Blood-pressure measurements have been a standard in human medicine for many years. Due to recent advances in blood-pressure measurements for our pets, hypertension (i.e., high blood pressure) is being diagnosed more frequently during their yearly health examinations.

Your pet's blood pressure may be measured using a Doppler flow detection system or oscillometric methods, both similar techniques to those used in your doctor's office. Initial readings may be high because of the pet's stress and anxiety (affectionately termed "white-coat hypertension") in unfamiliar surroundings, and may be reduced by a few quiet hours in the veterinary clinic.

Hypertension in pets usually indicates an underlying kidney or heart disease, diabetes or feline hyperthyroidism. Over time, hypertension damages vital organs including the eyes, brain, heart and kidneys. Pets with hypertension may experience a sudden loss of vision and/or deafness. Neurological signs may include circling, a head tilt or seizures. But there are a growing number of cases, particularly in cats, where no underlying cause is found. Signs associated with an underlying disease such as heart or kidney disease are more subtle and may include lethargy, depression, difficulty breathing, increased thirst and urination, weight loss, and increased or decreased appetite. Bleeding from the nose may also occur.

Dr. Anthony Carr, Diplomate of the American College of Veterinary Internal Medicine and associate professor at the Western College of Veterinary Medicine, University of Saskatchewan in Canada, stresses that blood pressure should be checked routinely on all geriatric cats as well as dogs, as well as cats at risk due to a previously diagnosed disease such as kidney failure. "Some patients will show obvious signs of hypertension but often hypertension is silent," says Carr.

Dr. Christine Wilford, a private-practice veterinarian at Cat's Exclusive Veterinary Hospital in Shoreline, Wash., describes an unusual presenting symptom. Samantha, a 15-year-old female spayed grey tabby cat was brought in for examination because she was howling. On a hunch, Wilford measured her blood pressure and found it was high. Samantha was sent home on amlodipine, an antihypertensive medication commonly used for cats. After taking amlodipine, not only had Samantha stopped howling but she was playing like a kitten again. Her blood pressure was normal when rechecked four days later. Wilford has seen positive results in other geriatric cats treated with amlodipine for high blood pressure

Wilford sees hypertension in almost 25 percent of the geriatric cats she treats. "I'd say maybe 20 (percent) to 25 percent of those kitties over 13 years of age, those with unexplained dilute urine, renal failure and hyperthyroidism have mild to severe hypertension when I determine their pressures."

"My own cat Fuzzy, a 16-year-old calico kitty had kidney disease and was losing her hearing" explains Dr. Sandy Wright, DACVIM. "I did not want her losing vision due to hypertension with kidney failure." Wright consulted with Dr. Jerry Woodfield, DACVIM (cardiology) in Seattle. "We measured her blood pressure and she was hypertensive. Fuzzy also was placed on amlodipine and her hypertension resolved without a negative affect on her kidney function."

Blood and urinalysis tests help determine the underlying causes of hypertension. These pets may be referred to a veterinary ophthalmologist or cardiologist in addition to treating the underlying causes of hypertension.

Veterinarians have an array of new antihypertensive medications to control hypertension. Special diets may be required and treats high in salt should be avoided. As in man, blood pressure will need to be monitored to tailor the medications to the individual pet.

Prognosis is good for treating hypertension if caught early. Pets that experienced a loss of vision may have their vision return. Occasionally, high blood pressure will return to normal if the underlying disease is successfully treated. In these cases, the use of antihypertensive medications may no longer be needed.

Cats are not the only pets to experience high blood pressure. Dr. Diane Levitan, DACVIM and director of The Center of Specialized Veterinary Care in Westbury, N.Y., told the story of Sadie, a four-year-old terrier diagnosed with hypertension. Sadie had sustained kidney damage caused by a kidney infection. The infection was treated with antibiotics; however, the kidneys began to lose function resulting in protein loss in the urine and high blood pressure.

Sadie is now nine. By managing her diet, blood pressure and infection recurrence, she has survived several years beyond all expectations with a great quality of life. "Early detection of hypertension in pets with kidney disease is very important," says Levitan. "Studies show that dogs with kidney failure and hypertension can have up to four times higher risk of crisis.

The prognosis is good for treating hypertension if caught early. Pets that have experienced a loss of vision may even have their vision return.

Occasionally, blood pressure will also return to normal if the underlying disease is successfully treated by the pet's family and veterinarian.

For more information on blood-pressure measurement and your pet's risk for hypertension, consult your family veterinarian and www.acvim.org.