High blood pressure is an extremely important concern in human medicine.

But what about our pets? 

They don’t live the same high-stress lifestyle that most humans do — and they’re not usually indulging in high-salt or high-fat diets — so why would they develop high blood pressure?

The truth is that hypertension, or high blood pressure, is actually much more common than you’d think in pets.

In people, the most common cause of hypertension is called primary or essential, meaning that there is no underlying disease causing it. Pets, on the other hand, most commonly develop secondary hypertension, which means that it is associated with an underlying medical condition. 

Here’s a look at how the condition is diagnosed in pets — and what veterinarians will do to combat it.

What’s Considered a Normal Blood Pressure for Pets?

Most people are familiar with the normal blood pressure measurement of “120 over 80” in humans, which refers to a systolic blood pressure of 120 and a diastolic blood pressure of 80. The systolic pressure reading designates the highest pressure reached, while the diastolic pressure represents the lowest pressure present in the arteries during a heartbeat cycle. 

Veterinarians do not apply these same values to pets. Since many of them can get easily stressed by a trip in the car or a veterinary visit, a slightly higher normal range of up to “160 over 100” is allowed. And veterinarians most often rely on systolic blood pressure readings, since diastolic pressures are more difficult to obtain in animals because of their small size.

Why Is It So Important to Promptly Diagnose High Blood Pressure in Pets?

When a pet has hypertension, it means that their blood vessels have become too narrow to handle the elevated pressure flow of blood. A helpful analogy is that of a garden hose hooked up to a fire hydrant — the high pressure from the hydrant could cause the hose to contract and potentially pop. The same thing can happen to blood vessels.

Typically, the affected vessels in pets are small, so the actual bleeding, as well as the resulting lack of blood flow to the area, is not noticeable until more significant damage occurs over time. The same can be said of hypertension in humans — there are often no signs of this “silent killer” until major damage is done. 

What Can Happen to a Pet With Hypertension?

Dogs and cats are considered hypertensive and at risk for organ damage when they have systolic blood pressures that are greater than 160 or diastolic blood pressures over 100.

One organ that’s commonly affected by hypertension is the eye. Damage to the back of the eye, called the retina, may result in sudden or gradual blindness in pets. An owner may notice that his pet has dilated pupils, which do not constrict with light, or the pet bumps into objects because of impaired vision or blindness. 

The kidney, heart and brain are also targets of hypertensive damage — worsening kidney problems, heart failure and strokelike signs can result.

There are a number of diseases and health conditions associated with hypertension in pets. Here are some of the key players:

  • Chronic kidney disease
  • Cushing’s disease
  • Diabetes mellitus
  • Obesity
  • Heart disease
  • Hyperthyroidism (cats)

    How Is Hypertension Diagnosed in Pets?

    Pets with any of the previously mentioned conditions, or those showing signs of vision or neurologic problems, should receive regular blood pressure screenings. 

Ideally, older pets should be screened for hypertension whenever they have a physical exam in order to detect problems early. 

Blood pressure in pets is measured using an inflatable cuff that fits snuggly around the leg and a special device that detects blood flow through the arteries. Since pets are significantly smaller than people, stethoscopes are not sensitive enough to properly record blood pressure measurements.

Multiple blood pressure measurements should be taken to allow a pet to adapt to the procedure. Your vet may even recommend a repeat visit in order to confirm the presence of hypertension before prescribing treatment.

What Will My Vet Do to Address the Problem?

There are several medications that are effective for treating hypertension in pets that are designed to dilate blood vessels to help them accommodate the high-pressure blood flow going through them. 

The most appropriate medication depends on the severity of the high blood pressure and the underlying disease that’s present in a pet. Your veterinarian will guide you on the best medication, as well as the best management of your pet’s existing medical condition.

Dr. Donna Spector is a board-certified internal medicine specialist who practices in the northern Chicago area. She also owns a consulting business and provides daily clinical case consultations and continuing education to more than 1,800 primary care veterinarians. See more articles from Dr. Spector here.