Hypertension, also known as high blood pressure, affects pets just as much as it affects people. In people, the most common type of hypertension is known as primary or essential hypertension, which means that high blood pressure is the main disease process. Cats and dogs, on the other hand, rarely develop primary hypertension. Instead, hypertension in pets is usually the sign of another illness and not a problem that exists in and of itself. This is known as secondary hypertension.

What Is High Blood Pressure?
High blood pressure occurs when a blood vessel is too small to handle the pressure of the blood traveling through it. Imagine a firefighter trying to force a high-powered stream of water through a garden hose. The pressure would tear the hose apart. That's the same thing that can happen to a blood vessel if high blood pressure is left untreated.
The retina is at the greatest risk in pets with hypertension. High blood pressure can eventually cause blindness, which is typically the first sign of the condition in pets.
The kidneys can also be affected because they rely on small blood vessels to filter toxins from the blood. These tiny vessels are often among the first damaged by hypertension. Left untreated, hypertension can accelerate kidney diseases far more rapidly than if the condition didn't exist.

What Causes Hypertension?
Hypertension in pets is often the result of other illnesses. Some
possible causes in dogs include kidney disease, adrenal disease,
hypothyroidism (underactive thyroid), diabetes, and pituitary tumors. In cats, the most common causes are kidney disease, hyperthyroidism (overactive thyroid), and heart disease.

Diagnosis of Hypertension
Hypertension can be difficult to diagnose based on clinical signs because many of the associated signs can be attributed to any
number of diseases. If your veterinarian suspects a problem, he or she will measure your pet's blood pressure using a Doppler flow detection system or oscillometry, which are similar techniques to those used to measure blood pressure in people.
Initial blood pressure readings in pets are sometimes artificially high due to the animal's anxiety level in the veterinary clinic (often termed 'white coat hypertension'). Your pet may need to stay a few hours in the clinic until he calms down enough to get an accurate reading.

Treatment of Hypertension
Once your veterinarian identifies hypertension in your pet, he or she will search for the underlying cause of the condition. Often, treating that illness also cures the hypertension.
If that's not enough, medication to treat high blood pressure may be prescribed. Typically, this is a drug that loosens blood vessels to make blood flow more easily. In pets in which high blood pressure has caused eye problems, eye drops may be prescribed as well.
Your veterinarian may also recommend a diet with reduced salt. This would likely mean dry food or a prescription diet.
Pets diagnosed with hypertension should be checked every 2 to 4 months to ensure that their blood pressure is still within the normal range. As in people, pets with hypertension may require medication for life.

POSSIBLE SIGNS OF HYPERTENSION
• Redness in one or both eyes
• Dilated pupils (cats)
• Vision loss
• Deafness
• Circling or head tilt
• Seizures
• Lethargy
• Depression
• Difficulty breathing
• Increased thirst and urination
• Weight loss
• Increased or decreased appetite