History and presenting signs
Dilatation of the pulmonary artery (thin arrow at 2 o'clock position) and ventricular enlargement in a dog with pulmonic stenosis. This photograph is reproduced from "Canine & Feline Cardiology" by Phillip R Fox with the permission of Elsevier.
Enlargement of the right atrium may be seen on the dorso-ventral view in animals with tricuspid valve regurgitation.
The special imaging technique by which contrast media is passed through the heart chamber and the sequential X-rays are taken (angiography) is very helpful to confirm the diagnosis.
Angiography showing dilatation of the pulmonary artery (P), thickening of the wall of the right ventricle due to hypertrophy (W) and thickening and dysplasia of the pulmonic valve (arrow) in a dog with valvular pulmonic stenosis. This photograph is reproduced from "Canine & Feline Cardiology" by Phillip R Fox, with the permission of Elsevier .
DogsChihuahuas, English Bulldogs and Fox Terriers as having a higher prevalence for the disease than the general population (Patterson Dog. Circ.Res 23:171, 1968). Another report (Canine & Feline Cardiology by Phillip R Fox 1988) also cites Beagles, Samoyeds and Cocker Spaniels as having increased risk. In a recent UK publication (Diseases of the Cardiorespiratory System by Mike Martin and Brendon Corcoran, 1997) the Miniature Schnauzer and Boxer are also listed as being commonly affected, but Samoyeds, Chihuahuas, Fox Terriers and English Bulldogs are not mentioned. Pulmonic stenosis has been shown to be hereditary in Beagles and is thought to be polygenic (not a single gene expression, but multiple genes are involved). In Breed Predispositions to Disease in Dogs and Cats by Gough and Thomas the Mastiff is mentioned.
Severely affected cases can be treated using a relatively new technique called balloon valvuloplasty in which a catheter with a small balloon on the end is guided to the position of the narrowing, and the balloon is then inflated to open the constriction. This procedure appears to be good in the short-term, but long-term studies are needed.
Updated October 2013