What Is Feline Infectious Anemia?
Feline infectious anemia, also called hemotropic mycoplasmosis and formerly haemobartonellosis, is an infection of a cat’s red blood cells by tiny bacteria called hemoplasmas. The most important species is Mycoplasma haemofelis, which can cause severe anemia on its own. Two milder relatives, Candidatus Mycoplasma haemominutum and Candidatus Mycoplasma turicensis, often cause little illness unless the cat has another health problem.
The bacteria attach to the surface of red blood cells. The immune system then destroys those tagged cells, so the cat loses red cells faster than it can replace them. Infection is thought to spread mainly through fleas, cat fights and bite wounds, and untested blood transfusions. Outdoor male cats and cats with feline leukemia virus or FIV are at higher risk.
Why it matters
Feline infectious anemia can look almost identical to immune-mediated anemia, but it needs antibiotics rather than long-term immune suppression. A simple PCR blood test usually tells the two apart.
Signs Owners Notice
- Tiredness, hiding, and sleeping more than usual
- Pale pink or white gums, or a yellow tinge to the gums or eyes in some cats
- Poor appetite and weight loss; see cat not eating for other causes
- Fast or open-mouth breathing, especially after mild activity
- A fever during the early, active phase of infection
Diagnosis
Your vet will start with a complete blood count, which usually shows anemia with signs that the bone marrow is trying to respond. The bacteria can sometimes be seen on a blood smear, but they come and go in the bloodstream, so a smear often misses them. A PCR test on a blood sample is the most reliable way to confirm hemoplasma infection and identify the species. Testing for FeLV and FIV is recommended at the same time.
Some infected cats also test positive on a Coombs test, which is why this disease is often confused with immune-mediated hemolytic anemia (IMHA). In IMHA the immune system attacks red cells without an infectious trigger; in feline infectious anemia the bacteria are the trigger, and clearing them is the main goal.
Treatment and Outlook
- Antibiotics: doxycycline for several weeks is the usual first choice. Give each dose with food or follow it with water, because doxycycline tablets can damage a cat’s esophagus. A fluoroquinolone such as pradofloxacin is an alternative your vet may suggest.
- Short-term steroids: sometimes added in severe cases to slow the destruction of red cells.
- Blood transfusion: needed for cats with life-threatening anemia.
- Supportive care: fluids, appetite support, and rest while the bone marrow recovers.
Most cats respond well to treatment, often within days, and the outlook is good when there is no serious underlying disease. Antibiotics do not always clear the infection completely, so some cats stay carriers and can relapse during stress or illness. Cats with FeLV or other serious conditions have a more guarded outlook.
Practical Tips for US Pet Owners
- Use year-round flea control for every cat and dog in the home; see flea treatment for cats.
- Keeping cats indoors reduces fights, bites, and flea exposure.
- Ask about FeLV and FIV status for any new cat joining the household.
- Find a nearby practice through veterinary clinic listings.
When to see a vet
Book a same-day visit for pale gums, sudden weakness, or loss of appetite. Go to an emergency clinic if your cat is breathing fast at rest or collapses.
Key Takeaways
- Feline infectious anemia is a red blood cell infection caused mainly by Mycoplasma haemofelis.
- Fleas, fighting, and blood transfusions are the likely routes of spread.
- PCR testing confirms it, and antibiotics plus supportive care usually work well.
FAQ
Can my cat give feline infectious anemia to me?
The risk to healthy people is considered very low. Good flea control and hand washing after handling bite wounds are sensible precautions.
Can dogs get the same infection?
Dogs have their own hemoplasma, Mycoplasma haemocanis, which usually only causes illness in dogs without a spleen or with a weakened immune system.
Is feline infectious anemia the same as IMHA?
No. IMHA is an immune attack on red cells with no infection behind it. Feline infectious anemia is driven by bacteria and treated with antibiotics.