Mycoplasma haemofelis is a blood parasite of cats that can cause a severe regenerative anaemia. This parasite was formerly known as Haemobartonella felis but is now classified as a mycoplasma. Although infected cats may not show signs of clinical disease, in association with other agents (or immunosuppression) M. haemofelis can cause significant disease including potentially fatal anaemia. Common symptoms are intermittent fever, lack of appetite, depression, lethargy and pallor. Symptoms can be more severe when associated with other conditions such as Feline Leukaemia Virus infection.
A related organism of lesser pathogenicity, Candidatus M. haemominutum, is also detected and reported separately in this assay. The pathogenicity of C M. haemominutum is not fully understood. However, it is recommended that cats positive to either organism and showing clinical signs be treated. These mycoplasmas should be considered as potential complications in cats that have been shown to be positive for Feline Immunodeficiency Virus or Feline Leukaemia Virus.
The detection of Mycoplasma in a blood sample should not necessarily be interpreted as that organism being the primary cause of the disease. Other causes of anaemia should be excluded including blood loss into the gut, effusions, neoplasia and chronic viral infections.
The frequency of M. haemofelis infection in a normal cat population, including Candidatus Mycoplasma haemominutum, has been reported to be as high as 40%. The published figures however vary greatly as a result of the lack of sensitivity of the conventional blood smear method and differences in methodologies of the PCR assays published to date.
Traditionally, M. haemofelis has been detected by staining freshly prepared blood smears with Wright-Giemsa stain and examining for the presence of parasites on the erythrocytes. This often gives an equivocal result, as the parasites tend to fall off the erythrocytes soon after the blood is taken making an accurate diagnosis difficult. PCR testing is significantly more sensitive and specific than examination of a blood smear.
Whole blood (minimum 1 ml)
EDTA (purple top) tube
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Tasker S, Binns SH, Day MJ et al.: Use of a PCR assay to assess the prevalence and risk factors for Mycoplasma haemofelis and ‘Candidatus Mycoplasma haemominutum’ in cats in the United Kingdom. Vet Record (2003) 152(7): 193-198.
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