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Anemia in Cats

cat_standingCats with low red blood cell count or poorly functioning red cells become pale, a condition we call anemia. The blood really is the "life-blood" for the cat! Without enough red cells to grab oxygen molecules during their trip through the lungs, Kitty is in trouble!

At home, a caregiver may notice the cat is pale when the cat yawns. Instead of a nice healthy pink tongue and gums, a pale whitish appearance is noted. Note that cats normally have pale pink gums, so the tongue is actually a better barometer for checking color.

If you suspect your cat is paler than usual, you can gently move the eyelid away from the normal position to expose the conjunctivae, or the mucous membranes surrounding the eye under the lid margins. These are also normally a light pink, but may appear ghostly white in an anemic cat. The third eyelid will pop up from the inside corner of the eye if you put pressure around the eyelids, and this is normally quite pale so this is not the best place to monitor membrane color.

If there is any likelihood the cat is paler than normal, a visit to the veterinary hospital for a professional assessment is in order. Cats with anemia may be weak and lethargic, sleep more than usual, and if they exert themselves, they may need to open-mouth breathe to catch their breath. They may also breathe faster than normal. Certain types of anemia may cause fever and discolored urine.

Diagnosis of Feline (Cat) Anemia

The veterinarian will take a complete blood count (CBC) sample to check the red blood cell count, red blood cell appearance, and other key blood parameters. Other tests may also be recommended such as a Feline Leukemia Virus/Feline Immunodeficiency Virus combo screen, urine analysis, and a blood chemistry panel.

Note that in most cases, it is an abnormal CBC test that will be the first indicator of an emerging anemia condition. The cat may appear quite normal still at home, but the cell count tells another story! A professional assessment of the cat may also provide the first clue, as your veterinarian is very experienced in assessing the mucous membrane color of cats and will often pick up subtle changes in color during the routine physical examination. This may then trigger a recommendation for further testing.

The severity of anemia may range from mild to moderate, to extreme (life threatening), and may wax and wane in certain conditions. Routine wellness testing is an important means for your veterinarian to help check your cat for early signs of anemia. In a best case scenario, early intervention will prevent progression to the advanced stages.

What Causes Anemia in Cats?

The most common reasons for anemia are reduced or abnormal red blood cell production by the bone marrow, or loss or destruction of functioning red cells. Whether the anemia shows signs of regenerative response or not is also an important consideration. Regeneration means that the bone marrow is healthy.

Some specific anemia conditions include:

  • Kidney failure. Anemia of chronic failure is primarily associated with reduced stimulation of bone marrow to produce red cells due to low production of the hormone erythropoietin
  • Hemoglobin oxidation. Hemoglobin carries the oxygen inside the cell so reduced function of the hemoglobin leads to Heinz body anemia or methemoglobinemia. Oxidation interferes with red cell function.
  • Blood parasites (such as Mycoplasma haemofelis and Mycoplasma haemominutum, formerly called Haemobartonella felis)
  • Blood type incompatibility hemolytic anemia; where red cells burst (neonatal isoerythrolysis, transfusion reactions)
  • Virus-associated or drug-related bone marrow disorders (aplastic anemia, or larger than normal red blood cells produced in FeLV-infected cats)
  • Parasites. Hookworms or fleas (heavy infestations, especially in kittens)
  • Trauma blood loss (hit-by-car, deep penetrating wounds)
  • Abnormal red cell production due to inherited conditions (osmotic fragility syndrome, Pyruvate Kinase deficiency, congenital porphyria)
  • Uncommonly, see iron deficiency anemia of kittens (5-10 weeks old; is transient)

Oxidation is seen with:

  • certain drugs [acetaminophen]
  • dietary components [onion, propylene glycol]
  • toxins [zinc toxicity, moth ball toxicity]
  • diseases [complicated diabetes-ketoacidosis, lymphoma cancer]

How is Anemia in Cats Treated?

Sometimes anemia is so severe that blood transfusions are required. Note that blood is typed in cats before transfusions are done to help reduce the chance of incompatible blood being selected.

In other less severe cases, supportive care is offered while the cat responds to the toxicity, blood loss, or other situation leading to the low red cell counts. Erythropoietin replacement is sometimes used for cats with chronic kidney failure. For some types of anemia, there are no effective treatments. This may be the case with certain cancers or terminal infections that damage cell production in the bone marrow.

Your veterinarian will help you understand the cause of your cat’s anemia, the expected prognosis, and will monitor your cat closely to help determine whether therapy is effective.

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