Dobermann Pinscher’s Special Hearts & DCM
Dilated cardiomyopathy affects 50% of male Dobermanns and 33% of females and it is common in other breeds of dogs such as Boxers and Irish Wolfhounds. It appears typically between 6 and 8 years of age.
What happens to our gentle friends hearts is that the heart chambers get bigger (dilated) and the strength of the contractions decreases. If you imagine the Circulatory System as a complex plumbing structure it is easy to understand that when the pump is not doing its job properly the whole system fails. Because the heart is not able to pump the blood that is coming from the lungs, the pressure in the veins there increases and fluid leaks into the lungs. That is called (left sided) congestive heart failure.
The problem with DCM, particularly in Dobermanns, is that in addition to low cardiac output (weak pump) that occurs when the disease is advancing there is another problem, which can start early and can be a lot more acute: the presence of arrhythmia’s, these are changes in the electrical conduction in the heart (a bit of electrics now…) that lead to a loss of the rhythm and coordination of contractions of the different chambers of the heart.
The first clinical signs of DCM may vary and include respiratory problems, exercise intolerance and syncope (fainting), and unfortunately in 40% of cases the first clinical sign is sudden death. Up to half the Dobermanns diagnosed with DCM die suddenly due to this arrhythmia’s and that is why some cardiologists recommend using Holter monitors to diagnose acute disease before the obvious clinical signs appear. This is a device that is attached to an animal for 24 hours and records the heart activity, being able to pick up the early signs and therefore enabling early treatment. You can see an example of a canine holter here.
Diagnosing this condition can be challenging and ideally different tests need to be done including a Holter monitor, ECG-electrocardiogram- to pick up the arrhythmia, an ultrasound scan (to measure the chambers and see how strong the heart is pumping) as well as chest x-rays (to see if fluid is leaking into the lungs and how big the heart and the bloods vessels are).
The treatment may be complicated and tailored to the individual patient, and it normally includes drugs to treat both the plumbing (increase the heart strength and get rid of the fluids in the lungs) and the electric problems (anti-arrhythmia drugs such as beta blockers). In Dobermanns the drugs to prevent the Ventricular Arrhythmia’s may be the most important as the need to prevent sudden cardiac death is more acute.
The life expectancy after diagnosis is only a few months, particularly in Dobermanns, but if picked up in the “occult” early phase it can be a lot longer and treatment of arrhythmia’s may be necessary in this early phase.
This article was reproduced by kind permission of Andre Escudeiro-Vieites LV MRCVS
Andre is a partner at Quinton Vets4Pets in the heart of England.