Benazepril for Dogs: Side Effects, Dosage and Monitoring
By Dr. Zubair Khalid, DVM, MS, PhD ·
Most dogs tolerate benazepril well, and the most common benazepril for dogs side effects are mild stomach upset, sleepiness, or a temporary drop in appetite. Serious problems are uncommon but possible, especially when the dose is too high or when kidney function and blood pressure are not checked on a schedule. This article is educational and is not a substitute for veterinary diagnosis or treatment.
Quick Answer
- Benazepril is an ACE inhibitor used for heart disease, high blood pressure, and protein loss through the kidneys in dogs.
- The dose is calculated by your veterinarian from your dog's weight and health status, and it is usually given once daily by mouth.
- Mild side effects include vomiting, diarrhea, tiredness, and reduced appetite. These often fade as the body adjusts.
- Bloodwork and blood pressure checks before treatment and during treatment are what keep the drug safe.
- Call your veterinarian the same day if your dog vomits repeatedly, refuses food, seems weak, or faints.
What Benazepril Is and What Veterinarians Use It For
Benazepril belongs to a drug class called angiotensin-converting enzyme inhibitors, or ACE inhibitors. In both people and dogs, these drugs are prescribed for heart disease to quiet down a hormone system called the renin-angiotensin-aldosterone system, or RAAS [1]. When the heart or kidneys are under stress, that system overreacts and raises blood pressure, holds onto salt and water, and puts extra strain on already damaged tissue. Benazepril interrupts that cycle.
Veterinarians reach for benazepril in three main situations.
Heart disease. It is commonly part of a heart failure treatment plan, often alongside drugs like furosemide and pimobendan. One large review of dogs with myxomatous mitral valve disease at ACVIM stage C compared dogs on two, three, or four heart drugs and found no significant difference in the rate of cardiac death between the groups [2]. That does not mean benazepril is useless. It means the drug works as part of a plan, and your veterinarian weighs the whole picture when choosing what to prescribe.
Kidney disease and protein in the urine. When kidneys leak protein, benazepril can help lower that loss. A study of dogs with protein-losing nephropathy found that ACE inhibitors like benazepril were used to manage proteinuria and blood pressure, and that combining an ACE inhibitor with another blood pressure drug reduced protein loss further [3]. This is why benazepril kidney dogs are often monitored with urine tests, not just blood tests.
High blood pressure. Benazepril blood pressure dogs are a common search for a reason. Lowering blood pressure protects the eyes, brain, heart, and kidneys from the damage that sustained hypertension causes. Your veterinarian may use benazepril alone or with another medication depending on how high the pressure is.
How Benazepril Works
Benazepril itself is not the active drug. The liver converts it into benazeprilat, which is the form that does the work in the body [1]. That conversion matters because it explains why the drug takes a little time to build up its full effect and why dosing schedules are set the way they are.
Once active, benazeprilat blocks the enzyme that produces angiotensin II, a powerful vessel-narrowing hormone. With less angiotensin II, blood vessels relax, blood pressure drops, and the kidneys release less protein into the urine. The RAAS has more than one pathway, and benazepril's effect on these pathways is dose dependent, meaning higher doses produce larger changes in the measured hormone markers [1][4]. This is exactly why your veterinarian wants to pick the dose carefully instead of simply using the highest number.
Benazepril for Dogs Dosage: Who Decides and How It Is Given
The dose is not a one-size number
Your veterinarian calculates the dose from your dog's body weight, kidney values, blood pressure, and the other medications your dog takes. In research settings, doses of 0.125 mg/kg, 0.25 mg/kg, and 0.5 mg/kg by mouth have been studied in dogs, and the higher doses produced stronger effects on hormone markers [1]. A combination product containing benazepril at 0.25 mg/kg with spironolactone at 2 mg/kg once daily has also been studied [4]. These are research doses, not a prescription for your dog. Never adjust the amount on your own.
Giving the medication
Benazepril is given by mouth, usually once daily, with or without food. Many owners hide it in a small treat or pill pocket. If your dog has a sensitive stomach, giving it with a meal can help. Follow the label exactly, and do not split, crush, or double up unless your veterinarian tells you to.
Missed doses
If you miss a dose, give it when you remember, unless it is almost time for the next one. In that case, skip the missed dose and go back to your normal schedule. Do not give two doses at once to catch up. If you are unsure, call your veterinary clinic and ask.
Benazepril for Dogs Side Effects
Most dogs on benazepril have no obvious problems. When side effects do appear, they are often mild and short lived. The table below covers what owners most often report and what to do about it.
| Side effect | How common or serious | What to do |
|---|---|---|
| Vomiting or diarrhea | Common, usually mild | Give with food, watch for blood or repeated episodes |
| Tiredness or lethargy | Common early in treatment | Note the pattern, call if it persists beyond a few days |
| Reduced appetite | Common, usually mild | Offer favorite foods, call if your dog skips meals |
| Weakness or wobbliness | Less common, can be serious | Call your veterinarian the same day |
| Fainting or collapse | Uncommon, serious | Treat as an emergency |
| Increased drinking and urination | Possible, needs checking | Report it so kidney values can be reviewed |
| Swelling of the face, hives, trouble breathing | Rare, serious | Emergency care right away |
| High potassium or rising kidney values | Found on bloodwork, not visible at home | Keep monitoring appointments |
Because benazepril lowers blood pressure, some dogs run low, especially during anesthesia or when other blood pressure drugs are on board. A large review of 390 anesthetized dogs identified risk factors for hypotension during anesthesia, which is one reason your veterinarian will want to know your dog takes benazepril before any procedure [5]. Tell every clinic and every surgeon about this medication.
