Also, a topographical cytological study on the choroid plexi would be useful to pinpoint the precise spatial location of these cells within the choroid plexi, as well as to determine whether all the ventricles share the same cytological composition.…”

Overview of Clinical Pathology and the Horse

“…Evaluation of the sediment smear along with the protein levels and PCV can characterize the disease process. [38][39][40][41][42][43][44][45][46] The PP (total solids) should be used to determine the pathogenesis of the fluid development. Fluids with low protein levels (less than 1.5 g/dL) are considered pure transudates; this implies that water has leaked from vessels as a result of altered fluid forces, including hydrostatic and oncotic pressures.…”