Primary hyperaldosteronism (Conn's syndrome) in cats causes hypertension, hypokalaemia, and muscle weakness, and is increasingly recognised as a significant but often missed welfare condition.
Cats with hyperaldosteronism suffer from severe muscle weakness that may prevent normal movement, posture, and self-care. The cervical ventroflexion — inability to hold up the head — is a particularly distressing presentation. Hypertension-induced blindness represents a sudden, permanent welfare loss that is preventable with timely diagnosis and treatment. The condition is often missed because weakness in older cats is attributed to other common conditions — CKD, hyperthyroidism — without investigating the full differential. Measuring serum potassium in any weak or hypertensive older cat is a simple screening step that can prevent unnecessary suffering through delayed diagnosis. The good reversibility of many cases makes early diagnosis especially important.