Hypertension or high blood pressure in felines can occur at any age, but is most common in senior cats. Typically, hypertension is caused by an underlying condition such as kidney failure or thyroid problems. Consequently, the hypertension symptoms will be characteristic for the underlying medical conditions. If the hypertension is primary, having no underlying causes, the symptoms will include weakness, vision problems or collapse.
Causes of Hypertension
The causes of hypertension are important as the clinical signs the cat displays will depend on these.
The main causes of hypertension in cats include:
- Kidney failure
- Thyroid problems
Primary hypertension is rare in cats, but may occur; the cause of primary hypertension is not clear; it may be an inherited condition.
Symptoms of Hypertension
The symptoms displayed by a cat with high blood pressure will depend on the underlying cause.
If the cat has a kidney problem that causes hypertension, the symptoms will include:
- Lethargy
- Lack of appetite
- Weight loss
- Increased thirst
- Increased urination
- Vomiting
When the high blood pressure is caused by hyperthyroidism, the clinical signs may include:
- Weight loss
- Vomiting
- Oily skin and chin acne
- Increased thirst and urination
- Increased irritability
- Restlessness
If the cat has primary hypertension, he may have no symptoms or display a number of clinical signs such as:
- Eye problems such as retinal detachment and even blindness
- Seizures, if there are blood vessel injuries in the central nervous system
- Sudden collapse
- Changes in behavior
- Irritability and restlessness
- Arterial spasms
The hypertension can create kidney and heart problems if left untreated.
Diagnosing Hypertension
Feline blood pressure can be measured and if the values are above normal (i.e. 180 to 200 mm Hg for systolic readings and 100 to 110 mm Hg for diastolic readings) this means that the cat has high blood pressure.
The vet may also perform additional tests to determine if there are any kidney or thyroid problems causing the elevated blood pressure.
Treatment for Feline Hypertension
The severity and the underlying cause of hypertension will influence the treatment. If the hypertension is mild and is a primary condition, the vet may not prescribe any medication.
If the hypertension is more severe, the treatment will contain diuretics and beta blockers. The diuretics will decrease the volume of the blood and water and salts in the body.
The beta blockers will decrease the heart rate and consequently lower the blood pressure. Alpha blockers may also be recommended; these decrease the blood vessel resistance. Angiotensin converting enzyme (ACE) inhibitors may also decrease blood pressure.
The vet may also prescribe medication for the underlying cause of the elevated high blood pressure.
The cat should be monitored to see if the symptoms persist. The blood pressure will be measured periodically and the medication dosage will be altered according to the general state of the cat. It is also important not to allow the blood pressure to drop, causing hypotension.