Work

Estimating antimicrobial use in Norwegian cattle (2018 – 2023): a quality assessment and error-correction approach for veterinary prescription data

Year: 2026

Type: article

Abstract: The Norwegian Veterinary Prescription Register (VetReg) records all antimicrobials prescribed for food-producing animals in Norway, yet data-quality deficiencies have so far limited its use for quantitative reporting of antimicrobial use (AMU) in cattle. This study assessed the data quality of VetReg, developed a systematic error-correction approach, and estimated AMU in Norwegian cattle from 2018–2023. In total, 698,864 cattle prescription records were extracted from VetReg and assessed for completeness, validity, and timeliness. Error correction comprised harmonization of recorded units with product specifications and replacement of implausible quantities with product-specific mean therapeutic doses. AMU was quantified as mass of active substance per kg cattle biomass and as defined daily or course doses for veterinary use (DDDvet/DCDvet), with intramammary and intrauterine products expressed per 1,000 cows. Data quality improved throughout the study period: missing herd information in veterinarian-reported records declined from 15.6% to 0.1%, agreement between the recorded units of prescribed medicines (e.g., ml, mg, syringe) and the expected product-specific units increased from 86.0% to 94.2%, the proportion of records reported within one week increased from 58.4% to 77.0%, and 94.4% of prescribed quantities fell within product-specific plausibility limits. Reported AMU declined by 5% over the six years, from 1,328 kg (3.6 mg/kg biomass) in 2018 to 1,258 kg (3.4 mg/kg biomass) in 2023. Parenteral use, which comprised 93.3% of mean annual mass-based use, remained stable, whereas dose-based use declined for intramammary products in lactating cows (-29.6%) and dry cows (-34.6%), for intrauterine products (-87.8%) and for oral products (-57.1%). Benzylpenicillin, a narrow-spectrum penicillin, was the most used active substance, with its proportion of total use rising from 80.4% in 2018 to 87.9% in 2023. To our knowledge, this is the first complete prescription-level characterization of AMU in Norwegian cattle, including intramammaries. Although reporting to VetReg is mandatory, previous comparisons with wholesale sales have indicated that not all antimicrobials sold are recorded; these estimates should therefore be interpreted as conservative. Quality-assessment and error-correction frameworks enable granular AMU surveillance from a single prescription-based source and can support targeted antimicrobial stewardship in settings with already low use.

Source: Preventive Veterinary Medicine

DOI: 10.1016/j.prevetmed.2026.107077