Pyruvate Kinase Deficiency In Maine Coon Cats

When it comes to the condition known as Pyruvate kinase deficiency, Maine Coon cats are, unfortunately, at a higher risk than some other cat breeds.

Thankfully, this disorder is not necessarily a death sentence, but cats with this condition require a lot of extra care.

Pyruvate kinase deficiency is a kind of anemia where the affected cat is unable to produce enough of the enzyme pyruvate kinase. This enzyme produces energy for red blood cells, and without it, their lifespan is reduced. Without sufficient red blood cells, the affected cat will suffer from anemia, leading to weakness, weight loss, and other symptoms.

Sadly, there is no cure for pyruvate kinase deficiency, but a Maine Coon with this condition can still live a long, happy life.

Read on to learn more about how to identify and manage symptoms of pyruvate kinase deficiency.

Pyruvate Kinase Deficiency In Maine Coon Cats

Maine Coons are one of the most popular cat breeds in the entire world, and they are only becoming more popular with each passing year.

This breed became famous for its enormous size, and some Maine Coons have even reached an incredible 35 pounds!

These gorgeous, long-haired cats are not just prized for their appearance; they are also well known for their loving, social nature and patience with children and other pets.

As wonderful as Maine Coons are, they can be prone to a variety of inherited conditions, including pyruvate kinase deficiency.

So, what is pyruvate kinase deficiency?

Also known as PKD, PKdef, or erythrocyte pyruvate kinase deficiency, this disorder is an inherited type of hemolytic anemia.

Hemolytic anemia specifically refers to a kind of anemia where red blood cells are abnormally destroyed or have a reduced lifespan.

Red blood cells are responsible for the transportation of oxygen and iron throughout the body.

Cats that are unable to produce sufficient red blood cells may experience the following:

  • Fatigue
  • Dizziness
  • Jaundice
  • Other Symptoms

PKdef is a specific kind of hemolytic anemia, where the body is lacking the enzyme pyruvate kinase.

This enzyme allows red blood cells to metabolize energy.

In cats with PKdef, this enzyme is not sufficiently active, which means that the affected cat’s red blood cells become unstable and have significantly shorter lifespans.

When it comes to PKdef, Maine Coon cats are more likely to suffer from this condition than many other breeds, although it is most common among Abyssinian and Somali cats.

While there is no way to get rid of PKD, it is possible to catch it early through Maine Coon health tests.

Responsible breeders will conduct genetic testing on all of their cats before breeding them, to prevent passing on any disorders to their offspring (source 1,2,3).

What Causes Pyruvate Kinase Deficiency?

PKdef is an inherited disorder, which means that one of the only causes of pyruvate kinase deficiency is a single pair of genes.

This condition is recessive, meaning that, in order for a cat to have PKdef, it must inherit two copies of the gene.

Both parents must carry at least one copy of the gene for their offspring to have pyruvate kinase deficiency.

If a cat only inherits one copy of the gene from its parents, then it becomes a carrier. This means that, while this cat will not have PKdef, they can still pass it on to their offspring.

So, why is PKdef more common in Maine Coons and some other cat breeds?

Unfortunately, breeding cats to have specific characteristics means that many fanciers will breed cats that are closely related.

When there is only a small selection of cats that have certain desirable characteristics, they are also more likely to pass on genetic disorders to their offspring.

As wonderful as new cat breeds or rare colorations can be, it is important to keep in mind that many emerging cat breeds are the result of inbreeding.

Some cat breeds, such as Persians and Munchkins, are actually the result of unhealthy characteristics.

As cute as Persians may look, their flat faces actually cause severe breathing problems, and their lifespans are often shortened as a result.

Maine Coons developed naturally in the state of Maine, so they are considered healthier than many other cat breeds.

Still, they are more likely to suffer from a variety of inherited conditions than cats that are not of a specific breed.

If you want to learn how to diagnose pyruvate kinase deficiency, the surest way is through genetic testing.

Veterinary laboratories provide tests for a variety of genetic disorders.

To test for PKdef, you simply need to provide a sample of your cat’s DNA, typically a blood sample or a cheek swab.

This sample is then analyzed and will reveal if your cat carries one copy or two copies of the gene responsible for pyruvate kinase deficiency (source 1,2).

