Hypertension, or high blood pressure, is a condition that affects many people. Did you know that dogs can have hypertension as well? The potential causes of high blood pressure in dogs are somewhat different than for humans, but hypertension is still a concern in dogs.
What is Hypertension in Dogs?
Systemic hypertension in dogs is high blood pressure. Blood pressure is the measurement of the pressure of the blood flow against the walls of the arteries as the heart pumps blood. Systolic blood pressure specifically refers to the pressure against the arteries as the heart contracts while diastolic describes the pressure when the heart relaxes.
Blood pressure is measured in millimeters of mercury, abbreviated as mmHg. Blood pressure results are read as systolic over diastolic. For example, if the systolic is 140 and diastolic is 80, the reading would be 140/80 mmHg.
Signs of Hypertension in Dogs
Hypertension itself does not usually cause specific signs in dogs. However, the harmful effects of high blood pressure can cause bleeding in parts of the body, lead to blood clot formation, and relate to problems like kidney disease. The following signs might be seen in conjunction with hypertension in dogs:
- Sudden blindness (due to retinal detachment)
- Bleeding in the eye
- Blood in the urine
- Nosebleed (epistaxis)
- Heart disease signs (difficulty breathing, possible coughing, lethargy)
- Blood clot formation that can lead to stroke (less common in dogs than in humans)
- Loss of appetite
- Increased thirst and urination (due to kidney disease)
How is Blood Pressure Measured in Dogs?
In dogs, blood pressure is often measured using a special cuff attached to an oscillometric blood pressure monitoring device. In some clinical settings, the cuff is attached to a sphygmomanometer (handheld pump to inflate the cuff with a dial to measure pressure) and a Doppler pulse monitor that is attached to a pulse site. Areas commonly used to measure blood pressure in dogs include the front limbs, the tail, and the lower rear limbs (below the hock).
It can be difficult to obtain an accurate blood pressure measurement on a dog in a clinical setting. First, nervousness or excitement can artificially raise blood pressure. Second, dogs are not as likely to sit still for the measurement. Veterinary professionals work to keep dogs relaxed and calm so they can properly measure blood pressure. Steps are taken to ensure that the right cuff size is used and the equipment is operated properly. Several measurements are needed to confirm the results.
When interpreting blood pressure readings, veterinarians take into account factors that can affect BP, such as age, sex, breed, and current attitude. So-called "normal" BP can fall within a wide range, usually between 131/71 and 150/95 mmHg. BP over 150/95 may be harmful to the body. The elevated BP, along with evidence of targeted organ damage, warrants some form of medical treatment. A BP greater than 180/120 is considered serious. These dogs will need medical intervention to prevent secondary problems, such as: chronic kidney disease, retinal pathology (leading to blindness), vascular lesions (causing stroke), and heart disease (such as congestive heart failure).
Causes of Hypertension in Dogs
Most dogs with high blood pressure have secondary hypertension, meaning the blood pressure is elevated due to another problem in the body. Secondary hypertension may be caused by one or more of the following conditions:
- Kidney disease
- Endocrine problems like diabetes mellitus
- Adrenal gland problems like Cushing's disease or adrenal tumors
Primary hypertension is less common in dogs. It is not known what causes these dogs to have high blood pressure, but age may be a contributing factor.
Treatment of Hypertension in Dogs
Once your veterinarian has diagnosed hypertension in your dog, the next step is to look for an underlying cause. Managing the primary disease can help reduce blood pressure. However, most dogs will still need medication to lower blood pressure.
Veterinarians often prescribe vasodilators, a group of drugs that open the blood vessels and reduce blood pressure. Common medications used for hypertension include the following:
Lowering dietary sodium intake is sometimes recommended in dogs, but this is not as prevalent as it is in humans. Your vet can recommend special foods for your dog if a low-sodium diet is recommended.
Be sure to follow your vet's treatment plan precisely and go back for follow-up visits as recommended. Contact your vet if your dog is not responding well to treatment or if there are changes in your dog's condition. Never adjust medications or other treatments without talking to your vet first.
How to Prevent Hypertension in Dogs
You may not be able to prevent high blood pressure in your dog, but you can help keep it under control. Early detection is one of the best ways to keep your dog healthy.
Make sure to visit the vet once or twice a year as recommended for wellness check-ups (more often as your dog ages). Your vet may be able to detect small changes that indicate a problem. If you are concerned about your dog's blood pressure, ask if that can be checked at the next visit.
It's also important to bring your dog for a veterinary exam as soon as you notice signs of illness. Waiting will only make your dog's condition more difficult to manage.