title: Synovial lesions in experimental canine Lyme borreliosis.
abstract: Borrelia burgdorferi is the causative agent of Lyme disease, which is mainly characterized by lameness in dogs. More than 95% of naturally infected dogs are asymptomatic or subclinical; however, in experimental studies, histologic synovial lesions are consistently observed in asymptomatic dogs inoculated with B. burdgorferi. This study investigates the ability of a synovial histopathologic scoring system, clinicopathologic data, and polymerase chain reaction (PCR) testing to differentiate between B. burgdorferi-infected and uninfected dogs. Eighteen 18-week-old beagles were subject to challenge with B. burgdorferi-infected wild-caught ticks (Ixodes scapularis), and 4 uninfected dogs served as controls. Infection was confirmed by serology (ELISA) and PCR amplification of B. burgdorferi-specific DNA of skin biopsies taken at the tick attachment site. A synovial scoring system from human medicine was adapted and implemented on postmortem synovial samples to discriminate infected and noninfected animals. Application of this system to elbows and stifles with a cumulative joint score cutoff  > 4 showed a sensitivity of 88.2% and a specificity of 100%, with a positive likelihood ratio of infinity and a negative likelihood ratio of 0.12. Complete blood count, serum biochemistry, urinalysis, urine protein:creatinine, urine PCR, synovial and lymph node cytology, and synovial PCR were evaluated but were not reliable indicators of clinical disease.
authors.affiliation: College of Veterinary Medicine, Department of Pathology, University of Georgia, Athens, GA 30602, USA.
authors.forename: L
authors.initials: L
authors.lastname: Susta
authors.forename: E W
authors.initials: EW
authors.lastname: Uhl
authors.forename: D A
authors.initials: DA
authors.lastname: Grosenbaugh
authors.forename: P M
authors.initials: PM
authors.lastname: Krimer
mesh_terms: D000818:Animals; D001772:Blood Cell Count / Q000662:veterinary; D025065:Borrelia burgdorferi; D003401:Creatine / Q000652:urine; D004283:Dog Diseases / Q000175:diagnosis* / Q000382:microbiology* / Q000473:pathology; D004285:Dogs; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D006652:Histological Techniques / Q000662:veterinary; D018884:Ixodes / Q000382:microbiology*; D016013:Likelihood Functions; D008193:Lyme Disease / Q000175:diagnosis / Q000473:pathology / Q000662:veterinary*; D016133:Polymerase Chain Reaction / Q000662:veterinary; D013583:Synovial Membrane / Q000382:microbiology / Q000473:pathology*
chemical_list: D003401:Creatine