Enalapril for dogs is a medication veterinarians may use to treat congestive heart failure, high blood pressure, kidney disease, or urinary protein loss. Integrative veterinarian Dr. Julie Buzby fills pet owners in on everything they need to know about enalapril—the uses, side effects, dosing information, precautions, and more.
There are many similarities between human medicine and veterinary medicine. For example, many medications that were originally developed for humans also can be safely prescribed for pet health issues. One such medication is enalapril maleate.
What is enalapril for dogs?
Enalapril is a type of prescription medication known as an angiotensin converting enzyme (ACE) inhibitor. Veterinarians most commonly prescribe enalapril to help senior dogs with heart disease, high blood pressure, kidney disease, or high protein in the urine.
Enalapril is FDA-approved for use in humans and dogs. It is available as a tablet, oral liquid, or injectable medication. Most formulations on the market contain the generic drug enalapril maleate. However, enalapril is also available under brand names like Enacard®, Vasotec®, Glioten®, and Lotrial®.
What is enalapril used for in dogs?
As mentioned, enalapril is used to treat a variety of health issues such as congestive heart failure, high blood pressure, proteinuria (i.e. protein in the urine), and chronic renal failure. All of these conditions have one thing in common—activation of a pathway called the renin-angiotensin-aldosterone system (RAAS).
The RAAS system
RAAS is a hormone system that the body switches on when blood volume or blood pressure decreases over a certain period of time. RAAS activation may be triggered by blood loss due to trauma or a ruptured splenic mass in dogs. Severe dehydration, with loss of water and reduction in circulating blood volume, can also activate the RAAS system.
In these cases, RAAS acts as a protective mechanism for the body. It constricts blood vessels to help maintain blood pressure. Plus, it causes the body to retain sodium to boost blood volume, and prioritizes sending blood to the kidneys, brain, and heart. Then once the “threat” to the body is over, the RAAS system goes back to its normal state.
However, chronic conditions like heart failure and kidney disease can also activate the RAAS system. And in those situations, the long-term activation of RAAS can have more negative than positive effects.
RAAS and heart failure
In congestive heart failure in dogs, the heart can no longer pump blood as efficiently as it used to. This decrease in cardiac output (i.e. blood volume exiting the heart) can trigger RAAS activation. The body’s goal is to increase blood volume and blood pressure so that enough blood can make its way through the body to meet oxygen demands. But this has the unfortunate consequences of also:
- Increasing blood pressure, which can damage internal organs
- Further overloading the heart by shunting blood away from the extremities and towards the heart
- Causing fluid retention, which can lead to fluid backing up into lung tissue (i.e. pulmonary edema)
- Leading to heart muscle damage (fibrosis), remodeling, and inflammation
RAAS and kidney disease
The kidneys have a variety of jobs, including filtering out waste products and maintaining sodium and water balance in the body. In chronic kidney failure in dogs, the changes within the kidney and loss of function lead to RAAS activation. This in turn has several negative consequences:
- Retention of sodium and water, which can lead to hypertension in dogs (i.e. high blood pressure)
- Further damage to the structure and function of the kidneys
- Damage to the glomeruli (i.e. filtration unit of the kidney), which leads to protein leaking into the urine
Enalapril inhibits RAAS
As you can see, the RAAS system can be quite damaging in these situations. It makes sense then that finding a way to block the action of RAAS could be helpful. This is where angiotensin converting enzyme (ACE) inhibitors like enalapril come in. In order for this to make sense, we need to discuss the “players” in the RAAS system.
First the kidney releases an enzyme called renin in response to low blood pressure or low blood volume. Then renin converts angiotensinogen (a substance released into the blood by the liver) into angiotensin I. Next, angiotensin converting enzyme (ACE) changes the angiotensin I into angiotensin II.
Angiotensin II is the “powerhouse” substance that helps restore blood volume and blood pressure. It does this by causing blood vessels to constrict, which raises blood pressure and prioritizes sending blood to the vital organs. Plus, angiotensin II leads to the release of aldosterone, a hormone that helps with salt retention. This will increase circulating blood volume by making the body retain water.
ACE inhibitor drugs like enalapril block the enzyme (ACE) that transforms angiotensin I to angiotensin II. As a result, there will be less angiotensin II working in the body. This is beneficial for dogs where the RAAS system is causing more harm than good.
