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Lisinopril for cats: Uses, dosages, and safety

Lisinopril lowers blood pressure in cats with heart failure
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By | Updated on Feb. 25, 2025 Medically reviewed by Emma Ryan, DVM
Picture of cat: Is lisinopril safe for cats

Key takeaways

  • Lisinopril is used to treat congestive heart failure in cats.

  • The standard lisinopril dosage for cats is 0.25–0.5 mg/kg given once daily.

  • The most common side effects of lisinopril in cats are diarrhea and vomiting.

    • Do not give lisinopril to cats that have had an allergic reaction to ACE inhibitors.
In this article:

What is lisinopril used for in cats?

Veterinarians primarily use lisinopril to decrease blood pressure in cats with heart failure. Lisinopril belongs to a family of drugs called angiotensin-converting enzyme inhibitors (ACE inhibitors). These drugs block an enzyme that synthesizes angiotensin II, a hormone that constricts blood vessels and raises blood pressure. 

Congestive heart failure

Congestive heart failure (CHF) is a condition in which the heart doesn’t pump sufficient blood to the body and can’t maintain blood pressure in the veins. It’s usually the result of serious heart disease. The body compensates for heart failure by increasing the size of the heart and retaining water and sodium to increase blood volume. Heart failure and the body’s compensations for it are a downward spiral that eventually leads to death.

When veterinarians treat heart failure in a cat, they try to lower blood pressure, increase the heart’s output, and eliminate fluid buildup in the body. Drugs are used to accomplish each of these goals: ACE inhibitors to lower blood pressure, heart drugs such as pimobendan to improve the heart’s performance, and diuretics such as furosemide to address fluid retention. Although the heart drug digoxin is often used in dogs with heart failure, it may not be effective in cats.

When ACE inhibitor therapy is necessary, veterinary professionals usually choose enalapril or benazepril because they’re well-studied in dogs (but not in cats). Although lisinopril is not commonly used, it has the potential advantage of once-daily dosing. 

High blood pressure

Veterinarians may use lisinopril to treat high blood pressure in cats, but it’s unlikely. There are no published dosages, so the drugs of choice are benazepril and enalapril. 

Is lisinopril safe for cats?

Lisinopril has not been widely studied in cats, but veterinarians believe it is safe based on clinical experience. It is contraindicated in any cat that has had an allergic reaction to ACE inhibitors.

The drug is used cautiously in cats with kidney disease, low sodium, blood disorders such as lupus, or problems with blood flow to the heart or brain. Cats with severe heart failure will require extra monitoring when taking lisinopril. 

Lisinopril may harm unborn kittens.

Veterinarians do not know if lisinopril is present in cat milk or can affect nursing kittens.

Side effects of lisinopril in cats

The most common side effects of ACE inhibitors in small animals are:

  • Diarrhea
  • Vomiting
  • Decreased appetite

If any of these side effects persist or worsen, contact the veterinarian.

More serious but rare side effects of ACE inhibitors in small animals include:

  • Low blood pressure (hypotension)
  • High potassium (hyperkalemia)
  • Kidney dysfunction
  • Weakness
  • Allergic reactions

If the cat shows any signs of an allergic reaction, such as excessive itching, redness, hives, wheezing, difficulty breathing, or swelling of the lips, face, or paws, contact the veterinarian.

Interactions of lisinopril with other pet meds

To avoid potential drug interactions such as low blood pressure, tell the veterinarian about all the drugs and supplements the cat is given, particularly:

Lisinopril dosage for cats

The standard dosage for feline heart failure is 0.25–0.5, given every 24 hours. Veterinary literature does not have a recommended dosage for feline hypertension.

Lisinopril is not FDA approved for use in cats, so veterinarians prescribe lisinopril “off-label.” Pet owners will have to use tablets made for people or tablets prepared by a compounding pharmacy. Lisinopril tablets formulated for people come in dosage strengths of 2.5 mg, 5 mg, 10 mg, 20 mg, 30 mg, and 40 mg. 

A lisinopril oral solution is available for people and is sold under the brand name Qbrelis. A compounding pharmacy or veterinary pharmacy can specially prepare a liquid version of lisinopril made with oil. 

Can cats overdose on lisinopril?

Veterinary literature does not specify a maximum dose of lisinopril for cats. To prevent an overdose, do not exceed the prescribed dose.

Veterinarians consider a lisinopril overdose in a small animal as any dose higher than 20 mg per kilogram of body weight. In small animals, the most common clinical signs of a lisinopril overdose are:

  • Lethargy
  • Vomiting
  • Rapid heart rate

The most serious problem caused by an ACE inhibitor overdose is low blood pressure, a potentially life-threatening problem. When blood pressure gets too low, common signs include:

  • Fainting
  • Confusion
  • Lethargy
  • Weakness
  • Changes in urination

Contact an ASPCA Animal Poison Control Center or a veterinary hospital if a cat has ingested too much lisinopril. 

Can I give my cat lisinopril every day?

When lisinopril is prescribed to a cat, caregivers will give daily doses for months or years. Any cat with heart failure will probably take daily medications like lisinopril for the rest of its life. 

How to give your cat lisinopril

Caregivers typically give their cat one dose of lisinopril daily, but the cat with heart failure will probably need several other medications administered throughout the day. All of these medications are critical, so do not forget doses. 

  • Follow all the veterinarian’s instructions.
  • Do not change the dose until talking to the veterinarian.
  • Lisinopril doses can be given with or without food.
  • If you don’t know how to administer tablets to a cat, ask a veterinary professional to demonstrate the correct procedure.
  • Lisinopril oil-based suspension may need to be shaken before measuring a dose. Read the instructions.
  • For liquid lisinopril, measure doses only with the calibrated oral syringe or dropper provided by the veterinarian or pharmacist.
  • If a dose is missed, give it as soon as possible. If it’s almost time for the next dose, do not give the cat the missed dose. Give the next dose as scheduled. Never give two doses to make up for a missed dose.
  • Do not discontinue lisinopril treatment until talking to the veterinarian. 
  • Store lisinopril tablets at room temperature protected from moisture, excessive heat, and freezing. 
  • For Qbrelis or lisinopril oil-based suspension, follow the storage instructions included with the medicine or printed on the label. 

Lisinopril alternatives for cats

Lisinopril is not commonly prescribed to cats. The ACE inhibitors of choice for treating feline heart failure or high blood pressure are enalapril and benazepril. Besides these two ACE inhibitors, other alternatives to lisinopril include:

Summary

Lisinopril is considered a safe treatment for feline heart failure, but some veterinary professionals question its effectiveness. Adverse effects are minimal. Give doses once daily with food.

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