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 control; 2) infected, treated with doxycycline; 3) infected, treated with doxycycline and an anti-inflammatory dose of corticosteroid; and 4) infected, treated with doxycycline and an immunosuppressive dose of corticosteroid. Thoracic radiographs were made and ocular fluorescein angiography was performed on days 6, 10, 17 post-inoculation. A mild interstitial lung opacity was noted in 4/16 dogs on day 6, 5/16 on day 10 and 3/16 on day 17 post-inoculation. Increased retinal vascular permeability was noted in 8/16 dogs on day 6, 3/16 on day 10 and 1/16 on day 17 post-inoculation. Correlation between the presence of radiographic and retinal lesions was not significant (p = 0.08). Eleven, naturally infected, dogs with thoracic radiographs and a final diagnosis of RMSF were also evaluated. Four of the 11 dogs had an unstructured interstitial pattern. Dogs with acute, experimentally-infected or naturally-occurring RMSF may have subtle pulmonary changes characterized by an unstructured interstitial pattern.
Drost
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Department of Anatomy, Physiological Sciences and Radiology, College of Veterinary Medicine, North Carolina State University, Raleigh 27606, USA.
Berry
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Breitschwerdt
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Davidson
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D000818:Animals; D004283:Dog Diseases / Q000000981:diagnostic imaging* / Q000188:drug therapy; D004285:Dogs; D005260:Female; D008168:Lung / Q000000981:diagnostic imaging; D008297:Male; D013902:Radiography, Thoracic / Q000662:veterinary*; D012373:Rocky Mountain Spotted Fever / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000662:veterinary*