Blood samples collected from 67 Danish cats were investigated to estimate the prevalence of carriage of the three haemoplasmas, CMhm, Mhf and CMt. For each cat, information about breed, gender, age and symptoms/diagnosis were obtained when possible (Additional file 1: Table S1). The haemoplasmas are non-culturable in vitro and accurate diagnosis is currently reliant on detection of bacterial DNA using PCR assays . Eleven animals were found to be positive among the 67 cats tested (Table 1). Ten cats were positive using both conventional and RT-PCR while one additional cat was positive by RT-PCR only. Carriage of multiple haemoplasma species was not detected. From four PCR negative cats [cats 4, 5, 10, 15 (Additional file 1: Table S1)], more than one sample was analyzed [samples 51, 11, 38, 29, 41 and 55 (Additional file 1: Table S1)], and all samples yielded the same negative result upon repeated testing.Table 1Haemoplasma prevalence in blood from 67 cats in Denmark determined by PCR and RT-PCRSpeciesPositive by PCRPrevalence PCR (%)95% CIPositive by RT-PCRPrevalence RT-PCR (%)95% CIMhf11.50–4.411.50–4.4CMhm913.45.2–21.61014.96.4–23.4CMt00Total1014.96.4–23.41116.47.5–25.3 Mhf Mycoplasma haemofelis, CMhm Candidatus Mycoplasma haemominutum, CMt Candidatus Mycoplasma turicensis, CI confidence interval