CTfindings, management and short‐term outcome of dogs with pyothorax: 101 cases (2010 – 2019)

Abstract

To describe diagnosis, CT findings, management and short-term outcome of a large population of canine pyothorax cases.MethOds: Retrospective analysis of 101 canine pyothorax cases at two UK referral centres. Medical records and CT images were reviewed. Dogs were included if pre-and post-contrast CT was performed within 48 hours of presentation.Results: CT abnormalities included pleural thickening (84.1%), pannus (67.3%), pneumothorax (61.4%), mediastinal effusion (28.7%), pulmonary (13.8%) and mediastinal (7.9%) abscessation, foreign body presence (7.9%), foreign body tracts (6.9%) and pneumonia (6.9%). Seventy-one percent of dogs were managed surgically, of which 90.2% survived, and 29% were managed medically, of which 72.4% survived. Overall mortality was 14.8% and 86.6% of these dogs died within 48 hours of admission. All dogs with evidence of a foreign body on CT underwent surgery. clinical significance: Mortality in our population was low and most dogs that died did so within 48 hours of hospitalisation, regardless of management type.

Etiology and effusion characteristics in 29 cats and 60 dogs with pyothorax (2010‐2020)

“…In another study of pyothorax, 75% of cats came from multi‐cat households, but those cats did not have a history of fighting or bite wounds and the authors could only determine an etiology for pyothorax in 3/55 cases 11 . Most cats with pyothorax in our study had access to the outdoors (59%), similar to findings in large studies of pyothorax from Europe 3,11 . Several studies have failed to discover an underlying cause for pyothorax in cats, 1,11 whereas only 2/29 cats did not have a cause of pyothorax identified in our study.…”

“…Some studies have reported monomicrobial infection in the majority of both cat 4 and dog 3 cases of pyothorax; however, the majority of cases here and in other studies 2 , 10 , 18 had polymicrobial infection, which emphasizes the need to perform both aerobic and anaerobic cultures. Antimicrobial susceptibility testing is essential to ensure efficacy of treatment against all infecting organisms.…”

“… 11 Most cats with pyothorax in our study had access to the outdoors (59%), similar to findings in large studies of pyothorax from Europe. 3 , 11 Several studies have failed to discover an underlying cause for pyothorax in cats, 1 , 11 whereas only 2/29 cats did not have a cause of pyothorax identified in our study.…”

“…Pyothorax in cats and dogs is characterized by intrapleural accumulation of proteinaceous fluid with high white blood cell count, large percentage of inflammatory cells, and variable types of bacteria. Most infections in dogs and cats are polymicrobial, 1,2 but some studies have found single organism infection 3,4 . Diagnosis of bacterial pyothorax is often readily achieved because of the presence of intracellular bacteria on cytology in 68% of dogs and 91% of cats 2 .…”

“…Most infections in dogs and cats are polymicrobial, 1 , 2 but some studies have found single organism infection. 3 , 4 Diagnosis of bacterial pyothorax is often readily achieved because of the presence of intracellular bacteria on cytology in 68% of dogs and 91% of cats. 2 However, empirical use of antimicrobial agents before sample collection could impact the diagnostic utility of both cytology and culture.…”