Enalapril and heart disease
In cases of heart disease in dogs where the dog is in congestive heart failure, the enalapril will dilate the vessels in the extremities, which creates more places for the blood to go. As a result, there is less backup of blood near the heart. This takes some of the pressure off the heart and can reduce fluid accumulation in the lungs. Plus, enalapril can reduce the RAAS-induced heart damage.
There have been some studies looking at using enalapril in asymptomatic heart murmur in dogs cases too. Veterinarians hypothesized it could help protect the heart and slow down the development of congestive heart failure. However, an article in the Journal of Veterinary Internal Medicine that looked at the use of enalapril in dogs with asymptomatic murmurs due to mitral valve disease demonstrated that enalapril did not significantly prolong the time to onset of congestive heart failure.
Enalapril and hypertension
In cases of high blood pressure, blocking RAAS with enalapril will reduce sodium and water retention and dilate blood vessels. This can help the blood pressure return to normal. Controlling blood pressure is useful for both kidney disease and heart disease because high blood pressure often leads to more damage to the organs.
In a fair amount of cases, enalapril on its own isn’t sufficient to control blood pressure. In those situations, the vet may also consider adding on a second blood pressure medication.
Enalapril and proteinuria
Another benefit of using enalapril to treat chronic kidney disease is that it can reduce protein loss from the kidneys in the later kidney disease in dogs stages . Normally the “holes” in the blood filtration apparatus of the kidney (i.e. glomerulus) are small enough that proteins can’t fit through. However, chronic kidney disease and other protein-losing disorders such as glomerulonephritis (i.e. damage to the glomerulus) can let protein leak into the urine.
The glomerulus has one vessel that brings blood in and one that brings blood back out again. Enalapril will specifically dilate the blood vessel exiting the glomerulus. This means that the blood traveling through the glomerulus is under less pressure. It enters at the normal flow rate but drains out at a faster rate than usual. This lower pressure in the glomerular vessels will push less protein into the urine.
What is the enalapril dosage for dogs?
Now that you have a better idea of the benefits of enalapril for dogs, let’s talk about the practical details. Your veterinarian will calculate the best enalapril dosage for your dog based on your dog’s body weight.
Then the vet will select the size of enalapril maleate tablets (1 mg, 2.5 mg, 4 mg, 5 mg, 8 mg, 10 mg, 16 mg or 20 mg) or liquid (typically 1 mg/ml) that will best supply the correct dose. This range of tablet sizes and liquid options make it easy to dose small dogs as well as large dogs. Plus, it provides options for dogs who won’t take pills. If your dog is hospitalized, the vet could also give your dog an intravenous (IV) injection of enalapril.
Based on your dog’s situation, the vet may prescribe enalapril on a once or twice-a-day basis. Dogs can take enalapril with or without food. To ensure that your dog’s kidneys stay healthy, the vet will instruct you to ensure you provide plenty of access to clean water at all times.
Enalapril starts working within one to two hours of taking it. However, the effects may not be outwardly obvious to many pet owners right away. Your vet will be able to asses parameters like blood pressure or protein in the urine to get a better idea of whether the enalapril is working.
Missed doses
Do not abruptly stop giving your dog enalapril unless your veterinarian tells you that this is okay. If you accidentally missed a dose, just be sure to give the next one right on schedule. Do not give your pup two doses at once or give extra doses.
Overdose of enalapril
Thankfully, there is a wide safety margin for dosing for ACE inhibitors like enalapril. However, if you think you gave your dog too much enalapril or accidently gave your dog a double dose of enalapril, it is still best to check in with your vet to be safe.
What are enalapril side effects in dogs?
Whenever your dog is taking a new medication, it is important to understand the side effects you should be watching for. The most common side effects of enalapril usage are gastrointestinal symptoms such as vomiting, diarrhea, and loss of appetite. Less common side effects include tiredness (a lethargic dog), fever, skin rash, and weakness.
Other ACE inhibitors like benazepril may cause fewer gastrointestinal effects. For this reason, they might be good options for dogs who don’t tolerate enalapril well.
Risk of kidney failure
As a word of caution, if your dog starts experiencing vomiting and/or anorexia during the first four to seven days of taking enalapril, contact your veterinarian immediately. This could mean that your dog is experiencing kidney dysfunction. Occasionally, enalapril can drop blood pressure a bit too much. This may decrease blood flow to the kidneys to the point that kidney damage occurs.