PK Deficiency In Cats Symptoms

Pyruvate kinase deficiency is a complicated disorder that can result in a variety of symptoms.

Cats can also experience varying levels of severity of PKdef; some only have mild anemia, while others can have severe anemia.

Typically, symptoms begin between one month and five years, though the common PK symptoms below often begin between 1.5 and 3 years:

1. Intermittent Periods Of Anemia

Depending on the severity of the condition, cats with PKdef typically have wavering periods of anemia, particularly early on.

Without the enzyme pyruvate kinase, the red blood cells are unable to metabolize energy and die off quickly.

Without sufficient red blood cells to carry oxygen throughout the body, the cat will experience anemia.

However, the body is still able to produce red blood cells through bone marrow, and after a period of anemia, a cat may appear to return to normal as more red blood cells enter the bloodstream.

Over time, however, the lack of sufficient pyruvate kinase will cause these red blood cells to die prematurely, as well.

Cats with mild to moderate PKdef will often experience anemia for short periods of time before the body sends out more red blood cells.

Until, eventually, their bone marrow is no longer able to keep up with the continuous loss of red blood cells.

2. Lethargy

Since red blood cells are responsible for transporting oxygen, a cat suffering from PKdef will often feel tired and weak.

You may notice your cat has difficulty playing as it once did, easily becoming exhausted after running or chasing.

Anemia can also cause your cat to breathe rapidly in an attempt to get more oxygen.

3. Pale Gums

Healthy cats have pink gums because their blood is well-oxygenated.

Cats with PKdef, however, lack sufficient oxygen in their blood, and their gums may appear pale.

Other areas of exposed skin may also appear place, such as the:

  • Paw Pads
  • Eyes
  • Ear Flaps

Pale gums can indicate serious illness in a cat, so if you notice this symptom, take your cat to the vet straight away.

4. Jaundice

Red blood cells contain a yellow substance known as bilirubin.

When red blood cells are broken down, they release this substance into the bloodstream.

Since cats with PKdef lose an abnormal amount of red blood cells, they are more likely to contain high amounts of bilirubin, leading to jaundice.

In cats, it is easiest to find signs of jaundice in the following places:

  • Paw Pads
  • Ear Flaps
  • Gums
  • Eyes

5. Loss Of Appetite And Weight Loss

PKdef is likely to cause a loss of appetite or a seeming disinterest in food. As a result, the affected cat can begin to lose weight, as well.

Other underlying conditions, such as hyperthyroidism or cancer, can exacerbate these symptoms and lead to extreme weight loss.

6. Unkempt Coat

Your cat’s coat may appear dull and unkempt.

This is a common sign of illness in cats because, as they struggle with lethargy and lack of appetite, they no longer have the energy to properly care for their fur.

7. Pica

Although more common in cats suffering from iron-deficiency types of anemia, cats with PKdef can also struggle with pica.

Pica refers to the ingestion of inedible objects, most commonly fur and cat litter.

A cat struggling with anemia will try to ingest inedible items to gain more nutrients, in an attempt to replenish its red blood cells.

8. Enlarged Abdomen

A relatively rare sign of PKdef in cats is an enlarged abdomen, due to swelling in the spleen and sometimes the liver.

The spleen traps and removes old red blood cells.

However, since a cat with PKdef suffers from the excessive destruction of these red blood cells, the spleen may be unable to effectively break down all of the red blood cells.

If you notice any worrying symptoms in your cat, you should take them to the vet right away.

Consider Maine Coon genetic testing if you are concerned your cat may be suffering from PKdef.

Knowing for sure if your cat has PKdef is the first step in treating and managing this condition (source 1,2).

PK Deficiency In Cats Treatment

As heartbreaking as a pyruvate kinase deficiency diagnosis can be, it is not a death sentence!

Firstly, PKdef can have varying levels of severity, and cats with mild or moderate anemia can still live long healthy lives.

Sadly, there is no cure for PKdef, but symptoms can still be managed.

Even cats with severe PKdef can benefit from a variety of treatment options.

Below are some treatment options for Maine Coon PK:

Patient-Specific Treatment

There is not one catch-all way to treat PKdef, but it is possible to manage symptoms. This will, of course, vary based on the symptoms present in your cat.

