Microbiology

Recent updates enable Antech to report minimal inhibitory concentrations (MICs) and susceptibility results using most up-to-date veterinary-specific Clinical and Laboratory Standards Institute (CLSI) guidelines rather than human breakpoints. This change aims to support veterinarians in making more accurate treatment decisions and emphasizes responsible antimicrobial use. Additionally, these updated reports are exclusively available in HealthTracks. Not registered for HealthTracks? Click to learn how to register today.

The Clinical and Laboratory Standards Institute (CLSI) is an international, non-profit organization that develops consensus-based guidelines for laboratory testing, including microbiology and antimicrobial susceptibility testing (AST). CLSI brings together veterinary and human health experts to set evidence-based standards that ensure lab results are accurate, clinically meaningful, and reproducible across different settings. CLSI publishes veterinary-specific documents (e.g., VET01, VET02, VET06, VET09 in Further Reading) that outline species-specific testing methods, breakpoints, and interpretive criteria for dogs, cats, horses, and more.

CLSI has updated its veterinary antimicrobial susceptibility testing guidelines to improve the accuracy and relevance of MIC interpretation for animals. Key changes to the antimicrobial susceptibility testing guidelines include:

1. Veterinary-specific breakpoints for species like dogs and cats
2. New “Susceptible, Dose-Dependent (SDD)” category for dose-adjusted treatment options
3. Revised breakpoints for select drug-pathogen combinations
4. Clearer reporting standards to support consistency and clinical decision-making

Antech now provides suggested prescribing tiers for antimicrobials under the categories Avoid, Restrict, Caution, and Prudence to guide selection and support stewardship. These are assigned to the medication based on risk of antimicrobial resistance and importance to human health.

We chose EMA (European Medicine Agency) categories for their straightforward guidance: their source is less important than their practical role in promoting thoughtful, responsible antimicrobial use for every patient case. (See Interpretation for how to use them.)

Every patient is unique and safe, effective dosing depends on many factors. These include, for example, kidney and liver function; owner compliance and practicality—along with many others. To help tailor treatment, we encourage you to consult trusted references like Plumb’s
Veterinary Drug Handbook, ISCAID, or ACVIM guidelines, and other pharmacology resources. For especially complex cases, specialist input can be invaluable.

AntechOnline is our legacy platform and is no longer being enhanced. To best support veterinarians, Antech is investing in HealthTracks—our one digital diagnostic platform designed to deliver continuous innovations, streamlined workflows, and enhanced reporting. HealthTracks provides the comprehensive diagnostic support our customers need, while AntechOnline cannot fully support these growing requirements. For the most up-to-date features and results, we encourage you to use HealthTracks

You can log into HealthTracks using the same credentials you use for AntechOnline. If you prefer MIC results to be emailed directly to your hospital’s email address, please contact HealthTracks support at [email protected] to have your email preferences updated.

Please note, fax reports are not yet available with these new features but will be in the near future

Customers that access their results within an integrated PIMS interface will continue to see MICs and S/I/R interpretations in the manner in which their PIMS chooses to show that data; however, PIMS views are dependent on the software company and new Antech-specific features are only available in HealthTracks.

If you prefer MIC results to be emailed directly to your hospital’s email address, please contact HealthTracks support at [email protected] to have your email preferences updated.

Please note: Fax reports are not yet available with these new features but will be in the near future