Peer-reviewed veterinary case report
Ultrasound sign that looks like collapsed lung in cats
By Donati, Pablo A et al.·Published in Frontiers in veterinary science·2026·Cá·View original on PubMed →
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Original publication title: False-positive asynchronous-abdominal curtain sign mimicking pneumothorax in cats with severe pulmonary hyperinflation-case report.
- Species:
- cat
Plain-English summary
Two cats were brought to the vet because they were having trouble breathing. An ultrasound showed a sign that can sometimes indicate a collapsed lung, but in these cases, it turned out to be a false alarm caused by severe lung overinflation due to respiratory issues. The vets treated the cats for their breathing problems, which helped them recover completely and improved their breathing mechanics. This case highlights the importance of considering other causes for breathing difficulties in cats to avoid misdiagnosing conditions like pneumothorax.
People also search for: cat breathing problems · cat ultrasound lung issues · feline asthma treatment
Abstract
INTRODUCTION: The asynchronous-abdominal curtain sign (A-ACS) is a suggestive ultrasound artifact for pneumothorax in veterinary medicine. However, its specificity has not been fully established. CASE PRESENTATION: We describe two dyspneic cats displaying a prominent A-ACS despite the absence of findings strongly supportive of pneumothorax. Both cases had severe pulmonary hyperinflation secondary to expiratory flow limitation (feline lower airway disease and suspected anaphylaxis). Sonographic assessment revealed A-ACS and reduced diaphragmatic excursion. Medical management targeting bronchoconstriction and inflammation resulted in complete resolution of respiratory signs, normalization of the abdominal curtain sign (ACS), and improved diaphragmatic excursion in the monitored case. DISCUSSION: These findings suggest that severe pulmonary hyperinflation may represent a cause of false-positive A-ACS, likely resulting from diaphragmatic flattening and altered cardiophrenic mechanics. CONCLUSION: Clinicians should consider pulmonary hyperinflation in cats presenting with A-ACS to avoid misdiagnosis of pneumothorax and unnecessary interventions. Moreover, this sign may offer valuable insights into respiratory dynamics in feline obstructive airway disease.
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Search related cases →Original publication on PubMed: https://pubmed.ncbi.nlm.nih.gov/41675457/