Systemic Hypertension in Cats
Hypertension, more commonly referred to as high blood pressure, occurs when the cat's arterial blood pressure is continually higher than normal. When it is caused by another disease, it is called secondary hypertension; primary hypertension, meanwhile, refers to when it actually is the disease. Hypertension may affect many of the cat's body systems, including heart, kidneys, eyes, and the nervous system.
Systemic hypertension can affect both dogs and cats. If you would like to learn more about how this condition affects dogs, please visit this page in the PetMD health library.
Symptoms and Types
The following are just some of the more common symptoms displayed by cats with high blood pressure:
- 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)
The cause of primary hypertension in cats is not known. However, it may have a genetic component. So how prevalent is this form of hypertension? Studies have varied, but one study found that 65 percent of cats with chronic renal failure and 87 percent of cats with hyperthyroidism had mild high blood pressure. Ages of cats with hypertension ranged 4 to 20 years old.
Secondary hypertension, which accounts for 80 percent of all hypertension cases, may be due to a variety of factors, including renal disease, hormonal fluctuation, and hyperthyroidism.
Diabetes may also be a cause for hypertension, although it is uncommon in cats. If you suspect that your cat is suffering from hypertension, bring it in so that your veterinarian may provide a proper diagnosis.
Blood pressure is often measured in pets in the same manner as in humans. An inflatable cuff will be placed on the cat's paw or tail, and standard blood pressure measuring instruments will check the pressure. It is important to keep the cat still long enough to get an accurate reading.
The standards for cat 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 rotuinely 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
Five to seven measurements are generally taken. The first measurement will be discarded, and the cat's excitement level during the procedure will be taken in account. If the results are in dispute, the procedure will need to be repeated.
The underlying cause of the high blood pressure will be treated first. Otherwise, the cat will probably be on medication to control the blood pressure indefinitely. The medication of choice is either a calcium channel blocker or a beta-blocker. As to cat's diet, the veterinarian may recommend food that are lower in sodium.
Blood pressure should be checked regularly, and some lab tests may be ordered by your veterinarian to measure your cat’s reactions to the medication.