title: Efficacy of atovaquone and azithromycin or imidocarb dipropionate in cats with acute cytauxzoonosis.
abstract: BACKGROUND
  Imidocarb or a combination of atovaquone and azithromycin (A&A) has been suggested for treatment of cats with cytauxzoonosis, but neither has been prospectively evaluated for efficacy.
  
  
  OBJECTIVE
  That survival to hospital discharge is improved by treatment with A&A as compared with imidocarb.
  
  
  METHODS
  Eighty acutely ill cats with Cytauxzoon felis infection treated at one of 18 veterinary clinics in 5 states.
  
  
  METHODS
  An open-label, randomized prospective study compared survival in cats treated with atovaquone (15 mg/kg p.o. q8h) and azithromycin (10 mg/kg p.o. q24h) or imidocarb (3.5 mg/kg i.m.). All received heparin, fluids, and supportive care. Clinical and clinicopathologic data from initial presentation were collated. Parasitemia was quantified (n = 79) and pathogens genotyped (n = 60). Logistic regression was used to determine the impact of treatment group on the primary endpoint, survival to hospital discharge or death. Covariants were analyzed by rank-sum testing.
  
  
  RESULTS
  Of 53 cats treated with A&A, 32 (60%) survived to discharge while only 7 of 27 cats (26%) treated with imidocarb survived (P = .0036; odds ratio 7.2, 95% CI 2.2, 24). Cats with a lower parasitemia were more likely to survive, as were cats with higher white blood cell counts and lower total bilirubin. Unique pathogen genotypes were identified from 15 cats, while genotype isolated from 21 cats had been described previously. There were multiple pathogen genotypes identified in 24 cats.
  
  
  CONCLUSIONS
  Survival to discharge was more likely in cats treated with A&A as compared with imidocarb, although case fatality rate remained high.
authors.affiliation: Department of Veterinary Medicine and Surgery, University of Missouri, Columbia, MO 65211, USA. cohnl@missouri.edu
authors.forename: L A
authors.initials: LA
authors.lastname: Cohn
authors.forename: A J
authors.initials: AJ
authors.lastname: Birkenheuer
authors.forename: J D
authors.initials: JD
authors.lastname: Brunker
authors.forename: E R
authors.initials: ER
authors.lastname: Ratcliff
authors.forename: A W
authors.initials: AW
authors.lastname: Craig
mesh_terms: D000818:Animals; D000981:Antiprotozoal Agents / Q000627:therapeutic use*; D053626:Atovaquone / Q000627:therapeutic use*; D017963:Azithromycin / Q000627:therapeutic use*; D002371:Cat Diseases / Q000188:drug therapy* / Q000469:parasitology; D002415:Cats; D016054:DNA, Protozoan / Q000737:chemistry / Q000235:genetics; D004359:Drug Therapy, Combination / Q000662:veterinary; D005260:Female; D005838:Genotype; D007095:Imidocarb / Q000031:analogs & derivatives* / Q000627:therapeutic use; D016015:Logistic Models; D008297:Male; D018512:Parasitemia / Q000188:drug therapy / Q000469:parasitology / Q000662:veterinary; D016792:Piroplasmida / Q000235:genetics / Q000302:isolation & purification*; D016133:Polymerase Chain Reaction / Q000662:veterinary; D011446:Prospective Studies; D011529:Protozoan Infections, Animal / Q000188:drug therapy* / Q000469:parasitology; D016019:Survival Analysis
chemical_list: D000981:Antiprotozoal Agents; D016054:DNA, Protozoan; D017963:Azithromycin; D007095:Imidocarb; D053626:Atovaquone; C031719:imidocarb dipropionate