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Feline haemoplasmosis: real veterinary cases

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Feline haemoplasmosis (historically called feline infectious anaemia) is caused by Mycoplasma species — Mycoplasma haemofelis is the most pathogenic — that attach to red blood cells and trigger the immune system to destroy them. The result is regenerative haemolytic anaemia, often severe, with pale gums, lethargy, weakness, jaundice, and sometimes fever. Outdoor cats, FIV/FeLV-positive cats, and young male cats are at highest risk; transmission is thought to involve fleas and cat bites.

Diagnosis is by PCR on whole blood — far more sensitive than the old blood-smear method (organisms detach during slide prep). Treatment is doxycycline (often 4-6 weeks), supportive care (fluids, transfusion if PCV is critically low), and addressing co-infections (FeLV/FIV). Most cats respond well, but a chronic carrier state can persist and flare under stress.

What vets typically check for

  • CBC — regenerative anaemia (low PCV, reticulocytes up), often with autoagglutination.
  • Blood smear — Mycoplasma sometimes visible but PCR is far more sensitive.
  • PCR on whole blood for M. haemofelis, M. haemominutum, M. turicensis.
  • FeLV/FIV testing — co-infection is common and worsens prognosis.
  • Doxycycline 5 mg/kg PO q12h for 2-4 weeks, with food to avoid oesophagitis.

Not a replacement for veterinary care. Use this to walk into the conversation prepared, not to self-diagnose.

Real cases from the veterinary literature

Peer-reviewed reports our semantic search surfaces for Feline haemoplasmosis (Mycoplasma anaemia). Click into any case for the full abstract — or run a personalised search with your pet's exact details.

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Frequently asked questions

How does my indoor cat catch it?
Mostly through fleas (which is why year-round flea prevention matters even for indoor cats) or, less commonly, through aggressive contact with infected cats. Blood transfusions can also transmit it if donor cats aren't screened. Direct PCR screening of donor blood is standard at most clinics.
Is it dangerous to my other cats?
It can spread between cats via fleas or bite wounds. Treating affected cats, strict flea control, and avoiding direct cat-to-cat blood contact (preventing fighting) minimises spread.
Does treatment cure it?
Doxycycline resolves clinical disease in most cats, but some become latent carriers and can relapse during immunosuppression. Long-term, treated cats usually do well; severely anaemic cases may need transfusion to survive the acute phase.

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