Febrile Illness Associated withRickettsia conoriiInfection in Dogs from Sicily

We report serologic and molecular evidence of acute, febrile illness associated with Rickettsia conorii in 3 male Yorkshire terriers from Sicily (Italy).R ickettsia conorii, transmitted by Ripicephalus san- guineus, causes Mediterranean spotted fever (MSF) in humans in Mediterranean countries, Sub Saharan Africa and Asia (1).Rickettsia spp.seroprevalence in dogs is high (26%-60%) in disease-endemic regions, and proximity to seroreactive dogs is a risk factor for MSF in humans (2,3).Recent studies reported the detection of Rickettsia DNA in the blood of European dogs (4,5).However, evidence that R. conorii infection causes illness in dogs is lacking (2,3,6).Illness has been associated with R. conorii natural infection in only 2 dogs since human MSF was described in 1932 (6).Moreover, the only clinical signs observed in experimentally infected dogs were pain, erythema, and edema at the injection site; and regional lymphadenopathy (6).We report infection with R. conorii ssp.conorii in 3 acutely ill, febrile Yorkshire terrier dogs, supported by PCR, DNA sequencing, and seroconversion.