We didn’t think blood pressure in dogs and cats was a problem until fairly recently.
Now we know that high blood pressure is linked with some serious diseases in dogs and cats, and that we should monitor it.
Blood pressure is the pressure the blood exerts as it flows against the blood vessels.
High blood pressure (called hypertension) is an abnormal elevation in that pressure, which can lead to serious problems in both pets and people, though it’s much more common in people.
Changes in the blood vessels make pushing blood around the body more difficult, increasing resistance to flow, which in turn increases blood pressure.
This is why certain conditions are associated with hypertension, although a fair few cases are “idiopathic,” which means no cause is found.
High Blood Pressure in People vs. Pets
Many people have primary hypertension, which means it’s not linked to any other medical condition.
But animals rarely have primary hypertension.
Instead, they usually have secondary high blood pressure, caused by conditions such as kidney disease, Cushing’s disease, hyperthyroidism and diabetes. We treat the primary disease, and then we address the high blood pressure.
People have much more high blood pressure than pets, often because of lifestyle: When was the last time you saw your Doberman walk through the door with a carton of cigarettes, or order a double cheeseburger and fries?
And how about the stress in your pet’s life as a risk factor? As we run around like mental maniacs juggling jobs, children, spouses and the rest, what are your cats doing? They are considering whether or not to leave the couch to get a snack.
For most well-cared-for pets, they live a fairly stress-free life.
Measuring Blood Pressure in a Dog or Cat
At a recent vet visit, your veterinarian might have suggested measuring the blood pressure of your dog or cat.
Something in your pet’s history suggested that high blood pressure might be a problem, or a blood pressure reading may have been part of a geriatric work-up.
Vets don’t routinely take blood pressure in a dog or cat because:
- Hypertension is not common in pets.
- There is still a large margin of error when measuring blood pressure in dogs and cats. We attribute this to the “white coat” phenomenon (meaning the stress caused by being seen by the doctor) and the difficulty in taking measurements in animals under 15 pounds.
Many of you can relate to the white coat issue: Does your anxiety level rise as soon as you walk into your physician’s office? Mine does.
There are 2 ways to measure a pet’s blood pressure:
Using either of these instruments requires technique and patience on the vet’s part, and calmness and patience on your part.
You may be asked to be in the room for a calming effect on your pet.
However, yelling about how cute the little blood pressure “cuffs” are and petting your cat uncontrollably while cackling about how your blood pressure goes through the roof at the doctor’s office is not conducive to lowering your cat’s blood pressure.
Instead, your soothing presence and low voice is what we need while trying to get several readings.
Before taking the blood pressure reading, your vet will probably try to get your pet into a quiet room quickly, away from the waiting room. The general rule is to let the pet acclimate to the new surroundings and then take a blood pressure in a few minutes.
If the dog or cat seems more relaxed after the exam, your vet may take the blood pressure again and compare them.
The vet may take multiple readings, actually. Some try to take at least 3–4 readings and get an average.
In the video below, David Liss, RVT, demonstrates how to take a dog’s blood pressure:
If the readings are high, and the animal has a condition that can cause hypertension, then:
- Blood pressure medicine should probably be prescribed.
- Lowering the salt content of the food is also a good move at this point.
Once the primary disease is identified and controlled, we may be able to discontinue the blood pressure medicine.
Why? Because if we lower the blood pressure too much or continue to medicate when it isn’t necessary, your pet can become weak and dehydrated from low blood pressure, and that can also be dangerous.
High Blood Pressure in Dogs and Cats: Associated Diseases
- Kidney disease is one of the primary causes of secondary high blood pressure in cats.
- Hypothyroidism is the other major cause.
Around 65% of cats with kidney disease also have hypertension, whereas for cats with overactive thyroid glands the figure is a staggering 87%.
Many senior cats suffer from chronic renal failure and hyperthyroidism, making them prime targets for hypertension. Treating high blood pressure when present in a cat with failing kidneys prolongs and improves quality of life.
A common drug prescribed for these cats is a calcium channel blocker called amlodipine.
If your cat suffers from hyperthyroidism alone, treating the thyroid disease may bring the blood pressure back to normal without additional medication, or the amlodipine may be needed only for a short time.
