Species: Dog Strain/breeder: Beagle / (Harlan, CPB) Sex: Male Age: 9 months Study type: Inhalation Treatment: Low dose group Animal status: Scheduled death Clinical findings: - Organ: Lung Macroscopic finding(s): Irregularly distributed white spots on pleural surface Staining: H&E Literature:

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Abstract

Multiple irregularly distributed white spots were noticed on the surface of the lungs of beagle dogs of the low dose group of a 4 week inhalation study. Similar lesions occurred also in beagle dogs of the mid dose and recovery group of another inhalation study and in one beagle dog of the control group of a 2 week infusion study.

In all cases, clinical chemistry and hematologic laboratory investigations revealed no deviations from the physiological range. Histological examination of the lung showed vacuoles that were positive for lipids in Sudan Red-stained sections in the interstitium adjacent to bronchi and blood vessels as well as beneath the pleural surface. In surrounding alveoli an accumulation of lipid-filled macrophages was found and type-II pneumocytes appeared to be activated.

Interstitial thickening due to an increased inflammatory infiltration was seen in several locations.

The etiology of this incidental that revealed some differences in comparison with alveolar histiocytosis is unknown.