What are the precautions or contraindications for using enalapril?
Along the same lines, enalapril should not be used in patients with existing acute kidney injuries. There is the risk that it could make the damage worse.
Plus, dogs and cats with acute heart failure should also not take enalapril since enalapril can cause a sharp decrease in blood flow to the kidneys. Since it takes a few days for enalapril to be helpful to the heart, the veterinarian will wait to start it once a congestive heart failure patient stabilizes.
Heart disease
It is fairly common that dogs with chronic heart failure will end up on enalapril plus a diuretic (i.e. water pill) like furosemide. The combination of these two medications can decrease blood flow to the kidneys as a side effect of helping to take the burden off the heart. For this reason, the vet will monitor your dog’s kidney values carefully when using enalapril and furosemide (Lasix®) together.
Veterinarians will also commonly use enalapril with other heart medications like pimobendan (i.e. Vetmedin®) as combination therapy for heart failure.
Liver disease
When a dog takes enalapril, the liver metabolizes it into the active form called enalaprilat. In cases of liver disease in dogs or liver damage, the liver many not be able to metabolize the enalapril. Also, in rare instances, enalapril may cause acute liver damage. The reason for this is unknown.
High blood potassium
Enalapril should be used with caution in pets who are dehydrated and in pets who have already have an increased blood potassium level (i.e. hyperkalemia). Enalapril can further increase blood potassium levels, which may lead to a life-threatening heart arrhythmia. Using enalapril with a potassium-sparing diuretic like spironolactone intensifies that risk.
Anesthesia
Because enalapril can lower blood pressure, it should not be given prior to undergoing anesthesia. The combination of enalapril, and sedatives or anesthetics (which can also lower blood pressure) can lead to a dangerously low blood pressure.
Pregnancy
Pregnant dogs should not take enalapril. Enalapril can reduce fetal kidney function and increase the risk of fetal death.
What are the medication interactions?
Before prescribing enalapril, your vet will also want to know the names of any other medications and supplements your dog is taking. This is important information that can hopefully prevent negative drug interactions.
Depending on the medication, the combination of the two drugs can increase the risk of adverse effects like vomiting and diarrhea. Or it may negatively impact the way the body metabolizes enalapril. The following list of medications, while not comprehensive, should be used carefully (or not at all) when receiving enalapril:
- Anesthetics and opioids
- Antacids (like famotidine)
- Blood pressure medications
- Buspirone (an anxiety medication)
- Benadryl for dogs
- Digoxin (a heart medicine)
- Non-steroidal anti-inflammatories
What sort of monitoring might my dog need?
Like any medication, it is important that you keep tabs on how your dog is doing on the enalapril and contact your vet if you have any concerns. In particular, watch for vomiting, diarrhea, lack of appetite or other signs the enalapril could be making your dog sick.
As you may have gathered, enalapril has the potential to help dogs with chronic kidney disease or congestive heart failure. But it can also occasionally push them into kidney failure or worsen existing kidney disease. For this reason, your vet will want to closely monitor your dog, especially when using enalapril in combination with other drugs.
It is common for veterinarians to recommend checking a patient’s electrolytes, kidney values, and urine protein levels within the first week or two of enalapril usage. After that, he or she might check these parameters every three months in a stable patient. Depending on your dog’s underlying condition, the vet may also want to check your dog’s blood pressure or run a complete blood cell count (CBC).
Final thoughts on using enalapril for dogs
ACE-inhibitors like enalapril can be very helpful for dogs with congestive heart failure, high blood pressure, proteinuria, and chronic kidney disease. However, since side effects from enalapril are sometimes serious, your vet will help you monitor your canine companion closely.
You can trust that your vet has your dog’s best interests in mind. Prior to starting the enalapril, and any time while your dog is on enalapril, don’t be afraid to speak up if you have questions or concerns. Together, you and your vet can help your senior dog various health issues.
What has been your experience with enalapril in dogs?
Please comment below.
Hi..how much enalapril should I give to my 75 lb golden retriever? He has congestive heart failure. Thank you!
