Medically Reviewed by Taylor Froiland, PharmD, RPh
Written by Adam McCown, PharmD
As pet owners, it’s a good idea to be aware of what medications your pet is prescribed, why they are being prescribed them, and what the different desired and side effects of the medication may be. In addition to supplying your pet with the highest quality drugs and medications they need in order to become healthy again, our goal at Express Vet Pharmacy is to help you understand what exactly you are giving to your dog or cat and why it is necessary.
Why Is My Dog Prescribed Benazepril?
With that goal in mind, benazepril for dogs is a second-generation angiotensin-converting-enzyme (ACE) inhibitor. That means that it prevents the body from producing angiotensin II, a substance that narrows blood vessels and releases hormones that increase the body’s blood pressure.
This drug is typically used to treat high blood pressure in dogs, and acts as a vasodilator (a substance that widens blood vessels) in the treatment of congestive heart failure (CHF), systemic hypertension, protein losing nephropathies, as well as an adjunctive treatment of chronic kidney failure. Studies in human medicine also indicate that ACE inhibitor drugs like benazepril improve exercise tolerance, improve quality of life, and prolong life in human cases of heart failure.
The effectiveness of benazepril in dogs and other animals (including ourselves) stems from its highly effective ability to relax blood vessels. It accomplishes this relaxation by decreasing the formation of hormones and compounds that serve to induce constriction of the vessels themselves. Benazepril is effective at treating kidney disease and renal insufficiency in dogs and cats because it normalizes glomerular capillary pressure and reduces the systemic blood pressure that can cause those organs problems.
How Benazepril in Dogs Works
According to Pet MD, Benazepril works by inhibiting the angiotensin converting enzyme (ACE), an enzyme that converts angiotensin I to angiotensin II. Angiotensin II acts as a strong vasoconstrictor, meaning it narrows the blood vessels. By inhibiting this enzyme, it prevents the angiotensin II from ever being created and relaxes the blood vessels. This results in lowering blood pressure, lowering the stress on the heart, and reducing fluid build-up in the lungs.
For a dog who has high blood pressure, reducing the stress on both the heart and the blood vessels in paramount. The result of high blood pressure in both animals and humans is that over time, the heart and arteries will become damaged and not function correctly. This can lead to more damage or malfunctioning of the brain, heart, and kidneys.
Side Effects of Benazepril in Dogs
Benazepril in dogs in characterized as being very well tolerated and effective at treating high blood pressure and kidney problems. With that said, however, the following side effects of benazepril have sometimes been reported:
- Nausea
- Appetite loss
- Diarrhea
- Lethargy
- Low blood pressure
- Fever
- Dizziness
- Fainting
- Changes in water intake and urination frequency
In situations where your dog experiences any of these types of side effects, the problem is often solved by giving them the medication with food. However, in some animal patients, these effects are severe enough to stop using benazepril. If your dog experiences any of these side effects then consult your vet as soon as possible so they can determine the best course of action to take.
In some dogs, the medication can result in blood pressure dropping too low as the peripheral blood vessels are dilated. This is the effect that can lead to listlessness and lethargy. Your vet will often solve this issue by adjusting the dose of benazepril. Once again, you should not modify the dose of benazepril for your dog without first consulting your veterinarian.
Precautions and Drug Interactions of Benazepril in Dogs
ACE inhibitors like benazepril are serious drugs that are administered to your dog. For that reason, dogs receiving benazepril should be monitored regularly for arterial blood pressure, renal function, and serum electrolytes. Dogs should not be treated with benazepril if they have pre-existing conditions like hypotension, hypovolemia, hyponatremia, or are in acute renal failure. Additionally, benazepril should be avoided in dogs that are pregnant or lactating.
As we say in all of our articles, when administering benazepril to your dog (or any other medication) it is critically important that you inform your veterinarian of any and all medications and supplements your dog is currently consuming. In some cases, your vet will adjust the dosage of benazepril given that your pet is also prescribed a drug with which a drug interaction is anticipated.
Specific drug interactions with benazepril in dogs that have been reported include the following:
- Potassium-sparing diuretics or potassium supplements may increase the risk of hyperkalemia
- NSAIDs including aspirin should be avoided in animals on benazapril due to an increased risk of acute renal failure
- Concurrent use of benazepril and insulin may increase the risk of hypoglycemia. Animals may require additional monitoring
- Concurrent use of benazepril and lithium may increase lithium levels
Conclusion: Benazepril in Dogs
The dosage of benazepril for your dog will be determined by the veterinarian based on your pet’s specific medical condition, breed, size, weight, body type, as well as other factors. Benazepril has a range of administration options, including manufactured oral tablet form or as compounded into an oral suspension, capsule, chewable, or transdermal gel by a compounding pharmacy.
As always, it is extremely important that you follow your vet’s directions for dosage and administration to the letter. You should not modify dosage or frequency without first consulting them to make sure the change is effective and appropriate. And just to reiterate, benazepril is a powerful medication that can be dangerous if given to your dog improperly.
Benazepril is only available with a prescription from an animal medical professional and can be purchased with a prescription on Express Vet Pharmacy’s website.
