High blood pressure (hypertension) is a pathological increase in blood pressure.
A distinction can be made between whether only the systolic blood pressure, the diastolic blood pressure, or both, i.e. the systolic and diastolic blood pressure, are elevated.
Depending on the blood pressure measured, hypertension is classified as mild, moderate, or severe.
High blood pressure can be primary (rare, no other underlying disease is present), secondary (common, other disease or the administration of blood pressure-increasing drugs are the underlying cause) or as the so-called “white coat effect”. Excitement and/or fear during the blood pressure measurement leads to an artificially induced rise in blood pressure.
There are a number of different diseases that can cause secondary hypertension in cats. In addition to acute and chronic kidney diseases, endocrine causes such as e.g. E.g. hyperthyroidism (an overactive thyroid gland) or diabetes mellitus (also known colloquially as diabetes) are known as possible triggers of high blood pressure. Likewise, the presence of pheochromocytoma (a hormone-producing tumor of the adrenal medulla) can lead to high blood pressure.
Diseases that are associated with an increased heart rate, as well as vascular changes (e.g. stenosis (narrowing) of the renal artery), can trigger high blood pressure.
Glucocorticoids and mineralocorticoids are among the drugs that can increase blood pressure.
Since there is an increased risk of end-organ damage as a result of high blood pressure, the detection and treatment of high blood pressure is of essential importance.
Depending on the blood pressure measured, risk categories can be formed, which can be used to assess the potential risk of end-organ damage.
In addition to the kidneys in cats, organs that are at risk of end-organ damage due to high blood pressure also include the eyes, the heart, and the brain/CNS (central nervous system).
Especially in cats, but also in dogs, the eye plays an important role as an end organ damaged by high blood pressure. In addition to bleeding into the eye, the detachment of the retina, which if left untreated, leads to the patient’s blindness, should be mentioned in particular.
The treatment of high blood pressure depends on its root cause (primary, secondary or white coat effect). In the treatment of secondary hypertension, it is important that the underlying disease causing the hypertension is treated.