Introduction

This retrospective descriptive study aimed to compare computed tomography (CT) and surgical findings in feline pyothorax.

Methods

Clinical records were searched for cats diagnosed with pyothorax based on cytology and/or culture that had CT performed between March 2006 and January 2021. Available CT and non-standardised surgical reports were compared.

Results

Thirty-six cats were included. The majority of cats were male (29/36), outdoor (24/36) domestic short hair cats (17/36) from multicat households (22/36). Pasteurella multocida was the most commonly cultured microorganism (9/36). Seventeen cats were managed surgically and 19/36 medically. Overall survival was 67%. All cats had thoracostomy tubes placed prior to surgery. Reasons for proceeding to surgery were: failed medical management (7/17), a lesion identified on CT that was considered surgical (7/17), unsuccessful drainage via thoracostomy tube (2/17), continuous pneumothorax secondary to thoracostomy tube placement (1/17). Median number of days between CT and surgery was 1 day (range 0–6 days). CT identified pneumothorax in 24/36 cats. All of these cats had thoracocentesis or thoracostomy tubes placed prior to CT. Abnormal pleura was noted in 18/36 cats on CT; 2/7 cats had this confirmed at surgery. CT showed mediastinal changes in 10/36 cats; 3/5 cats had this confirmed at surgery. Thirty cats had atelectasis on CT; 3/15 cats had this confirmed at surgery. Parenchymal changes other than atelectasis were identified on CT in 23/36 cats; 5/11 cats had this confirmed at surgery. Enlarged lymph nodes were described in 24/36 cats on CT; 1/12 of these cats had this confirmed at surgery. Five cats had discrete parenchymal lesions on CT; 2/4 of these cats had similar lesions described at surgery. Abnormalities identified at surgery but not on CT included mediastinal changes (9/17), lung puncture wounds (2/17), a lung consolidation (2/17), abnormal pleura (2/17), an abscess between the left caudal lung lobe and body wall (1/17), a discrete parenchymal lesion (1/17), atelectasis (1/17).

Conclusions

CT and surgical findings varied which could be due to a progression of the disease that could had occurred between CT and surgery, interventions carried out between CT and surgery or missing information in surgical reports.

Disclosures

No disclosures to report.