Cat Feline Infectious Anaemia Welfare

Feline infectious anaemia caused by Mycoplasma haemofelis is a tick-transmitted bacterial disease that destroys red blood cells, causing potentially life-threatening haemolytic anaemia.

Key Facts

Feline infectious anaemia (FIA) is caused by the haemotropic mycoplasma M. haemofelis, transmitted primarily by fleas and ticks
The parasite attaches to and destroys red blood cells, causing immune-mediated haemolytic anaemia
Clinical signs include pale or yellow gums, lethargy, rapid breathing, weakness, and weight loss
Diagnosis is by blood smear examination or PCR testing — blood smear sensitivity is lower and misses many infections
Treatment with doxycycline antibiotics is effective — most cats respond within 1-2 weeks
Concurrent FeLV or FIV infection dramatically worsens prognosis — FIA in an immunocompromised cat carries high mortality

Welfare Considerations

FIA causes significant acute welfare suffering through the consequences of severe anaemia — extreme fatigue from tissue oxygen deprivation, breathlessness, and weakness that leaves affected cats unable to perform normal activities. Cats with packed cell volumes below 15 percent are in genuine physiological crisis. The immune response that destroys the red blood cells (similar to immune-mediated haemolytic anaemia) adds further complexity to management. Blood transfusion may be required in severely affected cases to stabilise haematocrit while antibiotics take effect. The welfare improvement with treatment is typically rapid and dramatic — most cats show clinical improvement within days of starting doxycycline, with full resolution of anaemia over 2-4 weeks.

What You Can Do

Maintain year-round flea and tick prevention to reduce FIA transmission risk — these ectoparasites are the primary vectors
Seek same-day veterinary assessment for any cat showing pale or yellow gums, lethargy, or rapid breathing
Ensure FIA diagnosis includes PCR testing rather than blood smear alone — PCR sensitivity is significantly higher
Retest cats for FIA status 3-4 weeks after completing doxycycline treatment — a proportion remain persistently positive