Medically known as tachypnea, rapid breathing is a respiratory disorder characterised by abnormal breathing that is rapid and shallow. It is caused by a reduced level of oxygen, mechanical disorders (where the lungs aren't able to expand as they should, usually due to a build-up of fluid in or around the lungs), and physiological disorders in which the cat's respiratory centre in the brain is over stimulated.
Rapid breathing after exercise or exertion is not defined as tachypnea and normally settles down after a short amount of time.
The normal respiration rate for cats is 20-30 breaths per minute, which is approximately twice that of humans. There are several types of breathing disorder which can affect cats, this article will focus on tachypnea only. Differences in the other types of breathing can be subtle, and many definitions can cross over. Other types of breathing disorder include dyspnea,
There are three main causes of rapid breathing in cats, reduced oxygen, mechanical difficulty and physiological.
- Anemia (low red blood cell count). The red blood cells deliver oxygen throughout the body.
- Pneumonia, lung infection of inflammation.
- Metabolic acidosis can be caused by many factors such as sepsis, kidney failure, diabetes and poisoning (antifreeze, aspirin poisoning).
- Heart failure. As the heart becomes more and more inefficient at pumping oxygenated blood to the tissues.
- Hypoxemia (low oxygen blood levels).
- Hypovolemic shock.
- Heartworm infection.
- Heart arrhythmia is a disturbance in the heart's normal rhythm.
- Hypertrophic cardiomyopathy this condition can result in fluid buildup in the pleural cavity or lungs.
- Pleural effusion, build up of fluid in the pleural cavity, the fluid-filled space which lies between the lungs and the chest wall. There are many causes of pleural effusion including congestive heart failure, liver disease, hernia, pulmonary embolism and fluid overload.
- Pulmonary edema is a buildup of fluid within the air sacs in the lungs.
- Pyothorax is a build up of pus in the pleural cavity.
- Airway obstruction.
- Lung hemorrhage.
- Pulmonary thromboembolism A pulmonary thromboembolism (PTE) is a blockage in an artery in the lungs by an embolism, which is a substance which has travelled through the circulatory system from another part of the body
- Certain medications or drugs such as aspirin, cannabis.
Obviously, the main symptom is rapid, shallow breathing, the mouth is usually closed. A number of other symptoms may also be tied in with breathing difficulty. Accompanying symptoms may include:
- Cyanosis (blue tinged mucous membranes).
- Coughing and gagging.
- Exercise intolerance/reluctance to move.
Additional symptoms will depend on the underlying cause.
Any type of breathing difficulty is a medical emergency and should be seen to by a veterinarian urgently.
Your veterinarian will perform a complete physical examination of your cat including listening to the heart and lungs for signs of heart abnormalities or fluid build-up in or around the lungs. He will obtain a medical history from you including the onset of symptoms, any medications your cat has recently had, any underlying medical conditions. He will need to perform some diagnostic tests including:
- Complete blood count, biochemical profile, and urinalysis to look for signs of anemia, infection or organ dysfunction.
- X-Rays or ultrasound may be performed to evaluate the heart, liver, and lungs for signs of enlargement, fluid, tumours, hernia or obstruction.
- Echocardiogram of the heart to evaluate the size and function as well as look for heartworms.
- Blood test to check oxygen and carbon dioxide levels in the blood.
- Thoracentesis is a procedure to remove fluid from the pleural space. It serves two purposes, it relieves compression making it easier for your cat to breathe and it provides your veterinarian with fluid samples which can be analysed to determine the cause.
- Antibody or antigen tests for heartworm infection.
- Specific blood tests to check levels of thyroid hormone in the blood if hyperthyroidism is suspected.
Treatment varies depending on the underlying cause. If your cat is experiencing difficulty breathing he may require oxygen therapy and be stabilised before treatment can begin. Your cat will need to be hospitalised if this is the case. Some ways the above conditions are treated include:
- Surgery to remove obstructions, tumours and to repair a hernia.
- Heartworm medications to treat severe heartworm infection, this must be given under close observation from your veterinarian as a dead heartworm has the potential to cause pulmonary embolism.
- Determining the cause and treating for anemia. Severely anemic cats may require a blood transfusion. Your veterinarian may also give your cat erythropoietin, which is a hormone produced by the kidneys which instruct the bone marrow to produce more red blood cells.
- Antibiotics will be prescribed to treat bacterial pneumonia.
- Hyperthyroidism is treated either by surgical removal of the thyroid gland, which will require lifetime medications to replace the thyroid hormones or radioactive iodine treatment which destroys the tumour while leaving the thyroid gland intact.
- Asthma is managed with bronchodilators to help open the airways as well as oral or inhalant glucocorticoids.
- Hypoglycemia is treated with administration of glucose, and possibly glucocorticoids to stabilise his blood sugar levels. If your cat is a diabetic, it may be necessary for your veterinarian to re-evaluate his insulin requirements.
- Arrhythmias are treated by finding and addressing the underlying cause. Your cat may require medications to control the arrhythmias also. In some cases, your veterinarian may recommend a pacemaker for your cat.
- Heart failure can't be reversed but addressing the underlying condition as well as managing symptoms can relieve symptoms. This may include diuretics to help remove fluid by increasing urine output, ACE inhibitor medications to relax blood vessels and lower blood pressure and vasodilators to open up blood vessels which help prevent fluid build-up.
- Pulmonary edema is treated by giving diuretics to help remove excess fluid, pain killers to relieve discomfort as well as treating the cause of fluid build up.
- Pleural effusion and pyothorax are treated by removing fluid build up from the pleural space via thoracentesis as well as treating the underlying cause.
- Heat stroke will require administration of cool fluids either intravenously or via enema to bring your cat's body temperature down.
- Supportive care may also be necessary in many cases, which include cage rest, fluid therapy, and nutritional support.
- Aspirin toxicity is treated by inducing vomiting (where possible) or gastric lavage (stomach pumping) to reduce exposure to the toxin. Sodium bicarbonate to treat acidosis as well as fluid therapy to help flush the toxin out of the body and correct electrolyte imbalances.
- Activity should be restricted while your cat is recovering.
- Administer all medications as prescribed by your veterinarian.
- Carefully monitor your cat and seek medical help if you notice any changes.
- It is likely that your veterinarian will need follow-up appointments with your cat to monitor his condition.