Causes and Treatment of Canine High Blood Pressure

"Canine high blood pressure, is also referred to as “hypertension”. There are two main types; systemic and pulmonary. Systemic hypertension is represented by high blood pressure in almost all blood vessels of the body; while pulmonary hypertension is specific to the pulmonary (lung) arteries only. Systemic and pulmonary hypertension may be primary or secondary (caused by another condition). In most cases, primary or idiopathic (having no known cause) types of canine high blood pressure are less common in dogs. The secondary form of systemic hypertension is mainly due to any underlying disease. Renal Disease (kidney), Diabetes Mellitus, and Hyperadrenocorticism etc. are the most common causes of secondary canine high blood pressure. Pulmonary hypertension on other hand is specifically a defect in pulmonary blood flow; which may  either be due to the viscosity of the blood or due to a ventricular defect in the heart; which supplies blood to the pulmonary system. Diagnosis of canine high blood pressure  is done by the clinical measurement of the blood pressure; while in some cases advanced techniques of echocardiography may be required. No definite treatment is available and diagnosed dogs may require long-term management through prescription medications and by making sure a dog is getting the proper nutrition. "

Types of Canine High Blood Pressure:

There are mainly two forms of high blood pressure in dogs, systemic and pulmonary. Systemic hypertension or high blood pressure is more common in dogs; while pulmonary hypertension is noted only in some hunting dogs.

Systemic Hypertension:

Systemic hypertension may be primary or secondary. Primary or essential hypertension is rare in dogs, and is more common in humans, as it is related to psychological stress.  Secondary hypertension on the other hand is the most common form of canine high blood pressure; which is caused by some underlying pathological condition or disease. 

Dogs may suffer from a number of diseases; which can result in high blood pressure; Renal Diseases (kidney disease) are the most common group of pathological conditions; which can cause canine high blood pressure. Renal diseases can cause high blood pressure, irrelevant of age, breed or sex. This  means that any dog suffering from any renal disease, either has calculi (kidney stones), infection or any congenital (inherited) problem, it is at high risk of high blood pressure.

Some other diseases like Diabetes Mellitus, Hyperadrinocorticism and pheochromocytoma (type of adrenal gland tumor) , can also leave a dog with high blood pressure.

Canine Pulmonary Hypertension:

This is an uncommon form of dog high blood pressure which is seen in hunting dogs and rarely in other breeds. It is specifically related to the pulmonary blood supply, caused mostly by the narrowing of the ventricle in the heart. This condition increases blood pressure as it is supplied to the pulmonary vessels.

Some diseases, such as canine heartworm disease, stenosis (narrowing of openings in the heart), and arterial septal defects are common reasons for pulmonary hypertension in dogs.

Signs:

Even in severe high blood pressure cases, no clinical signs reported are associated with hypertension. It may be, because those signs related to high blood pressure are similar to those associated with any underlying disease. Lesions in the eye e.g. retinal hemorrhage and edema may represent the only specific signs of severe  high blood pressure.

Diagnosis:

Clinical measurement of blood pressure is considered the most effective way to diagnose high blood pressure in dogs. The most precise, clinical method is by measuring pressure through an arterial puncture, but it is impractical , thus the most common way to measure it indirectly is with a “Doppler probe”, i.e. to assess blood flow in the artery, through a cuff; which is installed in over a 40% circumference of the dog’s forelimb. The disadvantage of this method is that the systolic pressure is the only measurement possible.

Pulmonary hypertension on the other hand, can be measured directly or through Doppler echocardiography; which can confirm a defect in the ventricle and a vascular defect in the pulmonary bed.

Dog High Blood Pressure Treatment:

Treatment for high blood pressure should only be initiated once it has been confirmed  or when the causative underlying disease is diagnosed.

Treatment of the underlying disease, usually does not resolve, dog high blood pressure; thus it may persist even after recovery. High blood pressure is  specifically  treated, through the long-term use of drugs; such as  enalapril, atenolol or furosemide; which is given orally. Please be advised that dose rates differ in different conditions and age groups dogs.

Pulmonary hypertension on the other hand, once diagnosed; should be considered a “poor prognosis”, resolving underlying conditions can only improve,  but cannot completely resolve it.

There is a homeopathic supportive therapy available that can provide supportive care in terms of supporting a dog's circulatory system and heart.   Heart & Circulation Tonic contains ingredients such as Crataegus (supports pumping ability of the heart), Arnica (supports heart health) and Kali phos (helps to keep dog blood pressure within a normal range).  Be sure to check with your veterinarian so that he or she can track effectiveness and common on the use of this product.

References:

The Merck Veterinary Manual