Infectious Anemia in Cats

Infectious anemia can be transferred to any cat through fleas and ticks that have fed on an infected animal, however cats with weak immune systems are more at risk. This serious health condition needs to be treated with medication, so if you notice the signs of infectious anemia, bring your cat into a veterinarian as soon as possible.

Anemia is the medical term used to describe a low number of red blood cells in the bloodstream. There are different types of anemia that can affect your cat, including infectious anemia, which is caused by bacterial microorganisms that destroy your cat’s red blood cells. Some cats may exhibit very few symptoms, while others may have a more severe case of anemia with easily observable symptoms.

One of the first symptoms cat owners may spot is a fever, which tends to occur in the early stages of infectious anemia. Beside the fever, some of the other symptoms your cat may develop include:

• Loss of appetite
• Weakness
• Lethargy
• Pale mucous membranes
• Depression
• Increased heart and respiratory rates

Infectious anemia is caused by a very specific type of bacteria known as mycoplasma. There are three different types of mycoplasmas that may affect your cat and cause anemia, including:

• Mycoplasma haemofelis
• Mycoplasma haemominutum
• Mycoplasma turicensis

Fleas and tickets can transfer the bacteria to cats after feeding on infected animals. This bacteria often lands on the surface of red blood cells, however attaching to the cell causes irreversible damage, and the cell is destroyed as a result. When these mycoplasmas destroy a large number of red blood cells, it causes anemia. 

Anemia is not easily diagnosed by vets since many conditions can cause the same symptoms. However, you should still provide the vet with a thorough medical history and information on what symptoms you have observed and when they began.

The vet will need to perform a physical exam on your cat to understand what is causing the symptoms. First, the vet will conduct a blood chemistry profile, complete blood count test, and urinalysis to get a better picture of the cat’s overall health. A polymerase chain reaction (PCR) test will also be conducted, which will identify the presence of mycoplasmas in the blood.  Blood smears may also be conducted to allow the vet to look at a sample under a microscope, but these are not as reliable as a polymerase chain reaction test.

Once the vet is able to spot the bacteria in your cat’s blood, he will issue an official diagnosis of infectious anemia. 

Infectious anemia will need to be treated with antibiotics to eliminate the mycoplasmas from the blood. The most effective antibiotic is doxycycline, however tetracycline and oxytetracycline are also reliable. Antibiotics are usually given for a period of three weeks, at which point the cat will need to be checked again to ensure there is no sign of mycoplasmas in the blood.

Because your cat’s body may be accidentally destroying red blood cells in an attempt to fight off the bacteria, the vet may also prescribe corticosteroids to stop the body from doing so. Some vets prefer to try treating infectious anemia with just the antibiotics at first. They may ask you to bring the cat in after a few days have passed to reassess his condition. If there is not an improvement, then corticosteroids may be prescribed.

Cats that have lost a great deal of weight because of the anemia may need supportive care to regain their strength while they recover. Some cats will also need to receive an IV with hydrating fluids to help with dehydration.

If your cat has an extremely severe case of infectious anemia, he may need a blood transfusion to fully recover. However, this is rare and usually avoidable.

You will need to carefully follow your vet’s instructions on how and when to administer antibiotics and corticosteroids to your cat. It’s imperative that you don’t miss any doses otherwise the bacteria may not respond to the medication.

Antibiotics are usually effective in reducing the symptoms of infectious anemia, but that does not mean the harmful bacteria will be completely eliminated from your cat’s body. Your cat may be a carrier for years after being treated, and the anemia may reappear when the cat is going through stress or periods of illness. It’s important to watch your cat carefully to look for signs of a relapse. If you spot any of the same symptoms, bring your cat to a vet for additional treatment.

Because fleas and ticks can transfer the bacteria to cats, it’s important to administer flea and tick prevention medication to your cat on a consistent basis. Talk to your vet about what type of flea and tick prevention you should be using on your cat.