The risk of infection with feline haemoplasmas has been associated with different factors, such as age, gender, breed, environment, flea infestation and concurrent diseases [10–12, 15, 21]. Our results showed a statistical association between age and carriage of haemoplasma species, with an increased prevalence in older cats. These finding are consistent with findings in previous studies [12, 21, 26]. An association between risk of infection and increasing age may simply reflect a cumulative risk of exposure, since complete clearance of the organism once a cat has become infected has not been demonstrated. We also found higher prevalence of haemoplasma in domestic cats compared to purebred cats. Purebred cats are often held indoor, whereas domestic cats more often allowed being outdoor, where risk of exposure is higher.