Pulmonary stenosis in dogs is usually asymptomatic and those that show clinical signs do so after the first year of age. After patent ductus arteriosus, pulmonary stenosis is the second most common congenital cardiovascular malformation in dogs.
Being a congenital pathology, it appears at birth and can be associated with other pathologies such as interventricular defects. Keep reading this article on our site to learn a little more about the anatomy of the heart and pulmonary stenosis in dogs, its symptoms and treatment
Heart and Pulmonary Stenosis
The heart is a hollow organ that is made up of four chambers: the right atrium, left atrium, right ventricle, and left ventricle. In turn, these chambers are connected to each other and to the blood vessels through valves.
We then have the left heart, which is responsible for the oxygenated blood that enters through the left atrium to pass to the ventricle and, through a contraction, enter the general circulation, pumping blood throughout the body.
And on the other hand we have the right heart, which is responsible for collecting blood from the rest of the body to lead it to the lungs where it will be purified.
The right ventricle ejects blood into the pulmonary circulation through the pulmonary artery. This blood flow is controlled by the so-called pulmonary valve.
Pulmonary stenosis consists of a narrowing of the right ventricular outflow tract This narrowing can be located anatomically at the valve level (the most common in dogs), subvalvular or supravalvular, however, the clinical consequences in all three cases are the same.
Pulmonary stenosis affects both sexes, predominating in males and in breeds that have a certain predisposition, such as the beagle, the boxer, the English bulldog, the French bulldog or the schnauzer, among others.
Symptoms of Pulmonary Stenosis in Dogs
Young and resting animals may be asymptomatic and in severe cases syncope (loss of consciousness and body posture).
Due to the narrowing of the valve, there is a higher systolic pressure (contraction) so the right ventricle will first dilate and then its walls will hypertrophy concentrically to compensate.
Cardiac output may fall due to reduced diastolic volume and may cause arrhythmias If there is associated tricuspid dysplasia, it may occur right congestive insufficiency, that is, accumulation of fluid in the abdomen. Prominent jugular pulse may also be seen.
Diagnosis of pulmonary stenosis in dogs
Because it is a pathology that can sometimes be asymptomatic, the veterinarian can detect this disease during one of the routine visits dogThe tests to perform are:
- During cardiac auscultation, a strong ejection murmur can be heard at the left base radiating to the right cranial chest.
- The electrocardiogram may be normal or a pattern of enlargement of the right ventricle may be observed. Ventricular and supraventricular arrhythmias may also be seen.
- A normal cardiac silhouette or right ventricular cardiomegaly may be seen on chest radiographs.
- The definitive diagnosis is made with an echocardiographic study, as well as its classification and severity.
- It must be differentiated from other pathologies such as pulmonary hypoplasia, subaortic stenosis, tetralogy of Fallot, etc.
Treatment and prevention of pulmonary stenosis in dogs
When it is a symptomatic cause ascites will be treated (diuretics), arrhythmias (anti-arrhythmics), blood flow will be improved heart rate (pimobendan), the volume load on the heart and blood pressure (ACEIs) will be reduced, etc.
On the contrary, if it is a dietary cause the use of s alt in the dog's diet will be restricted and you will need a supplementation with omega 3 fatty acids.
It will also be essential to restrict intense physical exercise.
The dog may also need a surgical treatment. There are different techniques such as valvotomy, dilatation with a balloon catheter, pericardial patch, implantation of a ventriculoarterial conduit with or without, etc.
This is a disease with high mortality that requires rigorous monitoring by the veterinarian, therefore we recommend strictly following the professional's instructions. In addition, dogs carrying this disease should not be used as breeding stock, due to their genetic nature.
References
- Cardiovascular conditions in small animals. Belerenian, Guillermo C.
- Congenital malformations in domestic animals. Joaquín Camón Urgel.
