Anemia Due to Red Blood Cell Damage in Cats

PetMD Editorial
By PetMD Editorial on Aug. 12, 2008
Anemia Due to Red Blood Cell Damage in Cats

Anemia, Heinz Body in Cats

This is a condition in which red blood cells are destroyed. The "Heinz body" can be seen under a microscope. This type of anemia can occur as a reaction to certain medications, or as a result of eating onions. It is more likely to occur in cats than dogs, and is usually caused by something the pet has eaten or drunk. Hyperthyroidism, lymphoma, and diabetes may also bring on this condition.


  • Fever
  • Sudden onset of weakness
  • Loss of appetite (anorexia)
  • Reddish brown urine if the case is severe
  • Pale mucous membrane (e.g., lips, mouth, gums)
  • Discoloration of the skin


  • Ingestion of toxins: wilted red maple leaves, kale, turnips, zinc, onions, garlic
  • Drugs: acetaminophen, vitamin K, Phenothiazine, Benzocaine, Phenacetin
  • Diabetes
  • Hyperthyroidism
  • Inherited disorders


First, your veterinarian will do a complete blood count to determine the cause of the symptoms. If Heinz bodies are identified, a course of treatment will be recommended. A methylene blue, or other type of stain to look for Heinz bodies, will be used to determine their exact count. If your cat is very pale, a methemoglobin test will be conducted to measure oxygen in the blood.

It is also important to note that cats may have a significant number of Heinz bodies in their blood without having anemia.


If the source of the Heinz body reaction can be identified, the first step will be to treat the underlying cause. For example, if the offender is acetaminophen, drugs will be prescribed to counteract its effects. Often, this is a sufficient course of treatment.

If the anemia is severe, your cat will be hospitalized and given a blood transfusion and oxygen. It is important that the cat be kept calm while it is sick.

Living and Management

Prognosis is positive once the crisis has been dealt with. Once you know what has caused this illness, you can take steps to keep it from happening again. For example, avoid feeding cats anything with onions or garlic in it. Even flavoring that contains onion or garlic will cause problems (e.g., garlic or onion salt). In addition, be very careful about other people foods your give to your cat. Finally, you will need to take your cat to the veterinarian for occasional monitoring of the clinical measures.

Image: VGstockstudio via Shutterstock

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