Benazepril for dogs: Uses, dosage, and side effects

In this article:

• What is benazepril used for in dogs?
• Safety
• Dosage
• Alternatives

In this article

• What is benazepril used for in dogs?
• Safety
• Dosage
• Alternatives

Veterinarians use the blood pressure drug benazepril hydrochloride (brand name: Lotensin) to treat congestive heart failure, kidney disease, and high blood pressure in dogs. Not only is benazepril safe and effective, but it is also a critical component of treating heart failure and protein-losing kidney disease. In both cases, benazepril treatment significantly slows the progress of these diseases and increases the dog’s survival time.

RELATED: Save up to 80% on benazepril

What is benazepril used for in dogs?

Veterinarians use benazepril as a blood-pressure-lowering drug in dogs with congestive heart failure, protein-losing kidney diseases, and hypertension. As an angiotensin-converting enzyme inhibitor (ACE inhibitor), benazepril works by blocking the body’s production of angiotensin II, part of a complex of hormones (the renin-angiotensin-aldosterone system or RAAS) that controls blood pressure, blood volume, fluids, and electrolytes in the body. Angiotensin II (the word means “blood vessel tightener”) tightens muscles in the blood vessels, decreasing their width and increasing blood pressure. Blocking the production of this hormone widens blood vessels and reduces blood pressure.

Congestive heart failure

Congestive heart failure (CHF) is a condition in which the heart cannot pump enough blood to the body. It’s a condition that steadily worsens over time. This can be due to several causes, but the most common in dogs is due to disease of the heart valves. Healthy heart valves should work as one way valves to direct blood through the heart. When aging or diseased heart valves allow blood to leak, blood pools within the heart and is not pumped efficiently around the body. This blood pooling within the heart can cause the heart muscle to stretch and become weak, worsening the efficacy of the heart’s action as a pump. 

The veterinary treatment of congestive heart failure involves three main types of drugs. 

• Diuretics, which make the dog urinate more, reduce the excess fluid retention that builds up in the body because of heart failure. Furosemide is the diuretic of choice for heart failure in dogs. 
• A drug called pimobendan strengthens heart contractions, so the heart pumps more blood. 
• ACE inhibitors like benazepril lower blood pressure in the peripheral arteries. This does two things: it lowers arterial blood pressure, so the heart doesn’t have to work so hard to pump blood. It also increases blood pressure in the veins, which means that more blood enters the heart. 
• Some dogs may get a fourth drug called digoxin which is used to control heart rate.

The ACE inhibitors enalapril and benazepril are the most frequently prescribed drugs to dogs with heart failure. They are highly effective and safe, and they significantly increase the length of the dog’s life.

Proteinuria and kidney disease

Proteinuria simply means there is too much protein in the urine relative to creatinine, a common waste product in urine. Proteinuria can be a temporary problem—for instance, some drugs cause proteinuria as a side effect. However, it can also be a warning sign of serious and progressive kidney disease.

In particular, proteinuria is a potential sign of glomerular or nephrotic disease, conditions that affect the filtration systems in the kidneys. The job of the kidneys, after all, is to take waste, electrolytes, and water out of the blood and eliminate it through the urine. 

That job is done by little structures in the kidneys called nephrons made up of arteries, veins, and little tubes. The most important parts of the system are the glomeruli, bundles of tiny and very thin peripheral arteries. These arteries are so thin that blood pressure is enough to push water, electrolytes, and waste through the artery walls. But it’s usually not strong enough to push very many proteins through those walls.

Dogs with nephrotic or glomerular disease are steadily losing these glomeruli. The body compensates by increasing blood pressure through glomeruli that are still working. The increased blood pressure pushes more water and waste through the artery walls. It also pushes a lot more proteins through those walls, too. That’s what causes proteinuria.

The increased blood pressure also damages those fragile arteries, so these protein-losing kidney diseases worsen over time. ACE inhibitors like benazepril work directly on peripheral arteries like the glomeruli. By reducing blood pressure, benazepril reduces protein in the urine and also protects these fragile structures from further damage. As with heart failure, benazepril or enalapril treatment significantly lengthens the lifetimes of dogs with protein-losing kidney disease. Of the two, benazepril is the preferred ACE inhibitor for canine kidney disease because its blood concentrations are more predictable in dogs with kidney disease than enalapril.

High blood pressure

Benazepril is a common treatment for hypertension in dogs. It is usually the first drug that a veterinarian will try. If the drug brings blood pressure under control, vets will continue benazepril treatment. If it doesn’t, the veterinarian will turn to other drugs either a replacement for benazepril or an add-on.

The problem with ACE inhibitors like benazepril is that they’re not very powerful, making them unsuitable for very high blood pressure. Amlodipine and hydralazine may be the most consistently effective blood pressure drugs in dogs.

Is benazepril safe for dogs?

As in people, benazepril is a safe drug that usually doesn’t cause significant side effects or serious problems. The only dogs that cannot safely take benazepril are dogs that have had an allergic reaction to benazepril or a similar drug like enalapril or captopril.

Veterinarians use benazepril cautiously in dogs with:

• Low sodium
• Lupus
• Collagen vascular disease
• Blood disorders
• Severe heart failure

Benazepril may not be safe when given to a pregnant or nursing dog. There is evidence it can cause birth defects in unborn puppies, but veterinarians are unsure how it affects nursing puppies. 

