There is no cure for MMVD so treatment is aimed at controlling the associated clinical signs and slowing the progression to congestive heart failure. Sadly, as this condition is progressive, signs of disease can worsen over time. Treatment usually comes in the form of oral medications which are taken at regular intervals at home. Dosage will be adjusted based on your pet and how their condition progresses, with many dogs ending up on multiple treatments. These medications include:
Diuretics (known by some as ‘water tablets’) help to control the formation of oedema, which is fluid that has leaked out of the blood into areas like the lungs. They work by helping the kidneys to excrete (get rid of) more salt into the urine, which in turn encourages more water to be excreted too. This helps to reduce the amount of fluid flowing through the dog’s blood vessels, reducing blood pressure and fluid retention. Symptoms associated with excessive fluid leakage in MMVD such as an increased breathing rate and effort, are usually improved.
Your vet may suggest regular blood tests to ensure your pet’s kidney function and electrolyte levels are stable.
ACE inhibitors help to improve the signs associated with congestive heart failure and can improve life expectancy. They work by stopping blood vessels from constricting and reducing blood pressure, which in turn can help to reduce the amount of fluid leakage that occurs.
Again, regular blood tests are usually recommended to ensure your pet’s kidneys are functioning appropriately while on this medication.
Inodilators are positive inotropes, which means they help the heart to beat more effectively. It also helps blood vessels to dilate (get wider) reducing blood pressure which in turn helps to reduce fluid leakage into places like the lungs. Pimobendan may be used in some dogs who are pre-clinical (before symptoms of heart disease are evident) but with MMVD and heart changes confirmed on echocardiography and X-rays. Some studies indicate that this can help delay the onset of congestive heart failure and improve lifespan.
Other treatment options include:
Changes in diet can help your pet, alongside any prescribed medications. Firstly, being overweight or obese can make problems worse for dogs with MMVD. So, ensuring your pet stays slim and has regular moderate exercise can help.
An ideal diet for a dog with heart failure includes the following:
Some of these nutrient adjustments could help slow the progression of MMVD and should be beneficial in other forms of heart disease as well (Laflamme, D.P., 2022). Your vet will be able to recommend a diet for your dog. It is important to use commercially prepared food, rather than trying to do a home-cooked diet, unless you are working under the supervision of a veterinary nutritionist.
Traditionally MMVD has been medically managed as success rates in cardiac surgery in dogs were poor. However, advances in this field have been made, so valve replacement surgery is a possibility in some cases. However, only a handful of specialist referral clinics offer this treatment. The chance of successful recovery from surgery is currently between 50 and 83% at The Royal Veterinary College, London. The surgery is not without risk, and the costs can be prohibitive for many owners too, however, your vet can arrange a referral if you would like to explore this option.