High Blood Pressure in Cats
Feline hypertension, or high blood pressure, has many causes. In 13-20% of cases there is no underlying cause or disease, and this is called primary hypertension. More often cats will have a disease process that causes the high blood pressure. Some common causes of hypertension include chronic kidney disease, hyperthyroidism, diabetes, age, and hyperaldosteronism. We can also see elevated blood pressure that is due to stress, or white coat syndrome. Therefore, we will often recheck blood pressures in cats after we get an initial increased result.
Increased blood pressure can be detrimental to many different organ systems in the body. Below is a list of some of the damage hypertension causes in cats (called end organ damage).
- Eyes: blindness due to retinal detachment, retinal bleeding
- Heart: arrythmias, heart murmurs, left heart enlargement, heart failure
- Kidney: damage and loss of kidney function
- Brain: depression, disorientation, seizures, gait abnormalities
The goal in treating high blood pressure in cats is to minimize the damage to these organs.
When do we test blood pressure?
- Any cat that has any of the symptoms listed above
- Any cat with chronic kidney disease, diabetes, or hyperthyroidism
- All cats under anesthesia
- Any senior cat defines as over 7 years old
- Any sick cat
How do we test for high blood pressure?
At the Cat Hospital of Media, we use what is called indirect blood pressure readings. Most commonly, we use what is called a Doppler. The doppler uses a crystal to listen to the pulse, much like a nurse would use a stethoscope to get our blood pressure. A pediatric blood pressure cuff is used around one of the legs or tail. This is non-invasive and well tolerated by our patients. The doppler is what we will use during your cat’s appointment.
While your cat is under anesthesia, we use an oscillometric blood pressure monitor. This type of monitor automatically gives us readings and we monitor the blood pressure consistently during your cat’s procedure.
Diagnosing high blood pressure
When measuring blood pressure in cats, we never take just one reading. We will take multiple readings and evaluate your cat’s level of stress. If we get consistently high readings, we may recommend you bring your cat back for a recheck before we prescribe any treatment. We need to make sure stress is not causing the increased blood pressure.
- <150 mmHg is normal blood pressure
- 150-159 mmHg is borderline, low risk of end organ damage
- 160-179 mmHg hypertension, moderate risk for end organ damage
- >180 mmHg severe hypertension, high risk of end organ damage
Your veterinarian may prescribe one of the following medications for high blood pressure.
- Amlodipine: Amlodipine is a calcium channel blocker. This is the most prescribed medication for high blood pressure in cats. Amlodipine comes in pill form, but we can have it made into a liquid or treat if pills are not working for you and your cat. Most cats will take this once or twice daily.
- Telmisartan: Telmisartan is an angiotensin receptor blocker and was approved for use in cats in 2018. It is a liquid sold under the brand name Semintra. Dosing starts at twice daily and is reduced to once daily in most cases.
- Benazepril: Benazepril is an ACE inhibitor. It is not used as a primary drug for high blood pressure, but it may be added if additional medication is needed to control hypertension.
- Atenolol: Atenolol is a beta blocker and may be used in cats.
Once treatment begins, your veterinarian will recheck your cat’s blood pressure every 3-5 days until it is normal. We will adjust the mediations as needed. Once the blood pressure is well controlled, we will monitor the blood pressure every 6 months.