Signs, Causes, and Treatment of Anemia in Cats

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High Angle View Portrait Of Ginger Cat Sitting On Street
High Angle View Portrait Of Ginger Cat Sitting On Street

Anemia occurs when an animal’s red blood count drops lower than normal. This decrease can be from blood loss, a decrease in number of red blood cells produced, or an increase in number of cells destroyed by the body. Many diseases can cause a cat to become anemic. If the red blood cell count drops quickly or gets very low, the cat may need hospitalization, blood transfusions, and in some cases, anemia can be deadly.

What Is Anemia?

Anemia is symptom of another illness. It occurs when there are not enough healthy red blood cells or hemoglobin in the blood. Hemoglobin is the main component of red blood cells and its job is to carry oxygen. When there are not enough red blood cells or hemoglobin the cells of the body cannot get enough oxygen, so they are unable to work properly. It is this lack of oxygen that causes the signs seen in the cat.

Anemia is divided into two categories: regenerative or non-regenerative. Regenerative anemia means the body is making more red blood cells. Non-regenerative anemia occurs when the body is not making more red blood cells.

silver tabby cat on white textile
silver tabby cat on white textile

Signs of Anemia in Cats

  • Pale gums
  • Increased heart rate
  • Increased breathing rate
  • Lethargy (excessive sleepiness)
  • Weakness
  • Decreased appetite
  • Increased water intake
  • Collapse

In cats, the symptoms of anemia can vary based on how quickly the cat's red blood cell count dropped.

The gums may be pale due to a decrease of oxygen in the blood. A cat's heart rate also increases in an effort to get oxygen to the cells that need it. The breathing rate increases to bring more oxygen into the body, and a cat may also experience lethargy because the decreased oxygen in the blood means there is less energy for the cells so the cat is sleepier.

When cats are anemic, their muscles are unable to get the oxygen they need to function normally, so they may not be able to run, jump, or play. They also lose their appetite when they're anemic and may drink more in an effort to replace lost blood volume. In severe cases when the cat has lost a lot of blood, they may be unable to move or can become unresponsive due to a lack of oxygen to the brain.

person holding white and brown kitten
person holding white and brown kitten

If your cat is showing any of these symptoms, they should be evaluated immediately by a veterinarian.

Causes of Anemia in Cats

Anemia is not an illness, but a symptom of many other illnesses. The different causes of anemia are grouped based on whether the anemia is regenerative or not.

Causes of Regenerative Anemia

Blood Loss:

can occur externally or internally. Blood loss can be caused by trauma or a major injury (like being hit by a car), parasites (like fleas, lice, and hookworms), stomach ulcers (usually associated with kidney failure), and tumors. (Tumors in the spleen or bleeding tumors in the intestinal tract are most common.)

black cat on concrete platform
black cat on concrete platform


The body is destroying red blood cells because they appear abnormal in some way.


The cat eats something accidentally. Toxins can be divided into several groups: Medications, plants like oak, red maple, or bracken ferns, foods like fava beans and onions, and heavy metals like copper, lead, selenium, or zinc.


If you're worried that your cat is anemic as a result of your cat eating something, bring that specific food with you to the vet so the doctor can see exactly what they ingested.


The cat is exposed to a bacteria or virus that can cause anemia. Bacteria, like Hemobartonella, can cause anemia, as can viruses like Feline Leukemia Virus (FeLV) and Feline Immunodeficiency Virus (FIV). Parasites like cytauxzoon and hemotrophic mycoplasma can also cause anemia.

selective focus photography of gray cat
selective focus photography of gray cat

Genetic Diseases:

Anemia can be inherited. The Abyssinian and Somali breeds are known to develop a specific type of anemia due to an enzyme deficiency.

Causes of Nonregenerative Anemia

Poor Diet:

A poor diet can lead to nutritional deficiencies that result in anemia. This is not common in a typical cat.

Chronic Diseases:

Diseases of the liver, adrenal, or thyroid glands, and cancers can all cause anemia. These illnesses cause inflammation, and this inflammation can decrease the body’s ability to make more red blood cells.

brown tabby cat lying on white textile
brown tabby cat lying on white textile

Kidney Disease:

A hormone called erythropoietin stimulates the body to make new red blood cells. This hormone is made by the kidneys. Kidney disease decreases the amount of erythropoietin the kidneys can make.

Bone Marrow Disorders:

The bone marrow is where new red blood cells are made. Any disease affecting the bone marrow can cause anemia. The most common diseases of cats that affect the bone marrow are cancer, feline leukemia virus and feline immunodeficiency virus.

How to Diagnose Anemia

The veterinarian will collect a blood sample to run a Complete Blood Count (CBC). The complete blood cell count will reveal how many red blood cells, hemoglobin, platelets, and white blood cells the cat has. This test also tells the doctor if the anemia is regenerative or not.

focus photography of orange tabby cat
focus photography of orange tabby cat

Once the veterinarian identifies anemia, other tests will be recommended based on the cat’s symptoms to determine what the cause of the anemia is.


Since anemia is a symptom of many other diseases, it is important to find out what disease is causing your cat to be ill. Focus on treating the primary illness and the anemia should improve.

In cases where the anemia is severe or due to a chronic illness, hospitalization and blood transfusions may be necessary.

sleeping brown tabby cat
sleeping brown tabby cat
shallow focus photo of white and gray cat
shallow focus photo of white and gray cat

How to Prevent Anemia

Anemia is a symptom of many diseases so preventing anemia is not always possible, but there are some specific things you can do to decrease the risk for your cat.

  • Use a monthly parasite prevention product that kills fleas, ticks, lice, and intestinal parasites.
  • Keep your cat indoors, or only allow them outside with direct supervision.
  • Feed them a nutritionally balanced cat food.
  • Have them tested for feline leukemia and feline immunodeficiency viruses as recommended by your veterinarian.
  • Prevent access to toxins.
  • Take your cat in for veterinary exams at least once per year and have blood tests done every one to three years to determine their normal values.
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