Heart Murmurs in the Bichon Frise: How to Read the Grade

An innocent puppy murmur often does, usually by four or five months as the dog grows and the heart rate settles. A murmur that first appears in an adult or senior Bichon does not go away, because the underlying valve change that causes it does not reverse.

Loosely, and with real exceptions. Grade tracks with severity across large groups of dogs, but individual animals break the pattern in both directions. A grade two dog can have an enlarged heart and a grade four dog can have a normal one, which is exactly why imaging exists.

Low-grade murmurs are genuinely hard to hear. A panting dog, a noisy waiting room, a fast heart rate from stress, or simply a different stethoscope can hide a grade one. If two opinions disagree, ask for a listen when the dog is calm rather than assuming one vet was wrong.

It can, and this is one of the most useful reasons to investigate. Knowing the heart's size and function lets the anaesthetist choose drugs and fluid rates appropriately. A documented murmur is not a reason to skip dental treatment, which a Bichon is likely to need.

Ask the breeder for the grade, the age at which it was heard, and whether it has been re-checked or imaged. A soft murmur documented once at eight weeks with a follow-up plan is very different from an unexplained loud one. Get your own vet's opinion before the sale completes.

A stressed dog with a racing heart is harder to assess and can produce turbulent flow sounds. Anaemia and fever can also generate a murmur that resolves once the underlying issue is treated, which is why bloodwork sometimes accompanies the first assessment.