Horse DiseasesDelayed DiagnosisPrenatal DiagnosisEarly DiagnosisSensitivity and SpecificityDiagnosisRetrospective StudiesEquidaeDiagnostic ErrorsAfrican horse sickness virusLameness, AnimalBiopsyTomography, X-Ray ComputedColicNursing DiagnosisTime FactorsDiagnosis, Computer-AssistedPredictive Value of TestsReproducibility of ResultsFatal OutcomePolymerase Chain ReactionProspective StudiesPreimplantation DiagnosisPregnancyTreatment OutcomePrognosisRisk FactorsFollow-Up StudiesMagnetic Resonance ImagingInfant, NewbornHoof and ClawEquine Infectious AnemiaPerissodactylaEnzyme-Linked Immunosorbent AssayBiopsy, NeedleFetal DiseasesAge FactorsPhysical Conditioning, AnimalIncidenceCohort StudiesPrevalenceInfectious Anemia Virus, EquineBiological MarkersAcute DiseaseFalse Positive ReactionsCase-Control StudiesClinical Laboratory TechniquesUltrasonography, PrenatalROC CurveUnited StatesSeverity of Illness IndexFalse Negative ReactionsSyndrome