Hi Vicki,
I am sorry your Golden is living with heart failure. Unfortunately, without playing a personal role in his medical care I can’t give specific dosing information. When choosing a dose, your vet will take into consideration any other relevant medical issues and what stage of heart failure your pup is in currently. Also, sometimes after starting a medication the dosage has to be adjusted based on the dog’s response. This is all in the hands of your vet and they will guide you through the process. Wishing you both all the best. Take care!
Hi Doc!
My 12 yo, 7lbs Pom was Dx with CHF & heart murmur a couple weeks ago. She was given a combo of Enalapril, furosemide & pimobendan. The symptoms we originally took her in for (all the scary symptoms related to heart conditions), slowly subsided & by day 3 of taking meds, she was almost back to her old self—feisty & always wanting what ur having. There are some differences like wanting to sleep more, bouts of sluggishness, increased thirst & voiding, but decreased bowel movements. They’re minor changes, if I can keep my pup comfortable. I was actually researching private cremations while waiting for her initial Appt. I didn’t think she’d make it thru. I had a check in today & our next big follow up will be in a couple more weeks. I am wondering if this Rx trifecta is something that some pets are given forever? I know there will be routine diagnostics. But can pets generally do well on these meds, indefinitely?
PS- sorry for rambling & thank you for your time!
Hi Suzy,
I am sorry your little pup is dealing with heart disease but glad to hear she responded favorably to the medications. It is possible for dogs to maintain well for months to years with this type of treatment. But eventually the heart will continue to weaken, and the symptoms will return despite efforts to keep them at bay. Your girl is lucky to have you taking such good care of her. It is clear she is dearly loved. Wishing you continued success and many happy days ahead. Bless you and your sweet girl.
Hi how did you give your pup the medication? I know pimobendan is on empty stomach but did you combine all three then food. My dog was just diagnosed and given these meds I forgot to ask if combining is okay
Thank you for providing info and needed comfort to us parents of our beloved pets.
We just realized that our 16 yo male yorkie has missed 3 days worth of taking his Enaprail, refill of prescription should arrive tomorrow – so 4 days ABRUPTLY off his med! He takes 3/4 tab SID.
I have learned suddenly stopping is NOT good by reading articles online.
He seems sluggish for 2 days (now we know why). Advice on dosage to restart? Should I take him into see vet?
Thank you
Hi Wendy,
I understand your worry and concern for your senior guy. I am glad the medication is on its way and am hopeful you can get things turned around quickly. Please reach out to your vet for guidance on how to restart the enalapril. I am not sure what your dog’s original starting dose was, and your vet will be able to give you more specific advice since they know his case details. Wishing you all the best of luck. Take care!
Many thanks for this comprehensive article. My 11 yr mixed breed girl (50lbs) contracted Lymes in 2020, the 3rd tickborne illness she was treated for over her lifetime (ver thick black coat & WV ticks had developed resistance to Frontline. She didn’t tolerate oral meds well, lots of vomiting & lethargy, so controlling for fleas & ticks was done topically, clearly unsuccessfully). Antibiotics did not clear it and she developed chronic Lymes, which has hurt her kidneys, my vet speculates. Her moderate proteinuria is being treated with enalapril. But she also has arthritis and takes galliprant – which greatly improves her comfort and mobility. The contraindications are worrisome, and the bloodwork to try to balance the meds has been extraordinarily expensive. My question is this: can excessive dietary protein worsen proteinuria? She was on grain-free kibble for years, but 3 years ago switched to a brown rice & poultry formula. still, she regularly sneaks 1/4 cup soft cat food, and gets human-grade chicken jerky as a treat. She is a very dependent on routine kind of dog, gets 1.5 hrs offleash hiking daily her whole life. I’ve considered switching her to a high grade food like farmers dog to see if it helps her joints enough to make the galliprant less necessary. She gets bloodwork next week. I’m clear-eyed that she may be declining, and I cared for my mom before her death and witnessed the loss of appetite & interest that comes with old age. I want Leia, my pup, to have the greatest comfort and enjoyment versus longevity. My mom had a fairly miserable longevity- kept alive by her extensive cardiac med regimen but ultimately with utter loss of independence & comfort. I do not want that for my beloved dog. Should I consider changing her diet?
thank you for your time reading this, and for your knowledge. (PS: I went to grade school with a Julie Buzby, decades ago in Southern California. 🙂
Hi Celeste,
Who knew you would encounter two different Julie Buzbys in your lifetime! I think it is great you are searching for ways to improve your dog’s health and extend her life. Diet can definitely affect the amount of protein the kidneys have to deal with. A diet change could be recommended depending on your dog’s current stage of kidney dysfunction. If you were going to switch your dog’s food, then I would encourage you to think about a prescription kidney diet specifically formulated for this exact condition. There are also many other natural ways to help with arthritis pain. Supplements are a good place to start. I will attach links to other articles with more information. Hoping you can find the right combination of treatments to keep Leia happy and living her best life. Bless you both and keep up the good work!
