Читать книгу Canine and Feline Respiratory Medicine - Lynelle Johnson R., Lynelle R. Johnson - Страница 53

Positive bacterial and mycoplasmal cultures must be interpreted in conjunction with cytology. The presence of squamous cells or Simonsiella bacteria is suggestive of upper airway contamination. In these cases, it is not uncommon to observe growth of two to four types of aerobic bacteria (usually oral flora) with or without Mycoplasma. Because approximately one‐third of healthy dogs and almost three‐fourths of healthy cats can have positive tracheal cultures (Table 2.5), strict attention should be paid to upper airway contamination of BAL samples and appropriate interpretation of BAL cultures. Quantitative bacterial cultures provide evidence for bacterial infection when >1.7 × 10³ bacterial colony forming units per milliliter of fluid grow on culture. In addition, detection of more than two intracellular bacteria in any of 50 examined high‐power fields is a reliable indicator of lower respiratory tract infection (Peeters et al. 2000), although approximately one‐quarter of cases lack intracellular bacteria (Johnson et al. 2013). Lower respiratory tract infections are often characterized by culture of several species of bacteria, including anaerobes (Johnson et al. 2013).

Table 2.5 Lower respiratory tract flora found in healthy dogs and cats.

Dogs (McKiernan et al. 1982)	Cats (Dye et al. 1996)
Bordetella Corynebacterium Escherichia coli Enterobacter Klebsiella Pasteurella Pseudomonas Staphylococcus Streptococcus Mycoplasma	Acinetobacter Bordetella Corynebacterium Enterobacter Flavobacterium Klebsiella Pasteurella Staphylococcus α‐Streptococcus

Table 2.6 Characteristics of pleural fluid.

	Protein (g/dl)	Cell count (per μl)	Etiology
Transudate	≪1.5	≪1000	Hypoalbuminemia
Modified transudate	<2.5	500–2500	Right heart failure Pericardial disease Neoplasia Hernia
Exudate	>3.0	>5000	Feline infectious peritonitis Neoplasia Hernia Lung lobe torsion Pyothorax
Chylous	>2.5	>500	Idiopathic Cardiomyopathy Heartworm disease Neoplasia Lung lobe torsion
Hemorrhagic	>3.0	>1000	Trauma Coagulopathy Neoplasia Lung lobe torsion