Heart Disease in Cats: Welfare Management and Care

Feline Heart Disease: A Welfare-Centred Guide

Heart disease is a significant cause of morbidity and mortality in cats, with hypertrophic cardiomyopathy (HCM) being by far the most common form — affecting an estimated 15% of the general cat population and much higher rates in predisposed breeds. Unlike dogs, cats rarely cough with heart disease and often mask signs until the condition is advanced. Understanding feline cardiac disease enables owners to detect problems earlier and manage affected cats effectively, maximising quality of life.

Types of Feline Heart Disease

Hypertrophic Cardiomyopathy (HCM)

The most common cardiac condition in cats — characterised by thickening (hypertrophy) of the left ventricular wall and septum, reducing chamber volume and cardiac output. Can lead to:

Congestive heart failure (pulmonary oedema or pleural effusion)
Arterial thromboembolism (ATE — blood clots causing sudden paralysis)
Sudden cardiac death

Breeds at high risk: Maine Coon (MYBPC3 mutation), Ragdoll (separate mutation), British Shorthair, Bengal, Persian, Sphynx.

Dilated Cardiomyopathy (DCM)

Less common in cats since taurine-deficient commercial diets were corrected in the 1990s. Now rare; may be associated with taurine deficiency (check diet) or idiopathic.

Restrictive Cardiomyopathy (RCM)

Fibrosis of the endocardium restricting ventricular filling. Less common; poorer prognosis than HCM.

Clinical Signs and Detection

Many cats with HCM have no clinical signs initially — the disease may be detected by murmur or arrhythmia on routine auscultation before signs develop.

When signs develop:

Respiratory signs: Open-mouth breathing, increased respiratory rate (>40 breaths/minute at rest), crouching with elbows splayed (signs of respiratory distress)
Exercise intolerance: Reduced activity, preference for resting
Reduced appetite
Weight loss
Sudden paralysis (ATE): Typically affects hindlimbs — sudden onset, cold limbs, vocalisation from pain. A veterinary emergency

The respiratory rate at rest is the most useful owner-monitored welfare indicator. Teach owners to count respiratory rate monthly — a sudden increase is the most reliable early warning of decompensation.

Welfare Impact

Advanced heart disease causes significant welfare compromise:

Respiratory distress from pulmonary oedema or pleural effusion — highly distressing
Arterial thromboembolism causes severe pain from ischaemia in affected limbs
Chronic fatigue and reduced quality of life in progressive disease
Anxiety associated with breathlessness

Management and Treatment

Stage B (Structural disease, no clinical signs)

Monitoring: Echocardiography every 12–18 months
Home monitoring: Monthly resting respiratory rate
Clopidogrel: Antiplatelet therapy recommended for cats at high ATE risk (severely enlarged left atrium)

Stage C (Current or prior signs of heart failure)

Furosemide: Diuretic to manage pulmonary oedema and pleural effusion
Pleurocentesis: Drainage of pleural effusion for immediate relief of respiratory distress
Atenolol or diltiazem: Heart rate control
Clopidogrel: Antiplatelet therapy
Low sodium diet: Reduces fluid retention

Arterial Thromboembolism (ATE)

ATE is one of the most distressing emergencies in feline medicine — sudden painful paralysis causing extreme distress. Immediate veterinary treatment is essential. Key welfare considerations:

Strong analgesia immediately (opioids are essential — ATE is very painful)
Prognosis for recovery is guarded (50–60% may regain some function)
Euthanasia should be discussed honestly if pain cannot be managed
Survivors need antiplatelet therapy lifelong

Quality of Life Monitoring

Daily resting respiratory rate (alarm threshold: >30–35 breaths/min)
Appetite and interest in food
Social interaction and engagement
Mobility and ability to reach key locations (litter, food, water)