1. Kidney Disease in Dogs: Stages and What They Mean For Your Dog
2. Natural Pain Relief for Dogs: 13 Methods
3. Adequan for Dogs: Don’t Just Treat Arthritis, Slow it Down
4. How to Relieve Arthritis Pain in Dogs: The Ultimate Guide
My 16 year old 5.5 lb poodle started enalapril two months ago for rapid breathing, heart murmur. Did very well with activity, eating but developed a dry cough. She had also just recovered from kennel cough. I recently stopped it because of her coughing all night. Wondering if it would be helpful to restart at 1/2 dose or would she likely cough again.
Hi Mary,
I am sorry your senior girl is having so many issues. Coughing is not a side effect of enalapril as far as I am aware. But coughing can be a symptom of worsening heart disease or could have been left over from the kennel cough your pup had. Is your vet aware your dog is no longer taking the enalapril? I think it would be best to contact your vet and let them know how things have progressed and the changes that have been made. They can guide you in the right direction and decide if the enalapril needs to be restarted and at what dosage. Hoping you can get things straightened out quickly. Wishing you both the best!
My little Yorky started on enalapril about a week ago. At first she did really well but now she’s very lethargic and has no appetite. Also, her urinary output has been decreased because your lack of wanting to drink water. I’m not sure this is the medication for her? I think I will talk to my doctor about changing it up. Thank you.
Hi Debbie,
I agree those symptoms are worrisome and need further investigation. I am glad you are planning to talk to your vet. Hoping your sweet girl is feeling better and praying for a positive outcome. ♥
hello my 8lb Pom that is 16yrs old has been take 2.5 twice daily now a new vet is stating to much. she has staff 6 heart murmur. she is on Lasix and vet.edtin. is that too much?
Hi Christy,
I wish I could give you a specific yes or no, but the answer is it depends! When a veterinarian makes a decision on what dosage to use, they take into consideration may factors including severity of symptoms and response to medication, evidence of unwanted side effects, and how the medication works with or interacts with other treatments also being used at the same time. For some drugs there is even blood work that can be done to determine what amount of the medication is present in the blood stream. So unfortunately, this is something you would need to discuss with your vet as I cannot give specific recommendations. Please let your vet know about your concerns and give them a chance to explain why they wanted to decrease your dog’s enalapril dosage.
Hi Dr Buzby
My 7 year old yorkiepoo eats Hills C/D food for a few years now for urinary issues. Her urine test recently came back showing list of protein in urine. Vet gave her Enalapril for about a month. She finished the meds and 3 days later vet tested urine again and no change. Now get wants to put her back again in Enalapril. If it didn’t reduce numbers why would the Vet prescribe again?
Is there another way to fix this issue?
Thank you so much
Enid Rodriguez
Hi Enid,
I understand your concern about the protein that was found in your dog’s urine. Without speaking to your vet, myself, I can’t know why certain decisions have been made. Have you asked your vet why they want to keep your dog on the Enalapril? If I had to guess, they were probably trying to see if the kidney issues would resolve with just a little bit of help. Since the numbers did not change, they probably want to keep using the medication to maintain as much kidney function as possible. When the kidneys start to struggle, they can benefit from increased blood supply. Enalapril helps to increase the blood flow to the kidneys. There are several things that can be done to treat kidney disease, but you need a diagnosis first in order to choose the best treatment. Here is a link to another article with more information: Kidney Disease in Dogs: Stages and What They Mean For Your Dog
I hope you can find the answers you are looking for and find time to have a much-needed conversation with your vet.
My oldest pup (~17 y/o) is on enalapril plus furosemide. He’s done well on this combination but has lately developed loose stools – not quite actual diarrhea, but more looseness than possibly be good for him.
