Enalapril for Dogs: A Medication to Treat Heart Failure

If your dog has congestive heart failure or protein in their urine, your veterinarian may prescribe enalapril (Enacard, Vasotec). Enalapril relaxes blood vessels, reducing strain on the heart and limiting protein loss in the urine. Side effects are typically mild and may include loss of appetite and diarrhea.

Read on to learn more about this medication, including how it works and its potential side effects. 

Enalapril for dogs at a glance

What is enalapril for dogs, and how does it work?

Enalapril belongs to a class of medications known as angiotensin-converting enzyme (ACE) inhibitors. As an ACE inhibitor, enalapril relaxes blood vessels in the body, which decreases stress on the heart. This makes it a good option to treat congestive heart failure in dogs.

Enalapril also affects the kidneys. By dilating blood vessels within certain parts of the kidneys, enalapril decreases the rate at which they filter blood. While this can have negative impacts, it can also help treat conditions such as protein in the urine.  

What is enalapril used for in dogs?

Enalapril is primarily used to treat dogs with congestive heart failure (CHF). It is not typically used alone. Instead, it is typically one of several medications taken by dogs with CHF. 

There are many causes of CHF in dogs, including: 

• Mitral valve insufficiency

• Dilated cardiomyopathy (DCM) 

• Patent ductus arteriosus (PDA)

• Atrial septal defect 

• Heartworm disease

In reality, almost any form of progressive heart disease can ultimately lead to CHF. When the heart is no longer able to effectively pump blood throughout the body, CHF is the result. Although medication cannot cure CHF, enalapril and other medications can manage your dog’s symptoms to improve their lifespan and quality of life. 

Less commonly, enalapril is used to treat proteinuria (protein in the urine). Protein should remain in a dog’s bloodstream after being filtered by the kidneys. But some dogs leak protein from their kidneys. This leads to low blood protein levels. Because enalapril decreases kidney filtration, it can decrease the amount of protein lost in the urine.

How is enalapril dosed and given for dogs?

Your veterinarian will determine the best enalapril dosage for your dog. This dosage will be based on your dog’s body weight, the condition requiring treatment, and any underlying diseases your dog may have. 

Enalapril is typically given by mouth once or twice daily in a tablet or oral solution. It can be given with food or on an empty stomach. 

Follow your veterinarian’s instructions to reduce the risk of side effects. 

What are the common side effects of enalapril in dogs?

The most common side effects of enalapril for dogs are gastrointestinal (GI) effects. These GI effects may include:

• Decreased appetite

• Nausea

• Vomiting

• Diarrhea

Giving your dog enalapril with a full meal can decrease the risk of GI effects. 

Your veterinarian will probably recommend regular monitoring while your dog is taking enalapril. Blood tests are usually performed 1 to 2 weeks after starting enalapril, and then every 3 to 6 months long-term. With regular monitoring, side effects can be found quickly. If your vet finds a problem early, they can change the dosage or medication before it does more harm. 

What are the most serious risks of enalapril for dogs?

The most serious risk of enalapril for dogs is its effects on the kidneys. Enalapril slows kidney filtration, which can be a problem in dogs with pre-existing kidney disease. 

Dogs who are taking both enalapril and a diuretic are also at an increased risk of kidney failure. Enalapril’s impact on the kidneys can also cause an increase in blood potassium. 

Enalapril may also lower your dog’s blood pressure, making them lethargic.

Does enalapril interact with any other dog medications?

Enalapril can interact with a number of other medications. Interactions can increase the risk of side effects or decrease the effectiveness of one or both medications. 

Use caution when combining enalapril with: 

• Blood pressure medications

• Steroids (such as prednisone)

• Diphenhydramine (Benadryl)

• Diuretics

• Insulin and other diabetes medications

• Nonsteroidal anti-inflammatory drugs (NSAIDs)

Your veterinarian should be familiar with all the medications your dog is taking. These include prescription medications, over-the-counter medications, and nutritional supplements. This way, your veterinarian can work to reduce the risk of medication interactions. 

What should you do if your dog misses a dose of enalapril?

If you forget to give your dog a dose of enalapril, give them the missed dose as soon as you remember to do so. Then, wait the recommended amount of time before giving your dog their next dose. Do not give a double dose of enalapril. 

Why trust our experts?

Written by:

Catherine Barnette, DVM

Catherine Barnette, DVM, is a small animal veterinarian with 14 years of experience providing preventive care, medical workups, and surgical services in a number of general veterinary practices. She also served on her county's board of health for several years and taught biology laboratories for college students.

Edited by:

Renée Fabian, MA

Renée Fabian is the senior pet health editor at GoodRx. She’s worked for nearly 10 years as a journalist and editor across a wide range of health and well-being topics.

Reviewed by:

Ghanasyam Bey, DVM

Ghanasyam Bey, DVM, is from Cleveland, Ohio, and attended Princeton University for undergraduate studies. After a year of biology research at Duke University, he attended Ohio State College of Veterinary Medicine.

Our editorial standards

Meet our experts