THORACIC RADIOGRAPHIC FINDINGS IN DOGS INFECTED WITH RICKETTSIA RICKETTSII

Sixteen beagle dogs were injected intradermally with Rickettsia rickettsii. The dogs were divided into four groups (n=4):1) infected, non-treated withdoxycycline;3) infected, treated with doxycycline and an anti-inflammatory dose of corticosteroid;4) infected, treated with ocular fluoresein angiograhphy was performed on days 6, 10, 17 post-inoculatin.A mild interstitial lung opacitywas noted in4/16 dogs on day 6, 5/16 on day 10 and 17 post-inculatin. Increased retinal vascular permeability was noted n 8/16 dogs on day 6,3/16 on day 10 and 1/16 on day 17 post-inoculation. Correlatin between the presence of radiographic and retinal lesions was not signigicant (p=0.08). Elevan, naturally infected, dogs with thoracic radiographs and an final diagnosis of RMSF were also evluated. Four of the 11 dogs had an unstructu4red inteerstitial pattern. Dogs with acute, experimentally-infected or naturally-occurring RMSF may have subtle pulmonary changes characterized by an unstructured interstitial patteern.