Dogs can also develop high blood pressure if they are in kidney failure and can be medicated as well.
If your dog has been placed on blood pressure medicine, depending on the severity and concurrent disease, the vet will probably recheck the blood pressure in 1–3 weeks. Some of these medications also require blood checks to ensure that the medication isn’t actually hurting the kidneys. Then, follow your vet’s advice on monitoring.
Cushing’s disease (hyperadrenocorticism) is another major cause of high blood pressure in the dog. Dogs who have Cushing’s disease but are otherwise healthy have an 80% risk of hypertension.
Treating the high blood pressure along with treating the Cushing’s can reduce the risk of stroke-like events that plague Cushing’s dogs. (Cats can get Cushing’s disease, but it is rare and virtually untreatable.)
Diabetes can cause high blood pressure. This is more of a problem in diabetic dogs than diabetic cats. We need to monitor blood pressure in these pets.
Symptoms of High Blood Pressure in a Dog or Cat
The most serious clinical manifestations of untreated hypertension are ocular and neurologic emergencies such as:
- Acute blindness
- Vascular “accidents” that resemble strokes
These can be fatal in some instances.
Sudden blindness, a common and distressing symptom, especially in cats, is caused by fluid building up behind the retina, which forces it to detach. If this is caught early, prompt treatment may save that pet’s sight.
The symptoms of high blood pressure in dogs can be even more dramatic, including “funny turns” or, more seriously, strokes.
Sadly, the first sign can be something as awful as sudden death — hence the need for regular blood pressure screening to catch the problem before a catastrophic event happens.
In these cases, if hypertension is found, lowering the blood pressure quickly is essential if the pet is to regain function or to survive.
In most cases, however, hypertension in a dog or cat is more of a chronic condition that can be managed over a period of months as you work to lower blood pressure and treat the primary disease.
Treatment Will Only Get Better in the Future
We still have a lot to learn about diagnosing and monitoring blood pressure in cats and dogs.
Some animals have been misdiagnosed as having hypertension and are on unnecessary blood pressure medication. This is because of an inaccuracy in measurements and the white coat effect.
Other animals are walking around like ticking time bombs because high blood pressure can have an insidious onset, be asymptomatic and thus go undiagnosed.
As our ability to measure blood pressure more accurately improves, so will the treatment.
Preventing High Blood Pressure in Dogs and Cats
Regular screening of pets, especially those classed as “senior,” can detect blood pressure changes in the early stages before they cause a problem.
Current recommendations are that all dogs with Cushing’s disease should have their blood pressure measured every 3 months, which also goes for cats with kidney disease and/or hyperthyroidism.
If your pet is over the age of 7 years but is otherwise well, then once-yearly screening is fine. Once he reaches his teens, it should be twice a year.
If your animal has been diagnosed with one of the diseases mentioned above, or if you have noticed anything different in the mental behavior or eyesight in your older pet, see your vet to discuss possible causes.
Be patient about the blood pressure measurements. You may have to go back for another visit to confirm readings. Some feline specialists even suggest a home visit if the cat is fractious or extremely stressed in the vet’s office.
And for yourself: Let’s work on lowering your blood pressure.
Stop the smoking! Watch the partying! Lay off the extra salt! Get out and take a stress-free dog walk!
And then go home and pet that great dog of yours. It’s proven to lower blood pressure.
- Burkitt Creedon, Jamie M., DVM, DACVECC. “Indirect Blood Pressure Measurement.” NAVC Clinician’s Brief. May 2012. http://www.petvetbiomed.com/html5/web/10200/24004ImageFile3.pdf.
- Primmer, Kathryn, DVM. “Journal Scan: New Insights on Treating Hypertension in Cats.” DVM360. March 29, 2017. http://veterinarymedicine.dvm360.com/journal-scan-new-insights-treating-hypertension-cats.
- Tilley, Larry P. and Francis W.K. Smith Jr. Blackwell’s Five-Minute Veterinary Consult: Canine and Feline. Wiley Blackwell. 706–07.
- Vormbrock, J.K. and J.M. Grossberg. “Cardiovascular Effects of Human-Pet Dog Interactions.” Journal of Behavioral Medicine. 1988 Oct;11(5):509–17. https://www.ncbi.nlm.nih.gov/pubmed/3236382.
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