Mitral valve disease (MVD) affects many small and medium-sized breeds, and makes up about 75% of all the heart disease we see in dogs. In the 2020s, we know that we can bring a quality of life benefit to dogs at two main stages of MVD: dogs with no signs but cardiac enlargement (known as stage B2) and dogs with heart failure (stage C). For most dogs in stage B2, we recommend medical treatment using pimobendan (Vetmedin®). In dogs with advanced B2 or stage C, three main treatment options exist.

Should we add Entresto to standard medical therapy?

Before this year, two studies (2018 and 2021) looking at a combination drug called Entresto (sacubitril & valsartan) were published. Both were well-designed, with a control group of untreated dogs, but despite this they showed conflicting results. In one, 30-days of treatment reduced heart size but did not affect the neurohormonal changes associated with heart disease. In the other, no benefit on heart size was detected, but some improvement in neurohormonal levels was seen. Neither study was designed to show any impact on survival. In 2026, a large case series of 50 dogs was published which reports long-term use of Entresto in dogs with MVD and heart failure signs. In this publication, all dogs had lived for over 6-months with heart failure, on standard treatment, before Entresto was prescribed. There was no control group of untreated dogs, and heart failure status at the time of Entresto being prescribed is unclear and not uniform across the study group. Although the longevity of dogs in the recent study parallels those treated with standard medical therapy, the survival time is reported by the authors to be longer than we expect for standard treatment. Over time, some dogs treated with Entresto developed evidence of deteriorating kidney function, and some dogs did not tolerate the drug well because of gastrointestinal side-effects. Monitoring of non-cardiac body systems is required over time.

Because of the limitations of the study design, the most we can infer from the 2026 Entresto publication is that the drug appears to be tolerated at doses of 15-20 mg/kg twice daily in dogs, over months of treatment. We cannot conclusively say that it improves survival in heart failure for dogs with MVD. However, based on the survival data provided, at 2-years after the diagnosis of heart failure, survival rate appears to be around 30%. This is encouraging and we appreciate that most dogs with advanced MVD will not have time for the ideal long-term study data to become available. The price of Entresto at standard, twice daily dosing for a 10kg dog is approximately £770 per month (at 20 mg/kg). We would be happy to prescribe Entresto for dogs with heart failure who need more than 6 mg/kg/day furosemide (or equivalent torasemide dose) to control their clinical signs. 

What are the potential benefits of heart surgery for MVD?

Mitral valve repair is probably the best hope for long-term reduction in mitral regurgitation severity. It appears to have the best 2-year survival rate (80-90% for heart surgery, vs. 15% for standard medical treatment and at-best 30% with addition of Entresto), but it is associated with short-term risk of complications, and a larger financial commitment up-front. Open-heart surgery on bypass is more invasive and carries a greater risk of major surgery-associated complications. In contrast, TEER surgery has a lower risk of short-term complications because it is less invasive, but the reduction in mitral regurgitation with TEER would be expected to be lower than with open-heart surgery. Some dogs are not suitable for TEER, because of their size or individual valve anatomy, in which case open-heart surgery would have greater flexibility to get good results. We do refer dogs on for bypass surgery if their TEER assessment with us suggests that would be a better option.

What can we expect for dogs undergoing TEER?

Although TEER is a relatively new procedure in dogs, we have come to understand the balance of risk and benefit. Data published in 2025 from an experienced centre suggest:

• Around 95% of dogs are expected to be discharged alive and well, with reduced mitral regurgitation severity.

• Around 40% of dogs can have their diuretic medication stopped completely after surgery, and almost all have a reduction in dose. 

• The major risk of TEER is a partial detachment of the clamp from the mitral valve leaflets, which can cause severe heart failure signs which are almost always fatal.

Although we are experienced heart surgeons at BVS, our TEER programme only began in  September 2025. This means that our complication rate for the first 12-months may be higher than once we become more experienced at the surgery. We arranged support from experienced TEER surgeons from Europe and Asia for our cases, and generally have good results. We have also worked alongside the Royal Vet College, to maximise the benefit of their experience with mitral valve anatomy for dogs undergoing bypass surgery. After 20 cases (16 at BVS, 4 supporting the RVC; end-May 2026), we have experienced two surgery-associated deaths because of device-complications. We have identified key steps to minimise the risk of the same events occurring again, and implemented these for follow-up cases. The remaining 18/20 dogs survived surgery and experienced a good reduction in mitral regurgitation severity.

Whilst open-heart surgery has the best hope of eliminating mitral regurgitation completely, TEER is a good alternative option which has a positive outcome for most dogs. Our experience shows us that if we can achieve our target reduction in mitral regurgitation severity (to 30% or below), dogs can have a reversal of cardiac remodelling and a reduction in heart size as early as 4-weeks post-surgery. Many of these dogs can tolerate lower diuretic doses and a notable improvement in clinical signs.

Planning a TEER referral to BVS

If you already have seen a veterinary cardiologist, they will need to send us the images from your dog’s heart scan. We will review these, to see if there are any “red flags” which mean that TEER is unsuitable – we do not want you to have a wasted journey if we can avoid it. If things look suitable, we will then arrange a telephone consultation with you to discuss the practical details of TEER surgery and what to expect from recovery.

If you wish to, we will then organise a face-to-face consultation and a trans-oesophageal echo scan (TOE) under a light anaesthetic. This will allow us to make a detailed assessment of the mitral valve and accurately measure the size of device that we will need. Then, we will be able to discuss the balance of potential risks and benefits with you, particular to your dog’s valve and their anatomy, so that you can make the best decision possible. The cost of the TOE (£600) will be refunded from the procedure cost if your dog does go for TEER surgery with BVS.

If you do not have a cardiologist, but want to investigate whether TEER is a good option for your dog, then please ask your primary vet to make an appointment for you to see us, and we can begin the process with a face-to-face consultation and a specialist level heart scan. The cost of this would be £1,122 (our standard fee for new cases).