Ventricular septal defect (VSD) is a heart defect that results in blood being diverted from one side of the heart to the other. This can lead to a range of symptoms in dogs, including difficulty breathing, fainting, coughing, and pale gums.
While the exact cause is unknown, diagnosis and treatment can help manage the defect and its symptoms. This article will provide an overview of VSD in dogs, explaining the symptoms, causes, diagnosis, treatment, and prognosis.
Symptoms and Types
Dogs with VSD may exhibit difficulty breathing, exercise intolerance, fainting, coughing, and pale gums. These symptoms are caused by an irregular communication in the ventricular septum that creates a shunt, or diversion, of blood from one side of the heart to the other.
The amount and direction of the blood diversion depends on the size of the defect, the resistances of the blood vessels, and any other anomalies present. Most VSDs in small animals are subaortic and located beneath the septal leaflet of the tricuspid valve. They may be small, moderate-sized, or large.
Diagnosis is typically made through a physical exam, blood tests, X-rays, and an echocardiogram. Treatment depends on the size of the defect, but may include surgical repair, pulmonary artery banding, activity restrictions, and a low-sodium diet.
Dogs with VSD may have a normal lifespan if no concurrent diseases pose a direct threat.
Causes
The underlying cause of VSD in dogs is unknown. However, a genetic basis is suspected. Studies suggest that VSDs may be caused by an abnormality of the muscles in the heart’s wall or an abnormality of the proteins that make up the wall. Other possible causes include chromosomal anomalies, certain viral infections, and toxins. It’s also possible that VSDs can be inherited from parents. In some cases, the cause of VSD is never identified.
Regardless of the cause, VSDs can cause an irregular communication between the left and right ventricles, resulting in a shunt of blood from one side of the heart to the other.
Diagnosis
A veterinarian will conduct a thorough physical examination and history, as well as complete blood profiles, chemical blood profiles, complete blood counts, urinalyses, and electrolyte panels to rule out other diseases.
To detect larger VSDs and visualize heart enlargement, high blood pressure in the lungs, chronic heart failure, and right to left shunts, thoracic X-rays are also taken.
In addition, a two-dimensional echocardiographic study is used to view heart activity and detect heart enlargement and other abnormalities.
The size of the defect and vessel resistances determine the direction and volume of the shunt. If moderate-sized or large VSDs are present, an enlarged right heart may be detected.
All of these tests are used to diagnose VSDs in dogs.
Treatment and Management
Treatment and management of VSD in pets typically involve:
- Activity restriction for those displaying signs of congestive heart failure (CHF)
- A low sodium diet to reduce pressure on the heart if CHF is present
- Regular follow-up appointments for monitoring progress, retaking X-ray and ultrasound images, and adjusting medications or therapies as needed
For large shunts, surgical repair during a cardiopulmonary bypass may be necessary, while moderate or large shunts may undergo pulmonary artery banding as a palliative procedure.
Dogs with overt CHF are usually given 6 to 18 months to live with medical treatment, while those with small shunts may have a normal lifespan if no other diseases are present.
Owners should follow their veterinarian’s advice on physical routine and management strategies for their pet with VSD.
Overview of VSD in Dogs
VSD in pets causes an abnormality in the ventricular septum, diverting blood from one side of the heart to the other. This irregular communication and shunt is determined by the size of the defect, the resistance of the blood vessels, and the presence of other anomalies.
Most VSDs in small animals are subaortic and found beneath the tricuspid valve. Symptoms can include difficulty breathing, exercise intolerance, fainting, coughing, and pale gums. The underlying cause is unknown, but a genetic basis is suspected.
Diagnosis is done through a physical exam, blood profile, X-rays, and echocardiographic study. Treatment and management vary depending on the size of the shunt and may include surgery, banding, activity restrictions, and a low sodium diet.
Follow-up appointments are necessary to monitor progress and adjust medications or therapies. Dogs with small shunts may have a normal lifespan with proper care.
Assessing the Severity of the Defect
The severity of the defect can be assessed by evaluating the size of the defect, resistances of the blood vessels, and presence of other anomalies.
The size of the VSD determines the direction and volume of the shunt.
Blood vessel resistances must also be taken into account, as they affect the amount of blood that is diverted from one side of the heart to the other.
Additionally, the presence of other anomalies must be taken into consideration in order to determine the severity of the defect.
The combination of these factors helps to determine the most effective treatment for the VSD.
Impact on the Dog’s Quality of Life
The severity of a VSD directly affects a dog’s quality of life, depending on the amount of blood being diverted and the presence of other anomalies. If a dog has a small VSD, they may have a normal lifespan with no concurrent diseases posing a direct threat to their health.
Moderate or large VSDs may require surgical repair, pulmonary artery banding, or activity restriction. Dogs showing signs of congestive heart failure (CHF) may be given 6 to 18 months to live with medical treatment. Low sodium diets may be recommended to minimize pressure on the heart if CHF is diagnosed.
Regular follow-ups are necessary for monitoring progress, retaking X-ray and ultrasound images, and adjusting medications or therapies as needed. Breeders should restrict breeding of dogs diagnosed with VSD, as it is thought to be genetically transmitted.
Prognosis and Follow-up Care
Prognosis and follow-up care for dogs with VSD depend on the size of the defect, blood vessel resistances, and presence of other anomalies. Most patients can be treated on an outpatient basis, while larger shunts may require surgical repair. Moderate or large shunts may undergo pulmonary artery banding as a palliative procedure.
Dogs with overt CHF are given 6 to 18 months to live with medical treatment. Dogs with small shunts may have a normal lifespan if no concurrent diseases pose a direct threat. Activity restriction, low sodium diet, and regular follow-up appointments are recommended for all dogs with VSD.
Restricting breeding of dogs diagnosed with VSD is advised as it is thought to be genetically transmitted.
