ABSCESSING PNEUMONIA IN A PET RAT – A DIAGNOSTIC APPROACH
DOI:
https://doi.org/10.26873/SVR-2311-2026Keywords:
abscess, lung ultrasound, pneumonia, rat, respiratory disease, MycoplasmaAbstract
A two-year-old 235 g female pet rat (Rattus norvegicus) was presented with weight loss and dyspnoea. Clinical findings included cachexia, chromodacryorrhoea, cyanotic mucous membranes, severe dyspnoea and bronchovesicular wheezes. Thoracic radiographs showed a mixed interstitial-alveolar pattern with cardiac displacement. Rat thoracic ultrasound revealed multiple nodular lesions, abnormal curtain signs. Based on the diagnostic imaging the diagnosis was established as abscessing pneumonia. The animal tested seropositive for Mycoplasma pulmonis, Filobacterium rodentium, rat theilovirus, and Pneumocystis carinii, whereas it was seronegative for rat coronavirus (RCV) and Sendai virus. Bacteriological examination of the bronchoalveolar lavage showed the presence of Bordetella bronchiseptica, Staphylococcus aureus and Acinetobacter baumanni, whereas lung tissue culture showed the presence of Acinetobacter pittii, and Staphylococcus aureus. Due to poor prognosis, euthanasia was elected. Necropsy, histopathology and bacteriology confirmed chronic interstitial lung abscessation and pyogranulomatous bronchopneumonia. In the presented case, the final diagnosis was chronic interstitial pneumonia and pyogranulomatous bronchopneumonia caused by M. pulmonis, P. carinii, S. aureus, and A. pittii. The recommended optimal diagnostic work-up for respiratory disease includes clinical examination, lung ultrasound, thoracic radiography, haematological analysis and bronchoalveolar lavage. In this case, lung ultrasound, particularly due to the small body size of the animal, proved to be a quick diagnostic method and compared with radiography, a tool with better diagnostic and prognostic outcomes. Therefore, lung ultrasonography should be part of the diagnostic work-up for thoracic pathologies, especially when high-resolution computed tomography imaging is not possible. Pathogen identification should include bacteriology as well as PCR testing. Precise pathogen analysis, together with antibiotic sensitivity testing, helps the practitioner choose the optimal antibiotic and supportive care, following guidelines for the prevention of antimicrobial resistance.
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Copyright (c) 2026 Anna Piskovska, Karel Hauptman, Miša Škorič, Vladimir Jekl*
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