Structural Heart Problems in the Bichon Frise

It helps to separate two entirely different failure modes. A worn-out heart problem is a valve that has thickened gradually over a decade of use. A built-in problem is an outflow channel that formed too narrow, a wall that did not close, or a vessel that failed to seal after birth.

The distinction matters because the built-in kind shows itself young, often does not worsen gradually in the way valve disease does, and sometimes has a procedural rather than a medical answer. It also matters for breeding decisions, since congenital defects have a heritable component in several breeds.

Subvalvular aortic stenosis is the classic example. The channel just below the aortic valve is narrowed, so the left ventricle has to generate far more pressure to push blood out. The muscle thickens in response, and in severe cases the blood supply to that thickened muscle cannot keep up during exertion. That is the mechanism behind collapse during play rather than during rest.

Cardiomyopathy is the other term owners encounter. It describes disease of the heart muscle itself rather than the valves or plumbing, and unlike stenosis it is not something the dog is necessarily born with.

Young dogs compensate extremely well, so the signs are intermittent and easy to write off. These are the ones worth taking seriously.

If you think your Bichon has heart problems, the plan is three steps: write down what you have seen and when it started, book a veterinary appointment rather than waiting for the next flare, and take video of the behaviour or symptom before you go — the thing you are worried about rarely happens in the consulting room. Screening in the parents covers skin allergies, patellar luxation, bladder stones.

What the vet visit should produce is a diagnosis and a written plan, not just reassurance: what is being ruled out, what the monitoring interval is, and which signs mean you come back sooner. Ask what the treatment costs across a year rather than per visit, because that is the number that decides whether you are managing this condition or reacting to it.

Between appointments, keep a short log — dates, what you saw, what changed. It is the single most useful thing an owner brings to a follow-up, and for heart problems it is often what separates a clear pattern from a guess.