TY - JOUR

T1 - Invited review

T2 - Selective treatment of clinical mastitis in dairy cattle

AU - de Jong, Ellen

AU - McCubbin, Kayley D.

AU - Speksnijder, David

AU - Dufour, Simon

AU - Middleton, John R.

AU - Ruegg, Pamela L.

AU - Lam, Theo J.G.M.

AU - Kelton, David F.

AU - McDougall, Scott

AU - Godden, Sandra M.

AU - Lago, Alfonso

AU - Rajala-Schultz, Päivi J.

AU - Orsel, Karin

AU - De Vliegher, Sarne

AU - Krömker, Volker

AU - Nobrega, Diego B.

AU - Kastelic, John P.

AU - Barkema, Herman W.

N1 - Funding Information: This study was funded by the Canada's Natural Sciences and Engineering Research Council (NSERC) Industrial Research Chair Program granted to Herman Barkema, with industry contributions from Alberta Milk (Edmonton, AB, Canada), Dairy Farmers of Canada (Ottawa, ON, Canada), Dairy Farmers of Manitoba (Winnipeg, MB, Canada), British Columbia Dairy Association (Burnaby, BC, Canada), WestGen Endowment Fund (Abbotsford, BC, Canada), Lactanet (Guelph, ON, Canada), SaskMilk (Regina, SK, Canada), and MSD Animal Health (Boxmeer, the Netherlands). Ellen de Jong was supported by an NSERC CREATE in Milk Quality Program Scholarship. Data collection forms, analytic code, and any other materials used in the review are available from the corresponding author upon reasonable request. No human or animal subjects were used, so this analysis did not require approval by an Institutional Animal Care and Use Committee or Institutional Review Board. The authors have not stated any conflicts of interest. Publisher Copyright: © 2023 American Dairy Science Association

PY - 2023

Y1 - 2023

N2 - Treatment of clinical mastitis (CM) and use of antimicrobials for dry cow therapy are responsible for the majority of animal-defined daily doses of antimicrobial use (AMU) on dairy farms. However, advancements made in the last decade have enabled excluding nonsevere CM cases from antimicrobial treatment that have a high probability of cure without antimicrobials (no bacterial causes or gram-negative, excluding Klebsiella spp.) and cases with a low bacteriological cure rate (chronic cases). These advancements include availability of rapid diagnostic tests and improved udder health management practices, which reduced the incidence and infection pressure of contagious CM pathogens. This review informed an evidence-based protocol for selective CM treatment decisions based on a combination of rapid diagnostic test results, review of somatic cell count and CM records, and elucidated consequences in terms of udder health, AMU, and farm economics. Relatively fast identification of the causative agent is the most important factor in selective CM treatment protocols. Many reported studies did not indicate detrimental udder health consequences (e.g., reduced clinical or bacteriological cures, increased somatic cell count, increased culling rate, or increased recurrence of CM later in lactation) after initiating selective CM treatment protocols using on-farm testing. The magnitude of AMU reduction following a selective CM treatment protocol implementation depended on the causal pathogen distribution and protocol characteristics. Uptake of selective treatment of nonsevere CM cases differs across regions and is dependent on management systems and adoption of udder health programs. No economic losses or animal welfare issues are expected when adopting a selective versus blanket CM treatment protocol. Therefore, selective CM treatment of nonsevere cases can be a practical tool to aid AMU reduction on dairy farms.

AB - Treatment of clinical mastitis (CM) and use of antimicrobials for dry cow therapy are responsible for the majority of animal-defined daily doses of antimicrobial use (AMU) on dairy farms. However, advancements made in the last decade have enabled excluding nonsevere CM cases from antimicrobial treatment that have a high probability of cure without antimicrobials (no bacterial causes or gram-negative, excluding Klebsiella spp.) and cases with a low bacteriological cure rate (chronic cases). These advancements include availability of rapid diagnostic tests and improved udder health management practices, which reduced the incidence and infection pressure of contagious CM pathogens. This review informed an evidence-based protocol for selective CM treatment decisions based on a combination of rapid diagnostic test results, review of somatic cell count and CM records, and elucidated consequences in terms of udder health, AMU, and farm economics. Relatively fast identification of the causative agent is the most important factor in selective CM treatment protocols. Many reported studies did not indicate detrimental udder health consequences (e.g., reduced clinical or bacteriological cures, increased somatic cell count, increased culling rate, or increased recurrence of CM later in lactation) after initiating selective CM treatment protocols using on-farm testing. The magnitude of AMU reduction following a selective CM treatment protocol implementation depended on the causal pathogen distribution and protocol characteristics. Uptake of selective treatment of nonsevere CM cases differs across regions and is dependent on management systems and adoption of udder health programs. No economic losses or animal welfare issues are expected when adopting a selective versus blanket CM treatment protocol. Therefore, selective CM treatment of nonsevere cases can be a practical tool to aid AMU reduction on dairy farms.

KW - antimicrobial use

KW - clinical mastitis

KW - dairy cattle

KW - rapid diagnostic tests

KW - selective treatment

U2 - 10.3168/jds.2022-22826

DO - 10.3168/jds.2022-22826

M3 - Review

C2 - 37080782

AN - SCOPUS:85152912268

VL - 106

SP - 3761

EP - 3778

JO - Journal of Dairy Science

JF - Journal of Dairy Science

SN - 0022-0302

IS - 6

ER -