Cats with cardiac problems or breathing difficulties will need very different treatment from cats dealing with weight loss and appetite loss.

Your vet will be able to provide a more comprehensive plan for your cat depending on its unique situation.

Blood Transfusion

It is possible to perform blood transfusions, exchanging your cat’s blood for blood that is rich in healthy red blood cells.

This is typically only done in severe cases, however, and it can be a stressful and uncomfortable process for your cat.


The spleen is responsible for destroying old red blood cells, but since cats with PKdef are in desperate need of red blood cells, the spleen can actually make symptoms worse.

The spleen can also become overloaded with red blood cells and swell in size.

In severe cases, some veterinarians may recommend a splenectomy, which is the removal of the spleen.

It is important to note, however, that splenectomies should not be taken lightly. This is an invasive operation with a risk of death, as well as a long and painful recovery period.

Humane Euthanasia

Many cats with PKdef live long, healthy lives.

However, in more severe cases, the symptoms of anemia are simply too much for a cat to bear.

As much as we all love our pets, it is sometimes kinder to let them go, so they do not have to suffer anymore.

Euthanasia is a big decision, and you might want to consider consulting multiple veterinarians.

After all, every case of pyruvate kinase deficiency is different, and your cat will need unique care depending on its situation.

Is Pyruvate Kinase Reversible?

Sadly, because pyruvate kinase deficiency is a genetically inherited disorder, there is no way to reverse it or get rid of it.

It is possible to treat the symptoms of PKdef, but there is no way to fix the underlying cause of insufficient pyruvate kinase.

Is Pyruvate Kinase Deficiency Fatal?

When faced with a new diagnosis, many owners wonder, is there a cure for pyruvate kinase deficiency?

Sadly, there is no way to cure this disorder, but the situation is not necessarily hopeless!

Unlike dogs, cats with PKdef do not develop liver failure or osteosclerosis, and some can live for many happy years.

Pyruvate kinase deficiency life expectancy varies depending on the situation, as cases can range from mild to severe.

Severe cases of PKdef can lead to premature death, sometimes as early as two years or younger.

Mild or moderate cases, however, often result in intermittent anemia.

This is because, even though the lack of pyruvate kinase does result in the early destruction of red blood cells, the affected cat can still produce red blood cells through their bone marrow.

Their anemia can come in waves, allowing the affected cat time to rest and recover during non-anemic periods.

Surprisingly, in some mild cases, owners may never notice symptoms at all.

The affected cat may suffer from lethargy and other mild symptoms but is still able to function day each day.

As cats with PKdef grow older, however, the disorder will take more and more of a toll on their body.

Senior cats with PKdef will likely die from this condition, but you will still have many long, happy years to spend with your cat (source 1).

Diseases Associated With Pyruvate Kinase

The erythrocyte pyruvate kinase deficiency mutation identified in multiple breeds of domestic cats often leads to a wide array of varying symptoms and complications.

Here are some conditions that PKdef can cause:

  • Anemia
  • Splenomegaly
  • Heart Murmur

Keep reading to discover more about these specific health issues:


The most common disease related to pyruvate kinase deficiency is anemia.

Anemia refers to an insufficient number of red blood cells which, in this case, is caused by the lack of the enzyme pyruvate kinase.

Cats with anemia do not have enough blood cells to carry sufficient oxygen and iron, and will often become lethargic, dizzy, and weak as a result.


The spleen is responsible for destroying old red blood cells.

Since cats with PKdef already do not have enough blood cells, to begin with, the spleen can actually exacerbate this anemia.

The spleen can also become enlarged as it becomes overloaded with “dying” red blood cells, a condition known as splenomegaly.

In severe cases, the spleen may need to be surgically removed.

Heart Murmur

PKdef can also lead to a variety of cardiac problems, including heart murmurs.

Since red blood cells transport oxygen throughout the body, PKdef will not just affect the lungs.

This also affects the cardiovascular system, which can take a big toll on the heart.

How Does Pyruvate Kinase Deficiency Cause Hemolytic Anemia?

There are many different kinds of anemia, including:

  • Iron-Deficiency Anemia
  • Sickle Cell Anemia
  • Hemolytic Anemia

Hemolytic anemia specifically refers to types of anemia where the red blood cells are abnormally destroyed or have a reduced lifespan.

