Feline secondary spontaneous pneumothorax: A retrospective study of 16 cases (2000–2012)

Objective To describe the demographics, clinical characteristics, diagnostic findings, underlying etiologies, treatment, and outcome associated with secondary spontaneous pneumothorax (SSP) in cats; and to identify clinical feature differences among cats with asthma associated secondary spontaneous pneumothorax (AASSP) versus nonasthma‐associated secondary spontaneous pneumothorax (NAASSP). Design Retrospective case series. Setting University teaching hospital. Animals Sixteen client‐owned cats with secondary spontaneous pneumothorax. Interventions None. Measurements and Main Results Domestic short hair was the predominant breed in this study ( n = 15). The median age was 8 years old (range: 7 weeks to 17 years) with no sex predilection. Fourteen cats were affected by multi‐lobar pulmonary pathology of infectious, inflammatory, or neoplastic causes. Asthma was the most common cause of spontaneous pneumothorax (25%). Ten of 12 treated cats survived the initial episode of spontaneous pneumothorax to discharge with medical management, including all 4 cats with AASSP. Reoccurrence was documented in 4 cats. Pulmonary lobectomy was curative for 1 cat with congenital accessory lung lobe emphysema. No difference in clinical presentation was identified between cats with AASSP and cats with NAASSP. Conclusions Feline SSP is frequently associated with extensive pulmonary pathology. Supportive medical management is most appropriate, except in rare cases with focal congenital abnormalities that may benefit from surgical intervention. AASSP appears to carry a good prognosis for short‐term outcome (survival to discharge). Clinical assessment, imaging, and invasive diagnostics were required to differentiate between AASSP and NAASSP.