Cat Feline Infectious Anemia: Managing Mycoplasma Infection

Feline infectious anemia caused by Mycoplasma haemofelis is a tick-associated blood parasite that destroys red blood cells, causing potentially severe anemia requiring antibiotic treatment and sometimes supportive transfusion.

Key Facts

Feline infectious anemia (FIA) is caused by Mycoplasma haemofelis and related hemoplasmas
The parasite attaches to red blood cell surfaces, causing immune-mediated destruction and anemia
Transmission occurs through fleas, ticks, and cat bites - blood-sucking parasites are primary vectors
Clinical signs include lethargy, pale or yellow gums, anorexia, and sometimes fever
PCR testing is the gold standard diagnostic as organisms may be too few to see on blood smear
Doxycycline for 4 weeks is the treatment of choice for M. haemofelis infection
Blood transfusions are required for cats with life-threatening anemia before antibiotic therapy takes effect
FIV-positive and FeLV-positive cats are at higher risk for severe disease due to immune suppression
Cats may remain carrier-positive after treatment - stress can cause recurrence in recovered cats

Welfare Considerations

Cats with FIA experience the weakness and breathlessness of severe anemia while their immune system compounds the problem by destroying infected red blood cells. Blood transfusion in critically anemic cats is an immediate welfare intervention that stabilizes them while doxycycline eliminates the infection. Flea and tick prevention is the most effective welfare protection - eliminating the vector eliminates the transmission pathway. FIV-positive cats who develop FIA face compounded immune suppression requiring more aggressive management and closer monitoring.

What You Can Do

Maintain year-round flea and tick prevention for all cats - this prevents FIA and many other vector-borne diseases
Recognize severe anemia signs in cats: pale or white gums, extreme weakness, open-mouth breathing
Seek emergency veterinary care immediately for cats showing severe anemia signs
Request PCR testing for hemoplasmas in cats with unexplained anemia before starting treatment
Complete the full 4-week doxycycline course even if the cat improves rapidly
Monitor for recurrence especially during stressful events in cats with previous FIA episodes