The term hypertension may bring to mind an overweight, red-faced gentleman sitting at a desk rubbing his chest. But, did you know that your senior pet can also be affected by hypertension? While the precipitating factors that cause hypertension in pets are different from those in humans, the disease can still be problematic for your senior pet.

What is hypertension in senior pets?

The cardiovascular system's main role is to maintain the appropriate intravascular pressure to adequately perfuse the body’s tissues. Blood pressure measures the pressure in systemic arteries. If the blood pressure falls below the normal range, the condition is called hypotension, which leads to inadequate organ perfusion. If the blood pressure rises above the normal range, the condition is called hypertension, which leads to damaging over perfusion of the organs.

Systolic pressure is the pressure inside the systemic arteries when the heart contracts and diastolic pressure is the pressure inside the systemic arteries when the heart relaxes. When measuring a senior pet’s blood pressure, their circumstances and condition should be considered, but normal blood pressure for a pet is generally about 120 mmHg systolic and 80 mmHg diastolic. Three types of hypertension can affect senior pets:

Situational hypertension — In human medicine, this is known as “white coat syndrome.” Excitement or anxiety can increase blood pressure in a senior pet who is otherwise normotensive, which can make getting an accurate reading difficult. Multiple measurements should be taken, and measuring your senior pet’s blood pressure at home may help distinguish between situational hypertension and more concerning types.

Idiopathic hypertension — Also referred to as primary hypertension, this occurs when your senior pet’s blood pressure is elevated without an identifiable underlying cause. This diagnosis is made when reliable blood pressure measurements suggest hypertension, but the pet’s complete blood count, serum biochemistry, and urinalysis results are normal. Subclinical issues could potentially cause increased blood pressure, and further diagnostics should be performed to rule out these issues.

Secondary hypertension — This diagnosis is made when your senior pet has hypertension and a concurrent disease or condition known to cause hypertension. Certain therapeutic agents and toxins can also cause an increase in blood pressure. Pets are most commonly affected by secondary hypertension.

What causes secondary hypertension in senior pets?

Numerous conditions can cause your senior pet to develop secondary hypertension, which may persist after the primary issue has been addressed. High salt diets do not seem to affect a pet's blood pressure as they do in people.

In dogs, causes include:

• Acute and chronic kidney disease
• Hyperadrenocorticism (i.e., Cushing’s disease)
• Diabetes mellitus
• Obesity
• Pheochromocytoma (i.e., adrenal tumor)

In cats, causes include:

• Chronic kidney disease
• Hyperthyroidism
• Hyperadrenocorticism

Medications that can cause secondary hypertension include:

• Glucocorticoids
• Ephedrine
• Pseudoephedrine
• Phenylpropanolamine
• Phenylephrine hydrochloride

What are hypertension signs in senior pets?

If your senior pet’s hypertension is caused by an underlying disease, they will exhibit signs related to that condition. Sustained high blood pressure can result in tissue damage, referred to as end-organ damage. Multiple organs can be affected.

Kidneys — Exacerbates chronic kidney disease, causing decreased appetite, weight loss, excessive water intake and urination, vomiting, and diarrhea

Eyes — Causes retinal edema and hemorrhage, leading to retinal detachment, which results in acute onset blindness

Brain — Damages brain tissue, resulting in seizures, incoordination, and sudden collapse

Heart — Causes thickening of the left lower heart chamber, resulting in difficulty breathing as blood backs up in the lungs because the heart can no longer pump effectively

Blood vessels — Causes vessels to narrow, rupture, or leak, resulting in blood in the urine, nosebleeds, and stroke

How is blood pressure measured in senior pets?

The technique for measuring your senior pet’s blood pressure is similar to your own blood pressure being evaluated. A small cuff is placed on their front limb, and an ultrasound probe is used to hear the blood flow return. A stethoscope is not sensitive enough to detect the blood flow in your senior pet’s small vessels.

How is hypertension treated in senior pets?

Because hypertension in your senior pet usually results from an underlying condition, that issue needs addressing to help decrease their blood pressure. Antihypertensive medications can be used to help gradually decrease your pet’s blood pressure as sudden, drastic drops can be dangerous. Your pet will need life-long monitoring and management to ensure their hypertension is controlled.

If your pet’s quality of life is adversely affected by hypertension or another disease process, contact our telehospice service to determine if they would benefit from services offered by a Lap of Love veterinarian in your area, such as veterinary hospice care or in-home euthanasia.