High blood pressure, medically referred to as systemic hypertension, occurs when a dog's arterial blood pressure is constantly higher than normal. If it is caused by another disease it is called secondary hypertension. If there is no other disease involved it is referred to as primary hypertension. This disease affects many of the dog's systems, including the nervous system, heart, eyes, and kidneys.
This disease is not only found in dogs but also in cats and other animals.
Symptoms and Types of Systemic Hypertension
There is basically only one type of high blood pressure but it has many different symptoms. Some of which are here:
- Dilated pupils
- Retinal detachment
- Hemorrhage of the eye
- Blood in the urine
- Protein in the urine
- Bleeding from the nose
- Swollen or shrunken kidneys
- Heart murmurs
- Weakness, either on one side of the body or in the legs
- Involuntary oscillation (rolling) of the eyeballs
- Palpable thyroid gland (when hyperthyroid)
Causes of High Blood Pressure in Dogs
The actual cause of primary hypertension in dogs is currently unknown. However, there may be a genetic component to this disease because dogs with high blood pressure produce offspring with hypertension.
It also seems that this disease is increasing in numbers in the dog population. A study found that there are between 0.5 percent and 10 percent of dogs suffering from this disease. And the disease is found in dogs between the ages of 2 and 14 years old.
Secondary hypertension accounts for 80 percent of all high blood pressure cases. This form of hypertension may be due to a variety of factors, including hyperthyroidism, hormonal fluctuations, and renal disease.
Diabetes can also cause high blood pressure in dogs but it not a common cause.
Diagnosing High Blood Pressure in Dogs
To determine the blood pressure of a dog an inflatable cuff is placed on the dog's paw or tail. The cuff is then inflated and a measurement is taken. It is important that the dog remain still for the veterinarian to get an accurate measurement.
The standards for dog blood pressure are:
- 150/95 – at this reading or below, there is minimal risk and treatment is not recommended
- 150/99 to 159/95 -- intervention is routinely not recommended at these readings
- 160/119 to 179/100 -- treatment should be sought to limit the risk of organ damage
- 180/120 -- immediate treatment should be sought to limit the degree of other more severe complications
In determining the blood pressure of the dog, the veterinarian will take several measurements. The first measurement is always discarded as this measurement is mostly used to determine the level of the dog's excitement during the examination. There may be as many as 7 measurements taken to get a good indication of the dog's blood pressure.
Treating Systemic Hypertension
The first thing to be treated is the underlying cause of the high blood pressure. If the underlying cause cannot be determined the dog may have to be on medication for life.
There are two types of medication that is used to control high blood pressure in dogs. The veterinarian will prescribe either a calcium channel blocker or a beta-blocker.
Diet is another factor that will have to be controlled. A low sodium diet is often recommended in addition to medication.
Regular blood pressure exams will also be required to help control the disease. And the dog will also have to undergo certain lab tests to measure the dog's reactions to the medication.