Aplastic Anemia in Cats

A cat suffering from aplastic anemia will begin to experience a lack of oxygen in the body. This prevents all organs from operating at their full capacity. Certain bone marrow issues that lead to aplastic anemia involve underdeveloped bone marrow being replaced by fat. In other cases, kidney failure may result in minimal or no production of erythropoietin, which is a hormone that stimulates red blood cell creation. Aplastic anemia represents 80 percent of all anemia diagnoses in cats. 

Cats need a specific amount of red blood cells in the body to transport the hemoglobin molecule to all body parts for oxygenation. The average life cycle of a red blood cell is approximately two months. At this point, bone marrow (spongy tissue inside the bones) recycles the hemoglobin molecules, while the liver and spleen purify and produce more red blood cells. If the cat is suffering from a condition that damages the bone marrow, the stem cells inside the marrow may be adversely affected and slow or halt hemoglobin production. This results in an abnormally low amount of red blood cells in the body; a condition known as aplastic anemia.

If a cat is severely anemic, it will begin to exhibit signs of oxygen starvation. General exhaustion is often the first notable symptom, as the cat does not have enough red blood cells for normal bodily functions. Signs to watch for are listed as follows:

• Loss of appetite
• Pale or white gums
• Rapid breathing
• Elevated heart rate
• Inability to exercise
• Lethargy
• Confusion
• Collapse

Any condition or external source that leads to bone marrow issues or poor kidney function can cause insufficient red blood cell production. Known causes include:

• Bone marrow disease
• Benign or malignant tumors of the bone marrow or kidneys
• Chronic kidney disease
• Toxin exposure
• Chemotherapy
• Radiation
• Medication
• Hormone administration
• Viral infections (such as feline leukemia virus)
• Bacterial infections (such as ehrlichia)
• Genetic predisposition

If your cat begins to exhibit symptoms of anemia, bring it to your veterinarian at once. Be sure to provide the vet with your cat's full medical history to assist in identifying possible underlying causes of the condition. Full blood work can reveal all cell counts in the bloodstream. A complete blood count including a packed cell volume (PCV) test can provide the percent of red blood cells in a whole blood sample. For this test, the plasma is separated from the red blood cells and then both are measured. Healthy cats contain 25-45% of red blood cells in their blood. Anything less than this indicates the cat is anemic. The actual numerical red blood cell and hemoglobin counts can also be performed microscopically by a lab. 

The cat should be tested for any bacterial infections that could be causing limited red blood cell production. A urinalysis can shed light on both liver and kidney function. A coagulation panel and a buccal mucosal bleeding time (BMBT) test may be run to assess how well the blood is clotting. An abdominal x-ray may be requested to check for the presence of tumors, ulcers or any internal bleeding that could be affecting the bone marrow or kidneys. If tumors are found, biopsies may be needed to check for cancer. Abdominocentesis will be performed if any fluid is present in the abdomen. A DNA test will reveal any genetic problems in the cat. The cat should also be tested for feline leukemia virus.

The first task when treating a severely anemic cat is to restore the proper blood counts and blood volume. This may require supportive care to stabilize the cat. Once this is accomplished, the underlying cause of the anemia can be addressed and potentially treated. 

Supportive Care 

This often involves intravenous fluid administration to boost blood volumes. Fluid should be given slowly to prevent a poor reaction from the cat. Hospitalization is required for this process.

Blood Transfusions 

If blood has been lost, or if blood counts are dangerously low, a blood transfusion may be needed. This may involve a transfusion of whole blood, platelets, packed cells or fresh plasma. 

Antibiotics 

If bacteria has been found causing infection in the cat, a specific antibiotic will be prescribed to counteract the bacteria. This prescription will generally last 1-4 weeks. 

Vitamin K Injection 

If the cat is unable to clot blood due to aplastic anemia, an injection of Vitamin K may be given to aid the clotting process. 

Medication 

Certain medication may be prescribed to stimulate the growth of bone marrow. While this is not a permanent solution, it can improve the situation for a period of time.

Bone Marrow Transplant 

If bone marrow issues are caused by feline leukemia virus, a bone marrow transplant may be an effective treatment method. It is not always offered, as not all veterinary clinics perform the surgery. Cats who undergo this surgery generally experience minimal complications.

The permanent restoration of proper blood cell counts in cats can only be achieved in certain circumstances. The overall outcome will vary greatly depending on the underlying cause of aplastic anemia that has been diagnosed. If symptoms had a rapid onset, often the condition is reversible. If the anemia has existed for a long period of time, the underlying issue is often more complicated. 

If the cat has undergone surgery, be sure to provide all at-home care as it has been instructed. Monitor any incision sites daily to ensure that they are clean and free of infection. All medications should be administered as prescribed. If cancer has been diagnosed, ongoing treatment and further surgeries may be needed. The cat will need follow-up appointments with the veterinarian to test if red blood cell levels are rising properly.