We’re going to try gradually adding pumpkin, rice, and oatmeal to see if we can get over this. We hate to remove either medication since these are keeping him alive. Also: which one should we remove first? Wish us luck!
Hi Crow,
I understand your concern for your senior pup and these issues with loose stool. Since it is not severe enough to be considered diarrhea and your boy is not straining to defecate, I am not sure I would consider discontinuing one of these medications. Especially since you said they are working well. I would rather have a dog with loose stool than one suffering the symptoms of congestive heart failure or fluid build up. I think the pumpkin is a great idea. Here is a link to another article with more information: Canned Pumpkin For Dogs: A Veterinarian’s Guide
As always please make sure your vet is aware of this issue. They can help you determine what is best for your pup. Hoping you can get things back on the right track. Wishing you and your sweet boy the best.
Hi – great article. We started our Ziggy ( 16 years old! )a few weeks ago. She has developed a dry cough. Is there an alternative medication that vets use?
Kind regards
Hi Theresa,
There are many different medications that can be used in dogs with heart disease. The drug selection is usually made based on the specifics of your dog’s case and stage of disease. Are you concerned that the enalapril is causing the cough? Without examining your dog, myself, I can’t make specific conclusions or recommendations, but I would be suspicious that the heart issue is progressing, and the cough is a symptom of the progression. Please reach out to your vet and let them know about this new symptom. They will be able to guide you through the treatment process and make any necessary changes to your dog’s medications. Best wishes!
I just started giving my miniature schnauzer Chico this medication together with his Veteroyl and Pemibendon. Wish us luck! He will be 14 on April 18th and so far he’s trying to hang in there. He’s been my expensive guy, but I won’t give up on him! 💙 He’s family, we love him ❤️
Hi Fallon,
I hope the addition of the enalapril will help improve your senior guy’s quality of life. Wishing you and Chico the best of luck! Feel free to keep us updated on how things go in the future.
So far my dog hasn’t had any problems and she’s been on Enalapril for quite sometime now and so far she doesn’t take any other meds . I was really scared at first to have to put her on it especially because someone on social media said that’s what they gave her dog and it caused more problems and end up passing. She said they give them smthg that’s supposed to help but it can actually make them worse. I guess like it’s a chance if you want to or not . It was scary coz i love my dog so much and i didn’t want to give her smthg that would make her even more sick. But i realized every dog is different just like people when it comes to medicine. And situations can be different too. So I’m thankful she’s doing alright on it and hope she’ll continue . . I know God really takes care of her for my sake too. Thank you for this great article too i think it’s a must read for anyone who’s having to make that decision like i had too . Unfortunately i didn’t get to read this article during that time when i was trying to decide for my fur baby. Thanks 😊
Hi Barbara,
I am glad your dog has been doing well since starting the enalapril. You are absolutely right that each dog is different, and I am glad you gave this medication a chance. Thank you for sharing your experience with our readers. Best wishes to you both for many happy days ahead!
Thanks! Sasha is still taking it and has been doing well but just the last few days I’ve noticed her coughing that wakes me up sometimes and that concerns me. so I’m thinking i may need to take her to the vet for a check up . She’s been on the medication awhile and hasn’t had any blood work done sense. Other than that she seems well and she wants to eat all the time lol so maybe i should mention that as well. But i found my way back here because I’m wondering if it’s okay to give the Enalapril a couple hours earlier sometimes ? I usually give it 12 hrs apart but there’s times I’ve needed to give it an hour or two hours earlier when i need be somewhere and can’t give it exactly 12 hours apart ? I’m hoping to remember to ask them this question next time i go. Anyway i appreciate your reply . Thank you Have a blessed day !
Hi Barbara,
I am so glad to hear from you again! What a blessing Sasha has been doing well for so many months since starting the enalapril. With the new symptoms you are noticing I agree your girl needs to get examined by your vet. It could be time to add on another medication to her treatment regimen or her enalapril dosage may need to be adjusted a bit. It should not be a problem for you to give her the medication a little early some days. Rarely do I have a client that actually gives the medicine exactly 12 hours apart. You are a unicorn of a client that any vet would be thrilled to have! Praying everything will check out ok at her appointment. Wishing you both the best and keep up the good work!