Severe bronchiectasis resulting from chronic bacterial bronchitis and bronchopneumonia in a jungle cat

Abstract

Bronchiectasis is irreversible bronchial dilation that can be congenital or acquired secondary to chronic airway obstruction. Feline bronchiectasis is rare and, to our knowledge, has not been reported previously in a non-domestic felid. An ~10-y-old female jungle cat (Felis chaus) was presented for evaluation of an abdominal mass and suspected pulmonary metastasis. The animal died during exploratory laparotomy and was submitted for postmortem examination. Gross examination revealed consolidation of the left caudal lung lobe and hila of the cranial lung lobes. Elsewhere in the lungs were several pale-yellow pleural foci of endogenous lipid pneumonia. On cut section, there was severe distension of bronchi with abundant white mucoid fluid. The remaining lung lobes were multifocally expanded by marginal emphysema. Histologically, ectatic bronchi, bronchioles, and fewer alveoli contained degenerate neutrophils, fibrin, and mucin (suppurative bronchopneumonia) with rare gram-negative bacteria. Aerobic culture yielded low growth of Proteus mirabilis and Escherichia coli. There was chronic bronchitis, marked by moderate bronchial gland hyperplasia, lymphoplasmacytic inflammation, and lymphoid hyperplasia. The palpated abdominal mass was a uterine endometrial polyp, which was considered an incidental, but novel, finding. Chronic bronchitis and bronchopneumonia should be considered as a cause of bronchiectasis and a differential diagnosis for respiratory disease in non-domestic felids.

Keywords: Escherichia coli; Felidae; Proteus; exotic animal; lung; respiratory disease; zoo animal.

Figure 1.

Severe bronchial pattern with bronchiectasis in the caudal lung lobes in thoracic radiographs of a jungle cat. A. Bronchiectasis (circled) within the caudal lung lobes. * Denoted area corresponds to similarly annotated left caudal lung lobe shown in Fig. 2A. B. On dorsoventral view, bronchial walls are markedly thickened (“donuts”, arrowheads).

Figure 2.

Gross and histologic features of bronchiectasis, chronic bronchitis, and bronchopneumonia in a jungle cat. A. The left caudal lobe (*) and hilar regions of the cranial lobes are consolidated, dark-red, and heavy with several flat, pale-yellow, pleural foci of endogenous lipid pneumonia (arrowheads). The remaining lung lobes are emphysematous (x). Bar = 1 cm. B. On cut section of the formalin-fixed caudal lung lobe, dilated bronchi and bronchioles contained abundant white viscous mucoid material (#) and had markedly thickened walls. Bar = 1 cm. C. Histologically, bronchial dilation and wall thickening, with filling of the lumina with abundant exudate (#). H&E. D. The wall of a bronchus is thickened by hyperplastic submucosal glands, hyperplastic bronchial-associated lymphoid tissue, and mixed inflammatory cells predominated by lymphocytes and plasma cells (inset, lower right). Degenerate neutrophils and debris fill the lumen (inset, upper left). Smooth muscle bundles in the lamina propria are markedly reduced in frequency and size (arrowhead). H&E. E. Suppurative inflammation within a thickened inflamed terminal bronchiole (arrowhead) extends into surrounding alveoli (*) along with fibrin and edema (x). H&E. F. Uncommonly, gram-negative bacteria are present within suppurative luminal exudate. Gram stain.

Figure 3.

Gross and histologic features of a uterine endometrial polyp in a jungle cat. A. The right uterine horn is focally expanded by a firm, tan, pedunculated, intraluminal mass that is homogeneous on cut surface (inset). Bar = 1 cm. B. Histologically, the mass is comprised of a pedunculated exophytic mass of proliferating endometrial mucosa, stroma, and smooth muscle with multifocal squamous metaplasia (inset).