Effect of treatment with erythromycin and rifampin during the acute stages of experimentally induced equine ehrlichial colitis in ponies.
Sixteen healthy ponies were inoculated IV with Ehrlichia risticii-infected P388D1 mouse monocytes. Of the 16 ponies, 15 developed clinical signs of equine ehrlichial colitis. Twenty-four hours after onset of fever (rectal temperature > 38.8 C), 7 ponies were treated with 25 mg of erythromycin stearate/kg of body weight and 10 mg of rifampin/kg, given orally every 12 hours for 5 days. The remaining 8 ill ponies served as nontreated controls. All ponies were observed for progression of clinical signs typical of equine ehrlichial colitis. Within 12 hours of initiation of treatment, 4 of the 7 treated ponies had rectal temperature < 38.4 C and, within 24 hours, 6 of the 7 ponies had rectal temperature < 38.3C. In contrast, all control ponies had rectal temperature > 39.2 C at 24 hours (P < 0.05). Of the 7 treated ponies, 4 no longer had signs of mental depression after the second day of treatment, and only 1 of the 7 ponies had mild signs of depression after the third day of treatment. In contrast, control ponies had high mental depression score during the observation period (P < 0.05). Feed intake improved in ponies of the treatment group, with feed intake of 4 of the 7 ponies returning to normal; the other 3 ponies were only mildly anorectic by the second day of treatment. Control ponies progressively decreased their feed intake during the observation period (P < 0.05). One control pony and 2 treated ponies developed diarrhea before the treatment/observation period began. Only 1 treated pony developed diarrhea after treatment began. Of the 8 control ponies, 7 developed diarrhea.(ABSTRACT TRUNCATED AT 250 WORDS)
Palmer
J E
JE
Department of Clinical Studies, New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, Kennett Square 19348.
Benson
C E
CE
D000208:Acute Disease; D000818:Animals; D003092:Colitis / Q000188:drug therapy / Q000382:microbiology / Q000503:physiopathology / Q000662:veterinary*; D004359:Drug Therapy, Combination / Q000627:therapeutic use*; D004435:Eating; D016873:Ehrlichiosis / Q000188:drug therapy / Q000503:physiopathology / Q000662:veterinary*; D004917:Erythromycin / Q000627:therapeutic use; D006734:Horse Diseases / Q000188:drug therapy* / Q000382:microbiology / Q000503:physiopathology; D006736:Horses; D012293:Rifampin / Q000627:therapeutic use
D004917:Erythromycin; D012293:Rifampin