Hi Electrocute:
Here is some

Hi Electrocute:

Here is some information from Small Animal Cardiovascular Medicine:

“Doberman pinschers.

Doberman pinschers have a subclinical period, usually between 2 and 4 years, during which they have echocardiographically detectable myocardial failure but no clinical signs.¹⁸ However, in some dogs the disease stabilizes for several years.¹⁹Female Doberman pinschers tend to be older (median age = 9.5 years) than male dogs (median age = 7.5 years) at the time their myocardial failure becomes severe enough for them to go into heart failure.²⁰ Although it appears that males and females are equally affected, more males develop heart failure and die of their disease than do females.²⁰ In one study, of 66 Doberman pinschers that either died from heart failure or died suddenly, 55 (83%) were males. Doberman pinschers, like cats, often appear to develop heart failure acutely. The presentation is often so acute that an owner thinks that someone has poisoned the dog. Instead, dogs hide their clinical signs well until heart failure is severe and only show obvious clinical signs when heart failure is severe. Doberman pinschers may be diagnosed with DCM at almost any age and most commonly present in heart failure between 2 and 14 years of age.²⁰ The time course of the disease appears to be accelerated in Doberman pinschers that develop echocardiographic evidence of the disease at less than 2 years of age and more prolonged when it develops after 6 to 7 years of age.²¹ Approximately 75% are between 5 and 10 years of age at the time they die.²¹A litter of 8 Doberman pinscher puppies has been reported in which 6 developed and died of DCM between the ages of 10 days and 17 weeks of age.²² Parvovirus was ruled out as a cause of DCM in this litter. Attenuated wavy fibers were identified, which suggests the cause of DCM in this litter was different from that found in older Doberman pinschers.

Ventricular arrhythmias are an extremely common finding in affected Doberman pinschers with one study reporting their presence in 92% of affected dogs.²³ They most commonly originate from the LV.¹⁸ The number and the complexity of the ventricular arrhythmias increase as the disease progresses. One investigator reported a study of 129 Doberman pinschers with no clinical signs of disease.²⁴ Of these, 87 (57%) had a shortening fraction between 30% and 34% and had no or fewer than 50 ventricular premature depolarizations on a 24-hour ECG recording (Holter monitor). All of these dogs were alive and healthy 3 years later. Thirty-four dogs had a shortening fraction less than 25% and had more than 100 ventricular premature depolarizations per 24 hours. Eight had a shortening fraction between 25% and 29% and 50 to 100 ventricular premature depolarizations per 24 hours. Of these 42 dogs, 21% died suddenly (n = 9) and 62% died of heart failure (n = 26) within 3 years. Shortening fraction is determined by both end-diastolic and end-systolic diameter. When looked at individually, an end-systolic diameter in an average sized Doberman pinscher greater than 38 mm or an end-diastolic diameter greater than 46 mm is said to be diagnostic of DCM.¹⁹ In any sized Doberman pinscher it is thought that an end-systolic diameter greater than 41 mm or an end-diastolic diameter greater than 48 mm is diagnostic of DCM.¹⁸ Obviously the increase in diastolic size is secondary.

In addition, the presence of more than 50 ventricular premature depolarizations within a 24-hour period on a Holter monitor recording is indicative of DCM in Doberman pinschers.²⁵ The type of arrhythmia appears to be important. All of the dogs with complex ventricular arrhythmias (pairs of ventricular premature depolarizations, runs of ventricular premature depolarizations, and periods of nonsustained ventricular tachycardia) in one study died suddenly, presumably from the ventricular tachyarrhythmia degenerating into ventricular fibrillation.²⁶ Large numbers of single ventricular premature depolarizations did not appear to predict sudden death. However, in a more recent report by the same author, even complexity of a ventricular arrhythmia did not predict sudden death, because many dogs that died suddenly and many dogs that went on to develop heart failure had complex ventricular arrhythmias.⁴ Only the presence of sustained (greater than 30 seconds) ventricular tachycardia predicted which dogs would die suddenly in this report. Approximately 30% of Doberman pinschers are in atrial fibrillation at the time they are diagnosed with heart failure.²⁰

When the shortening fraction decreases to less than 15%, dogs with DCM can go into heart failure.⁴  It is extremely unusual for a dog with DCM in heart failure to have a shortening fraction greater than 15%, and they are commonly less than 10%. Consequently, the diagnosis of DCM should always be questioned in a dog that is in heart failure and has an accurately measured shortening fraction greater than 15%. Although dogs can theoretically have both DCM and primary mitral regurgitation (usually myxomatous mitral valve disease), this appears to be uncommon. More often, large-breed dogs with primary mitral regurgitation develop secondary myocardial failure and present in heart failure with a shortening fraction between 20% and 40%. Most of the Doberman pinschers we see with primary mitral valve disease and myocardial failure do not have ventricular arrhythmias present on a Holter monitor.

Once they are in heart failure, dogs with DCM have both a poor short-term and long-term prognosis despite adequate medical therapy. They commonly present in fulminant heart failure that can be difficult to manage. Consequently, they may die shortly after presentation. These dogs are also commonly euthanized once the owners are made aware of the poor long-term prognosis. Most symptomatic Doberman pinschers die within the first 3 months after diagnosis. Somewhere between 30% and 50% die suddenly during this stage, while the remainder die of CHF.¹⁸ The median and mean survival times have been reported to be 10 and 6 weeks.^20,27 Approximately 25% are dead within 2 weeks of presenting in heart failure, 40% are dead within 4 weeks, and 65% are dead within 8 weeks. Survival of Doberman pinschers with DCM has been reported to correlate inversely with the degree of myocardial failure, as measured by end-systolic diameter.²⁸ Doberman pinschers that present in both left and right heart failure have a worse prognosis (median survival time = 3 weeks) than those that have left heart failure alone (median survival time = 7.5 weeks).²⁰ Doberman pinschers in atrial fibrillation have a median survival time of 3 weeks. Occasionally (about 10% of the time) a Doberman pinscher with DCM will stabilize and do well clinically for a longer time, sometimes up to a year. Box 20-2 presents a case example of a Doberman pinscher with dilated cardiomyopathy. Pimobendan appears to improve survival. In one small study median survival was 50 days in Doberman pinschers with DCM on conventional therapy while it was 329 days on pimobendan.^{29 “}

This dog is probably right on the edge for developing CHF. 

If no arrythmia then I would be inclined to start this dog on Pimobendan. I would keep the Diuretics in reserve. I am not certain about the Ace Inhibitor. I will let the experts weigh in on this.