Abstract
This report aims to demonstrate the occurrence of hypertensive pneumothorax secondary to an iatrogenic pneumothorax due to thoracentesis in a feline treated at Hospital Veterinário Roque Quagliato. The presence of primary hypertrophic phenotype cardiomyopathy causes pulmonary hypertension and both generate tri-cavitary effusions, as in the case described. The treatment of effusions, using centesis, can cause complications, such as hypertensive pneumothorax after thoracentesis. It is the role of the Veterinarian to be able to identify and treat such complications.