If your dog takes other long-term medications, the side effect patterns can overlap. It helps to know what to expect from each drug, whether that is gabapentin, seizure medication, or antibiotics. Keep a simple log of symptoms and dates. It makes phone calls to your clinic far more useful.
What owners say in benazepril for dogs reviews
Online reviews are a mixed bag, and that is expected. Many owners report their dogs seem more comfortable, breathe easier, or have more energy. Others describe vomiting, picky eating, or a dog that seems flat for a week or two. Reviews cannot tell you whether a drug is working, because the real proof shows up in blood pressure readings, urine protein tests, and heart exams. Use reviews for emotional support, not for medical decisions.
Who Should Not Take Benazepril and What Interacts With It
Benazepril is not right for every dog. Your veterinarian will weigh the risks if your dog has:
- Dehydration or is actively vomiting
- Poor kidney function with unstable values
- Low blood pressure
- A history of reactions to ACE inhibitors
- Pregnancy or breeding plans
Drug interactions matter too. Benazepril is often combined with other heart or kidney medications, and some combinations need closer monitoring. Diuretics like furosemide can add to blood pressure lowering and fluid loss. Nonsteroidal anti-inflammatory drugs can stress the kidneys when used with benazepril. Potassium supplements and potassium-sparing diuretics can push potassium too high. Combining an ACE inhibitor with another blood pressure drug has been shown to reduce proteinuria further in dogs with protein-losing nephropathy, but that combination also needs careful watching [3]. Always give your veterinarian a complete list, including supplements and over-the-counter products.
Overdose and When to Call for Help
An overdose of benazepril can cause a sharp drop in blood pressure, weakness, fainting, vomiting, and dangerous changes in kidney values and potassium. If you think your dog swallowed extra pills, do not wait for symptoms. Call your veterinarian or an animal poison control service right away. Have the bottle with you so you can read the strength and the number of tablets involved. Do not induce vomiting unless a veterinary professional tells you to.
Limitations and When to Contact a Veterinarian
This article cannot tell you whether your dog's dose is right or whether a new symptom is caused by benazepril. Only your veterinarian can do that, using your dog's exam, bloodwork, and history.
Call the same day if your dog vomits more than once, refuses food for a full day, seems weak or wobbly, drinks and urinates much more than usual, or just seems off in a way that worries you.
Go to an emergency clinic now if your dog faints, collapses, has trouble breathing, develops swelling of the face or hives, or cannot stand.
Keep routine visits for bloodwork and blood pressure checks. These appointments are how problems get caught before your dog feels sick. Bring your medication list and note any doses you missed.
Frequently Asked Questions
How long does it take for benazepril to work in dogs?
Some effects, like lower blood pressure, can begin within days, while changes in urine protein and heart workload take weeks to show on tests. Your veterinarian will usually recheck values after a set period instead of judging success by how your dog looks at home. Give the medication consistently and keep those recheck appointments.
Can I stop benazepril suddenly if my dog seems fine?
No, do not stop it on your own. These medications support the heart and kidneys continuously, and stopping suddenly can let blood pressure and hormone activity climb back up. If you are worried about cost, side effects, or anything else, call your veterinarian and talk through the options first.
Does benazepril cure heart disease or kidney disease in dogs?
No, it manages these conditions but does not cure them. It reduces strain on the heart and kidneys and can slow some of the damage that high blood pressure and protein loss cause. Treatment plans usually combine medication with diet, weight management, and regular monitoring.
Is benazepril the same as enalapril for dogs?
They are in the same drug class and are used for similar purposes, but they are different medications with different dosing. A study of dogs with protein-losing nephropathy grouped benazepril and enalapril together as ACE inhibitors when comparing treatment approaches [3]. Do not swap one for the other without your veterinarian's guidance.
Can benazepril be given with other heart medications?
Yes, it is often prescribed alongside other heart drugs, and research has looked at two, three, and four drug combinations in dogs with stage C mitral valve disease [2]. More drugs do not automatically mean better outcomes, so your veterinarian will tailor the plan to your dog. Report any new medication, supplement, or change in behavior at every visit.
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- Benazepril for Dogs: Weight-Based Dosage
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References
- Dose-response of benazepril on biomarkers of the classical and alternative pathways of the renin-angiotensin-aldosterone system in dogs. Scientific reports, 2023.
- Comparison of the effects of dual, triple, and quadruple medical therapy on cardiac death in a retrospective cohort of dogs with myxomatous mitral valve disease at American College of Veterinary Internal Medicine stage C: is more necessarily better?. Journal of the American Veterinary Medical Association, 2025.
- Effect of telmisartan, angiotensin-converting enzyme inhibition, or both, on proteinuria and blood pressure in dogs. Journal of veterinary internal medicine, 2021.
- Dose-exposure-response of CARDALIS® (benazepril/spironolactone) on the classical and alternative arms of the renin-angiotensin-aldosterone system in healthy dogs. Journal of veterinary internal medicine, 2025.
- Risk factors for hypotension in anaesthetized dogs: a retrospective analysis of 390 cases. Frontiers in veterinary science, 2026.