Chylous effusions revisited

Varying terms and criteria have been used in the veterinary literature to characterize milky opaque pleural effusions through the years. This article addresses ideas widely repeated in the veterinary and human literature upon which time, experience, diagnostic techniques, experimental data, and improved understanding of pathogenesis have cast doubt. Topics discussed include terminology, pathogenesis of chylous and pseudochylous effusions, criteria for differentiation of chylous from pseudochylous effusions, and clinicopathologic changes associated with drainage of chylous effusions.     

Chylothorax associated with cryptococcal mediastinal granuloma in a cat

A 10-year-old neutered female cat had chylothorax, precaval syndrome, and a mediastinal granuloma resulting from infection with Cryptococcus neoformans. Diagnosis of a chylous effusion was made by cytologic examination of pleural fluid and by finding higher triglyceride levels in the effusion than in serum (825 vs. 64 mg/dl, respectively). Postmortem examination revealed cryptococcal organisms in the mediastinal granuloma, lungs, cerebral meninges, and connective tissues adjacent to the thyroid gland. Chylous effusion in a cat associated with cryptococcosis has not been reported previously. Cryptococcosis should be included in the differential diagnosis in chylous effusions in cats.     

Experimental model of hypochloremic metabolic alkalosis caused by diversion of abomasal outflow in sheep

Hypochloremic metabolic alkalosis accompanied by hypokalemia and hyponatremia was induced experimentally in 7 adult sheep by diversion (loss) of gastric contents through an Ivan and Johnston cannula placed in the cranial part of the duodenum just distal to the pylorus. Cannula placement was easily accomplished, and cannulae were tolerated well by the sheep. Volume of effluent produced during the 60- to 120-hour period of diversion ranged from 7.7 to 14.9 L and tended to be greatest during the first 24 hours. All sheep became dehydrated, with mean PCV and plasma total protein concentration increases of 94.2 and 61.7%, respectively. Plasma chloride concentration decreased in linear fashion from a prediversion mean of 113 mEq/L (range, 111 to 117 mEq/L) to an end-point mean of 54 mEq/L (range, 45 to 65 mEq/L). Plasma sodium and potassium concentrations also decreased, though potassium concentration increased terminally. There were rapid increases in arterial blood pH and bicarbonate and base excess concentrations during the first 48 hours after diversion. However, during the final stages of diversion, sheep developed superimposed metabolic acidosis with increased plasma lactate concentration and high anion gap.     

Diagnosis and successful treatment of Cryptococcus neoformans variety grubii in a domestic ferret

A domestic ferret was presented for episodic regurgitation. Cytologic examination and culture of an enlarged submandibular lymph node revealed Cryptococcus neoformans variety grubii (serotype A). The ferret was successfully treated with itraconazole. This is the first documented case of Cryptococcus neoformans variety grubii in a ferret in the United States.     

Effects of hemolysis on plasma electrolyte and chemistry values in the common green iguana (Iguana iguana).

Hemolysis of serum and plasma samples is a common problem in veterinary diagnostic laboratories. We measured the effects of hemolysis on nine plasma analytes in 10 clinically normal common green iguanas (Iguana iguana). Blood samples with moderate and marked hemolysis were produced from each iguana by freezing, centrifuging, and decanting plasma from a portion of each blood sample, and combining the nonhemolyzed plasma with different amounts of hemolyzed plasma from the same individual. Moderate hemolysis significantly increased plasma phosphorus levels. Marked hemolysis significantly increased plasma values of potassium, phosphorus, total protein, and aspartate aminotransferase. The severity of hemolysis must be considered when interpreting values for these analytes in iguana plasma.     

Sequential morphological and quantitative changes in blood and bone marrow neutrophils in dogs with acute inflammation.

Blood and bone marrow morphology were studied sequentially in dogs during experimental inflammation induced by intramuscular injection of turpentine. Depletion of the bone marrow storage pool of mature neutrophils and an increase in mitotic activity and number of early granulocyte precursors were evident within 24 hours. During the next three days, intense granulocytic hyperplasia resulted in replenishment of the bone marrow storage pool. Neutrophils with foamy vacuolation and increased basophilia of the cytoplasm (toxic neutrophils) were present in the blood by eight hours postinjection. The number of toxic neutrophils paralleled the intensity of clinical signs and changes in rectal temperature but not the number of band neutrophils. This indicates that changes in number of toxic neutrophils in sequential leukograms can be a prognostic indicator in dogs with severe inflammation.     

Comparison of three preoperative skin preparation techniques in ponies

The purpose of this study was to evaluate the efficacy of 3 preoperative skin preparations (povidone‐iodine [PI] removed with 70% isopropanol, and 4% chlorhexidine gluconate [CG] removed with either 70% isopropanol [CA] or sterile saline solution [CS]) in ponies. Eighteen ponies were randomly assigned to one of the 3 preoperative skin preparation groups. The skin of ponies was aseptically prepared with PI removed with alcohol, or 4% CG removed with either alcohol or sterile saline solution. The antimicrobial efficacy of each skin preparation technique was assessed quantitatively by culturing for surface bacteria with replicating organism detection and counting plates. The percentage of negative cultures, the percentage of cultures with >5 colony forming units (CFU) and the percentage bacterial reduction after the cleansing scrub, the sterile scrub, and the surgical procedures were compared. There was a significant difference between CG and PI in percentage bacterial reduction after the cleansing scrub, but no significant difference at any other time (sterile scrub, post operative skin sampling). In a comparison of the number of negative microbial cultures at each sampling point, there were no significant differences among the 3 skin preparation techniques. There were no significant differences among the treatment groups comparing the number of cultures with a high colony count (>5 CFU) after the cleansing scrub. Skin preparation with CS and PI resulted in significantly fewer cultures with >5 CFU after the sterile scrub than CA. Post operatively, CA had a higher number of samples with >5 CFU than CS and PI. PI removed with alcohol and 4% CS are equally effective in the reduction of skin bacteria after a sterile skin scrub in the operating room; however, CG was more effective in reducing bacterial numbers after the cleansing scrub. The number of cultures with high bacterial counts was greater post operatively, when alcohol was used as a rinse with chlorhexidine. In cases where a sterile scrub is not performed following a cleansing scrub, CG may be a better choice than PI. CA should not be used as a presurgical skin preparation method in ponies.     

Pharmacokinetics of phenolsulfonphthalein in horse and pony mares

Pharmacokinetics of phenolsulfonphthalein (PSP) in horse and pony mares was determined after injection of 1 mg/kg of body weight, IV. A plasma PSP concentration vs time curve was described adequately in horses and ponies by an open, 2-compartment model. There were significant differences in the elimination phase parameters, apparent volume of distribution at steady state, and apparent volume of distribution of horses and ponies. The harmonic mean elimination half-life of PSP in horses was significantly longer (P less than 0.001) than that in the ponies (16.4 and 10.0 minutes, respectively). The mean plasma clearance of PSP in horses was significantly (P less than 0.05) less than that in ponies (0.00554 and 0.00701 L/min/kg, respectively). There was no difference between horses and ponies in the metabolic clearance of PSP. The fraction of the administered dose of PSP excreted in the urine in the first 15 minutes was not significantly different between horses and ponies.