Enalapril is an angiotensin-converting enzyme inhibitor (ACE inhibitor) which prevents the body from producing angiotensin II, a hormone which causes an increase in blood pressure. In technical terms it achieves this function by acting on the Gq protein in vascular smooth muscle cells and on the Na/H exchanger in the kidneys to reduce the amount of water in the blood. These actions lower blood pressure which helps to keep vital circulatory components safe from damage. The drug is approved by the FDA and also goes by the name Enacard or Vasotec.

What’s the risk of hypertension?

Hypertension can sometimes be an asymptomatic condition (meaning there are no symptoms), but when left untreated is able to cause damage to aspects of the circulatory system including major blood vessels and the heart itself. It also heightens the risk of developing kidney problems, heart attack and stroke.

Dogs with hypertension may display symptoms such as circling, loss of sight, diminished sense of direction, seizures, weakness, eye or nose bleeds and the presence of blood in urine.

What’s The Dosage?

Note: Only give enalapril to your dog if you have permission from your vet. Use of the drug in unsuitable dogs could lead to symptoms of hypotension including dizziness and fainting.

The standard dosage given to dogs is 0.25 mg/lb to be administered once daily. Tablets come in many strengths but the most commonly used veterinary form comes as 1, 2.5, 5, 10 or 20 mg pills with an injectable (IV) form prepared at 1.25 mg/mL.

A chart showing the canine dosage of enalapril

Adjunctive treatment with furosemide is common in cases of congestive heart failure. It is often given along with medicines such as Vetmedin, an inodilator created specifically for dogs.

The injectable IV form is often used when there is no possibility of oral administration, or when effects are needed immediately (in an emergency situation for example).

Is my dog’s blood pressure reading high?

Dogs will usually only be treated with this medicine if their readings are abnormally high. See the table below for a list of readings and the risk level associated with them where the first number represents systolic pressure, and the second number (after the slash) represents diastolic pressure.

Note: Normal readings can differ greatly between breeds, this chart is only a rough guideline. The normal range for different breeds can be found here.

An example range is shown on the table below.




150/99 – 159/95High NormalNone.
160/199 – 179/100HighTreatment advised.
180/120Extreme HighEmergency treatment needed.

Your vet may use a number of methods to take your dog’s blood pressure including the Doppler Flow method and more commonly the Oscillometric method. Both will require the placement of an inflatable cuff onto your pet. It’s important to keep your pet still while their reading is taken. The process may be repeated by the vet up to 6 times for accuracy, with nervousness taken into account.

How Safe Is It?

It’s safe to give the medicine to most dogs with hypertension or heart failure though extra care must be taken when treating those with congestive heart failure (CHF). It may also be administered to increase survival rates following heart attacks. Despite its relative safety when used correctly under veterinary guidance, the drug can interact with many commonly used medicines, and can lead to problems when given to those with poor kidney function (a reduction in the dose is advised in this case), blood abnormalities, low blood sodium levels, cerebrovascular or coronary insufficiency, systemic lupus erythematosus and other collagen vascular diseases.

You should only administer this medicine if you have been instructed to do so by your vet. Enalapril should only be given when really needed, as those with normal (or even normal/high) blood pressure who receive the medication could suffer hypotension as a result. It should not be given to pregnant pets as ACE inhibitors can cause various problems and deformities to offspring.

FDA Status: The drug is FDA approved for use in pets under application number 141-015 as the branded form Enacard, sold as “Enacard Tablets For Dogs”.

Safety Guidelines

To safely use this medicine you must first visit your vet for approval and prescription. You will also need a professional diagnosis and shouldn’t diagnose your pet yourself based on perceived symptoms of the condition. After your dog has been diagnosed, enalapril has been prescribed for use and you have been given a plan of treatment you will be able to begin administering the drug, but first tell the vet about:

  • Other medicine you are giving your dog
  • Other medical conditions your dog suffers from

Never exceed the dosage recommended by your vet without ringing him/her first, even if your pet doesn’t appear to be experiencing a relief of symptoms.

Note: Do not administer diuretics in conjunction with enalapril or just before starting treatment with the drug. Doing so can lead to hypotension.

What Is It Used For?

This drug’s effects on blood pressure and water levels make it a helpful medicine in the treatment of various illnesses. Most often it is used to treat hypertension. Some other conditions which this drug may help includes:

  • Heart failure
  • Kidney problems
  • Forms of nephropathy
  • Heart attack (recovery)

Kidney problems which enalapril is sometimes used to treat are usually those caused by diabetes and scleroderma.

Side Effects

Several side effects are associated with the use of enalapril. These can be worrying if you aren’t sure what to expect. During treatment the following adverse effects could occur:


  • Dizziness
  • Drowsiness
  • Coughing


  • Rashes
  • Vomiting
  • Diarrhea
  • Hypotension *


  • Allergic reaction
  • Chest pain
  • Kidney problems
  • Lowered urine output

* This can result in additional symptoms such as dizziness, loss of balance, blurred vision, rapid/irregular heartbeat and fainting. Call the vet immediately if you suspect your dog is suffering from hypotension. It is usually a result of overcorrection, or giving the medicine to a dog who doesn’t need it. To lower the risk of hypotension it’s advised that you stop administering any diuretic medication before the first dose.

You should always call the vet if you suspect your dog is suffering a bad reaction to the drug.


Enalapril overdose may be spotted by symptoms such as fainting, headaches, slow heartbeat, drowsiness and infrequent urination (or lower volume urination). If you suspect an overdose, call the vet immediately.