Home › Animalia › Animal health › Animal diseases › Heart failure in cats
Heart failure in cats
We speak of heart failure when the heart is no longer able to circulate blood properly. Blood stagnates upstream and fluid accumulates in or around the lungs. In cats, it is not a disease in itself but the outcome of a heart disease, most o...
What is it?
We speak of heart failure when the heart is no longer able to circulate blood properly. Blood stagnates upstream and fluid accumulates in or around the lungs.
In cats, it is not a disease in itself but the outcome of a heart disease, most often a cardiomyopathy that has remained silent.
The first sign is almost always respiratory: the cat breathes quickly, then with difficulty. Difficulty breathing in a cat is an emergency, regardless of the cause.
Key point
Rapid or labored breathing in a resting cat is always an emergency. The cat hides its discomfort until the last moment: when it becomes visible, the situation is already critical.
Commonly observed signs
These signs are neither exhaustive nor specific. Only a veterinarian can establish a diagnosis.
Related signs — each one links to its page:
Rapid breathing at rest or during sleep, even before discomfort is visible.
Marked respiratory effort: pumping stomach, exaggerated movement of the sides, tense neck, elbows apart.
Open mouth breathing or panting: this is very abnormal in a resting cat and requires immediate consultation.
Pale, grayish or bluish gums.
Despondency, refusal to move, sitting position in a sphinx because the cat can no longer stand lying on its side.
Loss of appetite and progressive weight loss in forms that have been developing for a long time.
Swelling stomach when fluid accumulates in the abdomen.
Unlike dogs, cats rarely cough: don't count on coughing to identify a heart problem.
When to consult without delay
This list does not replace veterinary advice. It gathers situations that justify a prompt consultation.
Causes and risk factors
Hypertrophic cardiomyopathy is the most common cause: the thickened heart fills poorly and the blood flows back to the lungs.
Other diseases of the heart muscle, dilated or restrictive, lead to the same result.
A heart defect present at birth can decompensate in young cats.
Uncontrolled hyperthyroidism or high blood pressure exhausts the heart over time.
Severe anemia or too rapid perfusion in a cat with a fragile heart can trigger the decompensation of a previously silent disease.
Known heart disease, or a murmur heard during a previous visit.
Breeds predisposed to cardiomyopathy: Maine Coon, Ragdoll, Persian, British Shorthair, Sphynx, Bengal.
Advanced age, due to associated diseases — thyroid, kidneys, blood pressure.
Anesthesia, an infusion, significant stress or an acute illness, which can suddenly reveal latent heart failure.
Diagnosis and care
Diagnosis is the veterinarian's responsibility, based on clinical examination and laboratory tests. Care is decided case by case.
A cat that is breathing poorly should not be examined at length: it is first placed under oxygen, in a quiet area, and handled as little as possible. Stress alone can make the situation worse.
The veterinarian listens for murmurs, galloping or muffled breathing sounds, and measures blood pressure once the cat has stabilized.
A quick ultrasound makes it possible to identify fluid around the lungs and assess the condition of the heart without laying the animal down.
Chest x-rays are taken when the cat is supporting them.
A blood test evaluates the kidneys, thyroid and general balance; a cardiac blood marker helps distinguish a cardiac cause from a pulmonary cause.
If fluid compresses the lungs, it is removed with a needle: relief is often immediate.
Treatment
Treatment for the attack combines oxygen, absolute rest and diuretics to eliminate accumulated fluid.
Removing fluid from around the lungs provides rapid relief when it is abundant.
Once the crisis has passed, basic treatment is put in place depending on the heart disease in question: medications that help the heart to fill or contract, that slow down the rhythm, or that lower blood pressure.
A fluidizing treatment is added when the risk of a clot is high.
The treatment is then adjusted based on regular checks: weight, respiratory rate at rest, kidney tests.
This renal monitoring is not optional: diuretics dehydrate and stress the kidneys, the balance between heart and kidneys must be monitored over time.
Never stop or change cardiac treatment on your own, even if the cat appears cured: the signs disappear because of the treatment, not in spite of it.
Treatment depends on the cause and the animal's condition: it must be determined by a veterinarian. No self-medication.
Prevention
Detecting heart disease before decompensation is the only real way to act: annual auscultation, ultrasound in breeds at risk and before anesthesia.
Treating hyperthyroidism or high blood pressure early protects the heart.
At home, counting the sleeping cat's respiratory rate once a week helps identify decompensation that is beginning, often several days before visible discomfort.
A cat with heart disease should be transported and handled calmly; stress is a recognized triggering factor.
Possible complications
Acute respiratory distress, which can be fatal within hours.
Migration of a clot towards the hindquarters, with sudden and very painful paralysis.
Heart rhythm disturbances and risk of sudden death.
Kidney damage, aggravated by diuretics necessary for the heart: the balance between the two organs is sometimes difficult to maintain.
Weight loss and muscle wasting in chronic forms.
Recurrences of decompensation, particularly if treatment is discontinued.
When to see a veterinarian
Your cat is breathing quickly, hard or with difficulty when resting: emergency, even if he does not seem to be in pain.
He is breathing with his mouth open, panting, or his gums are pale or blue: absolute emergency.
He remains seated with his neck outstretched and refuses to lie down.
His stomach swells and he becomes thinner.
He no longer uses his back legs: absolute emergency.
His respiratory rate measured during sleep increases significantly from one week to the next: call without waiting for the signs to appear.
Prognosis
Heart failure marks a turning point: the heart disease is now advanced and treatment becomes permanent.
Many cats nevertheless return to a comfortable, calm and good quality life for a period of time which varies greatly depending on the disease in question and the response to treatment.
The prognosis is better when a correctable cause is found — thyroid, blood pressure — and treated.
The regularity of processing and controls is the factor over which the owner has the most control.
Frequently asked questions
How do I count my cat's respiratory rate?
While he's sleeping soundly, count the movements of his ribcage — one inhale and one exhale counts as one — for one minute. Note the figure each week: it is the evolution that counts, more than the isolated value.
My cat is doing much better: can I stop the medication?
No. Improvement is the result of treatment, not evidence of a cure. Stopping most often leads to a rapid, sometimes serious, relapse. Any modification must be decided with the veterinarian.
Is my cat with heart disease coughing like a dog with heart disease?
Very rarely. In cats, the warning sign is rapid or difficult breathing. A cough in a cat suggests asthma or another respiratory disease, and also merits a consultation.
Is a special diet required?
A moderately low salt food may be advisable, but the top priority is for the cat to eat. A cat with heart disease who refuses his bowl weakens quickly: it is better to have a food that he accepts, chosen with the veterinarian.
References
AAFP — American Association of Feline Practitioners
Content reviewed by the TunisieVet editorial team · Updated 09 August 2026
AT A GLANCE
Need a veterinarian?
Find a practitioner near you on TunisieVet, with their specialities, hours and contact details.
Find a veterinarianCategories
Affected species
This information is provided for educational purposes only and is not a substitute for a veterinary consultation. If you have any concerns about your animal's health, consult a veterinarian.
To discover
Related diseases and linked Animalia content.
Rabies
Viral · Vaccine available
Hip dysplasia
Other
Otitis externa
Environmental
Periodontal disease
Other