Congenital heart disease in cats

In the feline species the most common congenital defects are atrioventricular dysplasia (with the mitral valve more commonly affected than the tricuspid valve) and ventricular septal defects. Pulmonic and aortic stenosis are relatively rare. Patent ductus arteriosus is extremely uncommon. However one has to be aware that cats often have multiple congenital defects and do present as adults with congenital heart disease. They do amazingly well with complex cardiac malformations. Tetralogy of Fallot is the most frequently recognised, but others like AV-canal defects, and cor triatriatum sinister are, with the common availability of echocardiography, more frequently diagnosed. This paper is the third in a series on congenital heart disease in small animals.