Candidatus M. haemominutum PCR in a cat with severe haemolysis
3-year-old neutered male cat, kept indoors with access to a terrace, presenting with lethargy, pale mucous membranes and mild jaundice. FeLV (antigen) and FIV (antibody) negative, no recent drugs, abdominal ultrasound without neoplasia. The laboratory returns the haemoplasma PCR panel.
| Parameter | Result | Reference |
|---|---|---|
| Haematocrit | 11% | 30–45 |
| Aggregate reticulocytes | 165,000/µL | < 50,000 |
| Total bilirubin | 2.1 mg/dL | 0.1–0.4 |
| Saline autoagglutination | Positive and persistent | Negative |
| Mycoplasma haemofelis PCR | Negative | Negative |
| Candidatus M. haemominutum PCR | Positive | Negative |
What is the most appropriate interpretation and approach?
chevron_right Show answer and explanation
A. CMhm explains the haemolysis: 4 weeks of doxycycline and no other drugs
Candidatus M. haemominutum has low pathogenicity: in an immunocompetent cat it rarely causes more than mild anaemia. Treating only the haemoplasma leaves a severe immune-mediated destruction uncontrolled.
B. CMhm does not explain it: treat as IMHA with glucocorticoids
Correct. With negative FeLV/FIV, no drugs or neoplasia and persistent autoagglutination, IMHA is most likely; CMhm is often a concurrent finding. Feline IMHA usually responds well to prednisolone; doxycycline can be added meanwhile.
C. A positive haemoplasma rules out IMHA: glucocorticoids are contraindicated
Infection and immune-mediated disease are not mutually exclusive: haemoplasmas can trigger immune-mediated destruction and doxycycline and glucocorticoids are often combined. The PCR rules nothing out on its own.
D. Imidocarb, the drug of choice against haemotropic mycoplasmas
Imidocarb is used against Babesia, not haemoplasmas. When a haemoplasma needs treatment, doxycycline (or pradofloxacin or marbofloxacin) is used.
lightbulb Key takeaway
Mycoplasma haemofelis is the truly pathogenic feline haemoplasma; CMhm and Candidatus M. turicensis usually cause mild disease unless there is immunosuppression or co-infection (FeLV). In cats, a 'low-pathogenicity' haemoplasma should not close the diagnosis of severe anaemia.
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Updated: November 1, 2026 · Educational content for veterinary professionals. It does not replace current clinical guidelines or the judgement of the attending veterinarian.