As a result, the body is unable to produce sufficient red blood cells to make up for this loss, leading to anemia.

The cause of hemolytic anemia in pyruvate kinase deficiency is the lack of activity in the enzyme pyruvate kinase.

When fully functional, this enzyme allows red blood cells to metabolize energy.

In cats with PKdef, however, this enzyme is not active enough, and red blood cells become unstable and “die” much faster than they should (source 1).

Common Cat Diseases

Unfortunately, pyruvate kinase deficiency is not the only disorder that Maine Coons can suffer from.

Below is a list of the most common feline disorders in Maine Coons:

Keep reading to learn more about each of these conditions:

Spinal Muscular Atrophy

Like PKdef, spinal muscular atrophy, also known as SMA, is a genetically inherited condition.

Onset typically begins when a cat is between three and four months old when they develop an unusual or swaying gait.

Over time, as the cat’s back muscles atrophy, they progressively lose strength in their back legs and eventually lose the ability to jump and run as they once did.

This is not a deadly disease, however, and cats with SMA can still live long, fulfilling lives.

Full article on Maine Coon spinal muscular atrophy.

Polycystic Kidney Disease

Also known as PKD, polycystic kidney disease is a genetically inherited disorder that causes pockets of fluid, called cysts, to form inside a cat’s kidneys.

Many cats with PKD lead happy lives, but in severe cases, the disease can cause kidney failure and death.

Full article on Maine Coon polycystic kidney disease.

Hip Dysplasia

Hip dysplasia is a condition where a cat’s femur and hip joint are malformed.

As the catwalks, the head of its femur grinds into the hip joint, eventually wearing away the joint and making it lose.

This can occur in one or both of a cat’s hind legs and results in pain and lameness.

This disorder is not fatal and can be managed through pain medications and by providing the affected cat with an accessible living space.

Full article on Maine Coon hip dysplasia.

Hypertrophic Cardiomyopathy

Hypertrophic cardiomyopathy, also known as HCM, causes the walls of a cat’s heart to thicken over time.

While some cats can live for years without any signs, this progressive disorder can often lead to death.

There is, unfortunately, no way to cure this disorder, but there are treatments to manage symptoms.

Full article on Maine Coon hypertrophic cardiomyopathy.

Progressive Renal Atrophy

Also known as PRA, progressive renal atrophy refers to two main kinds of degenerative disorders.

Cats with PRA develop blindness due to a malformed retina or the deterioration of the retina.

While it does lead to partial or complete blindness, cats with PRA can learn to adapt to their disability, and they can still lead very happy lives (source 1,2,3,4).


Pyruvate kinase deficiency in Maine Coon cats may sound scary at first, but this condition can vary greatly in severity, and many afflicted cats live long happy lives.

PKdef results in anemia, as well as possible symptoms like lethargy, weakness, or weight loss.

Although there is no way to cure a cat of PKdef, symptoms can still be treated and managed for many years.

Since pyruvate kinase deficiency is a genetically inherited disorder, it is important to screen all cats before breeding them.

If you plan on purchasing a Maine Coon from a breeder, you should ensure they genetically screen all of their cats before breeding, as well.

Related Questions

PKdef In Bengal Cats

Like Maine Coons, Bengal Cats can also inherit pyruvate kinase deficiency. In order to prevent this condition, it is important to genetically test any parents before breeding them.

SMA In Cats

Spinal muscular atrophy is another genetically inherited condition that can affect Maine Coons. This causes the muscles around a cat’s lower back to atrophy, resulting in weakness and lameness.

Abyssinian Cat Anemia

Abyssinian and Somali cats are the two most likely breeds to inherit PKdef, with about 15% to 30% of both breed populations carrying at least one copy of the gene.

Maine Coon Central

Hello! My name is Katrina Stewardson, and I’m a CRAZY CAT LADY! I've been in love with the Maine Coon cat breed ever since we welcomed an adorable male Maine Coon kitten into our home 10 years ago. We called him 'Pippin', but he also goes by the name ‘Pipsteroo’! Our enormous, kind-hearted cat genuinely thinks he's a dog and has convinced me that cats are Man's True Best Friend! UPDATE: We recently adopted two 4-year-old male Maine Coon cats. They are named Mika and Bali.

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