Goals of Treating Aortic Senosis
The goals and types of treatment for dogs diagnosed with subaortic stenosis (SAS) are somewhat controversial, even among veterinarians. There is no universally agreed-upon treatment protocol. Certainly in severe cases, the therapeutic goal is to try and reduce the risk of fainting episodes (syncope) and sudden death.
If the dog has developed congestive heart failure as a result of SAS, treatment for that condition should be implemented; this typically involves administration of a combination of several different medications. If the dog has SAS but has not yet developed many or any recognizable symptoms of the condition, recommendations for treatment can vary. Activity restriction is usually suggested in most cases, as exertion can bring on bouts of fainting and can exacerbate the risk of sudden death. Low sodium diets can be beneficial for dogs with heart failure and with SAS. Affected animals should not be bred, and their siblings should be assessed and monitored closely for any signs of heart disorders.
The only truly definitive treatment for aortic stenosis is open-heart bypass surgery to remove the obstructive lesion. However, this is rarely performed in veterinary clinics – even in those with specialized veterinary cardiologists on their staff. Some experts have used balloons to dilate the aorta during cardiac catheterization. Unfortunately, the results of these invasive surgical procedures have not shown any prolonged survival times over conservative medical (drug) management.
Medical management of dogs with SAS is designed to relieve discomfort. It is not designed to “cure” the condition. Certain medications in a class of drugs called “beta blockers,” together with other medications, have been used and advocated by some veterinarians to manage SAS, although little research has been done to establish the efficacy of drug therapy for dogs with SAS. Owners should consult with their veterinarian, and probably seek referral to a veterinary cardiology specialist, to decide upon the best course of treatment for their dog.
The outlook for dogs with subaortic stenosis is quite variable. Dogs with very mild disease may live a full and normal life, never showing any noticeable signs of their heart condition. On the other hand, dogs with moderate to severe SAS often die without warning within the first several years of life. Alternatively, they may develop congestive heart failure and will be euthenized or die from that condition.