Side effects of benazepril in dogs

The most common side effects of benazepril in dogs are:

• Vomiting
• Diarrhea 
• Loss of appetite

If these side effects or the underlying condition worsen, contact the dog’s veterinarian.

More serious but rare side effects include:

• Low blood pressure
• High potassium
• Kidney dysfunction
• Hypersensitivity reactions

Contact a veterinarian if you notice any signs of an allergic reaction such as:

• Rash
• Fever
• Tiredness

Interactions of benazepril with other pet meds

Make sure the veterinarian knows about all the drugs and supplements the dog is taking. Benazepril has some significant drug interactions the veterinarian may wish to avoid including:

• Other blood pressure drugs
• Diuretics
• Insulin and oral diabetes medications
• Potassium supplements or potassium-sparing diuretics
• Nonsteroidal anti-inflammatory drugs (NSAIDs)

Except for potassium supplements, pet parents should be able to give their dogs vitamins, herbal remedies, and even CBD. However, make sure to tell the veterinarian about all these other remedies including how much is given to the dog and when.

Benazepril dosage for dogs

The standard benazepril dosage for dogs is 0.25–0.5 mg per kilogram of body weight taken by mouth every 12 or 24 hours.

Plumb’s Veterinary Drug Manual lists the following dosages:

• For adjunctive treatment of heart failure: 0.25–0.5 mg/kg given by mouth once a day
• For proteinuria: 0.25–0.5 mg/kg given by mouth once or twice a day
• For hypertension: 0.25–0.5 mg/kg given by mouth once or twice a day

Benazepril is not FDA approved for use in companion animals, but pet parents can choose between human formulations or compounded veterinary formulations. Veterinary formulations come in tablets as small as 1 mg, but human formulations start at 2.5 mg. Compounding pharmacies can also supply benazepril as a capsule or oil-based liquid (sometimes with meat flavoring) for easier dosing.

Can dogs overdose on benazepril?

The prescribed dose should be considered the maximum dosage. Do not give a dog more benazepril than instructed.

Dogs can have problems if they take too much benazepril. The principal worry is low blood pressure which could be life-threatening. If a dog has had too much benazepril, call the ASPCA Animal Poison Control Center or a veterinarian. Veterinary professionals may need to monitor the dog for several hours.

Can I give my dog benazepril every day?

Benazepril is a long-term daily treatment. Dogs with heart failure, chronic kidney disease, or high blood pressure may need to take the drug for the rest of their lives. 

As in people, benazepril is safe to give to dogs. It has minimal side effects and is unlikely to cause serious problems if a veterinarian regularly sees the dog and performs blood tests.

How to give your dog benazepril

Benazepril is a relatively easy pill to give a dog because it is small, even at large doses. If pills are a challenge, a compounding pharmacy can mix up an oil-based liquid for easier dosing. 

• Only give a dog benazepril if it has been prescribed by a veterinarian.
• Give the doses exactly as prescribed. Do not increase or decrease the dose until talking to the veterinarian.
• Do not miss doses. Veterinarians use benazepril to hold back the progress and complications of chronic and serious conditions.
• Benazepril does not cause withdrawal effects or require doses to gradually decrease when it’s time to stop, but do not stop giving the dog benazepril doses unless instructed by the veterinarian.
• Benazepril can be given with or without food. If doses are causing digestive system problems, try giving the dose with a meal or snack.
• If you don’t know how to give a dog tablets or capsules, ask a veterinary professional to demonstrate the proper technique. 
• Benazepril oil-based liquid may need to be shaken before measuring a dose. Read the instructions.
• Always use the calibrated oral syringe or dropper that comes with the liquid to measure doses.
• If you forget a dose of benazepril, give it when remembered. If it’s almost time for the next dose, skip the missed dose and give the next dose at the regular time. 
• Benazepril tablets should be stored at room temperature. Read the instructions when storing benazepril oil-based liquid.

Benazepril alternatives for dogs

Benazepril is a preferred treatment for serious veterinary conditions: heart failure and protein-losing kidney disease. If it doesn’t work, veterinarians will try other ACE inhibitors. The most likely alternative is enalapril, but other treatment options include lisinopril, ramipril, and captopril. 

Veterinarians do have other treatment options if ACE inhibitors are a problem. For kidney disease, they can try a similar family of drugs called angiotensin II receptor blockers (ARBs). Guidelines for heart failure in people suggest ARBs or Entresto (sacubitril-valsartan) if ACE inhibitors can’t be taken. The last has only been used experimentally in dogs. 

For blood pressure problems, veterinarians usually start with ACE inhibitors like benazepril or enalapril unless blood pressure is too high. If it works, there’s no reason to change the medication. If it doesn’t work, they will add or switch to other blood pressure drugs like calcium channel blockers, ARBs, beta blockers, or alpha-1 blockers. They may also add a diuretic such as spironolactone or a thiazide diuretic.

For heart failure and kidney disease, natural or alternative remedies are not considered effective substitutes for medications. The most effective complementary treatments for canine hypertension are a healthy diet and maintaining a healthy weight.

Summary

When used as directed, benazepril is safe to give to dogs to treat heart failure, kidney problems, and high blood pressure. Side effects are minimal, but treatment will require that the dog be regularly checked by the veterinarian.