Canberra Cat Vet Blog

High Blood Pressure can cause blindness in cats; have you had your senior cat’s blood pressure taken lately? Systemic hypertension – a persistent increase in blood pressure – is commonly recognized in feline practice.

Feline hypertension is commonly found as a complication of other underlying medical conditions (secondary hypertension), although primary hypertension (hypertension without any underlying disease) may also be seen in cats. In contrast to people, where primary hypertension (also called essential hypertension) is most common, secondary hypertension is more common in cats. Primary hypertension accounts of less than 20% of feline cases.

The most common secondary causes of hypertension are chronic kidney disease (CKD) and hyperthyroidism. Other causes include hyperaldosteronism (Conn’s syndrome), chronic blood loss adrenal tumours and erythropoietin therapy

Unfortunately hypertension is often only suspected very late in the course. The target organs most vulnerable to hypertensive damage are the brain (usually behavioural, night vocalization, signs of dementia), heart, kidneys and eyes (blindness). The goal of managing high blood pressure is to identify and treat underlying causes, and to reduce systemic blood pressure to an ideal range with anti-hypertensive medications.

Blood pressure should be evaluated as a routine part of check-ups for all cats past 7 years of age. We can help measure your feline friend’s blood pressure with a Doppler machine at their next visit for their wellness check.

When we read about recent cases of thiamine deficiency in cats fed preserved pet meats in Sydney we also found this American report about thiamine deficiency in cats fed uncooked fish and some pate type can foods.

Thiamine is essential for carbohydrate metabolism, muscle contraction, and nerve conduction. Very little thiamine is stored in the body and cats depend on a steady dietary source of the vitamin. Thiamine is naturally found in many food sources such as whole grain cereals, nuts, legumes, brewer’s yeast, but cats derive thiamine mainly from meat products, in particular skeletal muscle, liver, heart, and kidneys.

Improper food storage and processing, consumption of uncooked fish that contain the enzyme thiaminase, and consumption of diets with sulfur dioxide or sulfite meat preservatives can lead to insufficient dietary thiamine.

After two to four weeks of a thiamine deficient diet, cats exhibit salivation, anorexia (loss of appetite), and sometimes vomiting. If the deficiency is not corrected, then dilated pupils, bradycardia (slow heart rate), aggression, and progressive neurological symptoms such as ataxia (loss of coordination), rigid head and neck ventroflexion, twitching, loss of righting reflexes, seizures, coma, and death will ensue. Rigid head and neck ventroflexion is the most common clinical sign in cats presented to veterinarians.