PDA in Cats
There may be no significant symptoms at first until your cat starts to develop a heart murmur

PDA in cats, also called Patent Ductus Arteriosus, is a birth defect and causes early signs of respiratory distress, a very low tolerance for any type of exercise, and coughing.

Coughing in your cat at any time is a very dangerous symptom and should always be treated very seriously.

However, the most telling sign that your kitten has PDA is the lack of growth compared to the rest of the litter.

When it is caught early, several owners still pass it off as nothing serious and will fall into the trap that the kitten is normal.

However, this is a very serious mistake; if it is not treated over fifty percent of kittens will not survive the first year.


Deep blue eyes in catsThe key to controlling PDA in cats is finding it as early as you can

PDA is a birth defect that affects the ductus arteriosus in kittens when it fails to close properly.

When your kitten is born, the blood flows from the right heart through the pulmonary artery and then into their lungs.

The blood will than returns to the left side of your kitten’s heart, and from there it flows to the entire body.

Before your kitten is born and breathing, there is no need for this to operate in order to survive.

As the blood flows from the pulmonary artery through the ductus arteriosus to the aorta.

After birth, the blood pressure changes in your kittens bloodstream which causes the ductus arteries to close permanently.

This then forces the blood to than enter the lungs where oxygen can be exchanged, which is the normal processes.

With PDA in cats, this vessel fails to close completely, and becomes patent, which is a term meaning open. As a result, some of your kitten’s blood bypasses the lungs.

When this occurs, even though the kitten is breathing properly and it appears that there is nothing wrong, they are not getting enough oxygen to meet the demands of their tissues.

But it is also does something else that can be even more dangerous; it is passing extra volumes of blood into their lungs.

At first, this may cause no significant symptoms, unless it causes congestive heart failure, but this continual blood flow through the PDA starts to produce a continuous heart murmur.


There are several potential causes for heart murmurs in a kitten or young cat.

However the symptoms of PDA in cats will be very easy to spot by owners, and fairly easy for a veterinarian to detect in a routine examination.

The first symptom will be breathing distress in your kitten that will be noticeable by comparison to the rest of the litter.

They will not be able keep up with their siblings, and will show a very low tolerance for any type of exercise.

However, this increased blood flow into your pets lungs can do more than just cause a weakness, it can also lead to seizures, although is not common.

An increased flow of blood can reverse the path of the blood flow from right to left where it causes non-oxygenated blood to flow into the aorta to the rear legs of your cat.

This can cause an elevation in the red blood cell counts.

When this happens, the blood becomes very thick and gooey, which can cause a seizure.

But there are two very distinct symptoms that will help identify PDA in cats, coughing, and stunted or a much slower growth.

The first real warning sign is coughing.

Coughing and drooling in cats are perhaps the two largest warning signals that something is seriously wrong, and in this case the coughing is the result of the additional blood in their lungs.

The stunted growth is a result of the shortage of oxygen to their tissues.

Once you notice the lack of exercise and the slower growth, examine their gums. In most all cases you with see the symptom that will finalize PDA; a bluish tint that reflects the lack of oxygen.


Treatments can be very successful in most cases, but the sad fact with PDA in cats is that a lot of owners will ignore their veterinarians as well as the symptoms that your kitten is showing you.

If PDA is ignored and not treated, your kitten only has about a about a fifty percent chance of making it to their first birthday, as it will take their life.

The first form of treatment is the most successful and generally has over a 90 percent success rate, even in the smallest of kittens that are severely impacted.

The key, however, is to listen to your veterinarian and do not wait for the symptoms to appear; by than it may be too late.

Once it is diagnosed, your veterinarian will do surgery to repair the leak or lack of closure.

If some of the symptoms of a difficulty in breathing or coughing have already started, your veterinarian may have to administer treatments first to reduce the accumulation of fluid.

This accumulation very early is typically caused by the left sided heart failure that is a result of the fluid in the lungs.

If surgery is not an option and heart failure has already occurred, there are several drugs that can be given to your cat as well as being placed on a salt restricted diet.

However, even though this may prolong the life of your cat, the long term diagnosis is not promising.

There is one thing that all owners should avoid under any circumstances.

While it is well documented that aspirin has proven to be very effective in closing PDA in premature babies, your kitten is not a baby.

If you give them aspirin, you have just sealed their death, as aspirin is extremely toxic to cats, let alone kittens.

Aspirin toxicity can occur in your cat if they have been given more than 11 mg. or milligrams; toxic levels are at about 35 mg.

A baby aspirin contains 81 mg. of the toxic ingredients, and even one half a baby aspirin is not only toxic, it is lethal.


PDA in cats can appear as if nothing is really wrong with your kitten, but nothing could be further from the truth.

The symptoms will tell you all you need to know about this potentially very dangerous condition, and once identified, you need to have them examined.

Once it is diagnosed and your veterinarian advises surgery, the longer you wait the less chance your cat has of making it to their first year of life.

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