Living with a dog with CHF or How long is a piece of string

Primrose was diagnosed with a heart murmur as she past five years old. Heart murmurs in Cavaliers pretty much most of the time indicate a level of prolapsing of the Mitrial Valve. Some Cavaliers this may never progress to cause them any problems, but for far to many. They will progrees to have Mitrial Valve Disease and end up in Heart Failure (HF) or Chronic Heart Failure (CHF) and ultimately die from this condition. 
As CavalierHealth.org explains about Mitral Valve Disease, 'Heart mitral valve disease (MVD) is the leading cause of death of cavalier King Charles spaniels throughout the world. MVD is a polygenetic disease which statistics have shown may afflict over half of all cavaliers by age 5 years and nearly all cavaliers by age 10 years, should they survive that long. MVD has been found to be 20 times more prevalent in CKCSs than in the average dog breed.  It is estimated to affect 10% of the entire dog population, but at a much older age of onset than for CKCSs. In the United States, out of 300,000 dogs, 5% died of MVD while 50% of the cavaliers died of MVD.
​MVD is a degeneration of the heart's mitral valve, one of four sets of valves in a dog's heart. A dog's heart valves' leaflets must open and close tens of thousands of times a day to maintain uni-directional blood flow through the heart.  When the valves open, they direct blood flow forward to where it is supposed to go, and when they close, they prevent blood from going backward to where it is not supposed to go. The mitral valve is located between the left atrium and ventricle.As the mitral valve degenerates, the valve no longer fully closes after each pumping action, allowing some blood to flow backwards through them from the ventricle back into the atrium. As the condition worsens, more and more blood is able to backflow through the valve as the leaflets of the valve begin to flail. In the final stages, the valve’s struts (chordae tendineae) sometimes break, causing the valve to collapse completely. In most dogs affected with MVD, the disease seldom progresses to heart failure. The estimates have varied from 20% to 30% of all dogs diagnosed with MVD eventually going into heart failure. However, MVD usually results in heart failure in the CKCS.
Heart failure (HF) or congestive heart failure (CHF) is a condition where the heart is still working, but it can't pump enough blood to fully meet the dog's body's needs.  HF is determined by its symptoms, which include high rates of breathing (respiratory rates), exercise intolerance, shortness of breath (dyspnea), increase in respiratory effort, and/or fainting.  The term "congestive" refers to the heart's dysfunction causing increased blood pressure in the veins and capillaries, leading to fluid buildups in the heart and eventually in the lungs (edema) or elsewhere (effusions).
About 10% of all dogs suffer from some form of heart disease. Mitral valve disease is the most common heart disorder in older dogs of all breeds. However, in the cavalier King Charles spaniel, the prevalence of MVD is about 20 times that of other breeds. Also in cavaliers, the onset of the disease typically is much earlier in the life of the dog. It has been reported that, once diagnosed, mitral valve disease is much more rapid in cavaliers than in other breeds, possibly reaching a life-threatening stage within as little as 1 to 3 years, rather than the average 3 to 5 years.'
Primrose started to show signs of Chronic Heart Failure (CHF) just over 9 years old and she will be 10 years old this August. Drugs have improved greatly for this stage and let's make no bones about it. We are not giving curative medications for CHF. The medications now are purely palliative care. There are though surgical options, now available if you have very very deep pockets, and one has to question the ethics of putting a dog through such intrusive procedures. Dogs don't live with the same fears we do. Having lived with a human with CHF and dogs with CHF. I know for humans CHF can be incredibly frightening to live with, but for a dog being less knowing of their predicament. They are living in the moment unaware of each heart beat or not.
Primrose has done well on the medications so far, but we have had blips, as her condition deteriorates. Anyone who has looked after a dog through the later stages of MVD will know only to well the ground I am walking at the moment. Blips are when we get a build up of fliud on the lungs, and as I've been here a few times before, with other Cavaliers, I have got good at picking up the signs. An increase in ​Respitory Rate at rest is a big indication that something is going on and medications may need tinkering with and also coughing increases and/or coughing is productive.
With Primrose just increasing her diuretic tablets have been enough to get her back on track, so far. She is though I know now on on borrowed time and each time we have a blip, we wonder is this now the final diviation. She is still so full of live, for a dog, so near to death. She relearns her limits each day, as she bombs off to bark at that annoying leave in the hedge. That has been her nemisis for as long as we both care to remember, and as she comes bombing back, slows up, and then for a moment, you think, "Is this it." As you see her wobble, look a bit faint, and she sits for a while. I run over to check her. She then gets up and carries on at a more measured pace, that I doubt will only last until she has to warn us of that leave again. Living with a dog with CHF, is living with several lengths of string, and you don't know how long any of them are.