Equine Sports Council

Controlled Medications Library

ESC MEDICATION CLASSIFICATIONClass A - Therapeutic

ESC Medication Library · Revision 3

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Acetylsalicylic acid,

Medication Facts

Performance enhancing
No
Total hours to clear
Not recorded
Frequently used
Most Prescribed
ESC ID
ACETYL-0023
Trade names
Bayer Aspirin
Drug type
NSAID, Cox2 Inhibitor
Plasma half-life · hours
0.11 to 0.53
Equine dosing
10-15 mg/kg PO
Cmax · peak plasma concentration
300 µg/mL
Tmax · time to peak plasma concentration
3
ESC concentration guidance
300 mg/mL
Primary withdrawal · hours
0
Washout withdrawal · hours
0
ESC control type
A1 - Generally Controlled - Therapeutic
Medication report required
Generally not required, however understand exceptions.

Uses & side effects

Inhibits COX Production (COX inceptors cause inflamation/fever)

Drug interactions

Using more than one NSAID concurrently (e.g., combining phenylbutazone, flunixin meglumine, or firocoxib) drastically increases risks of toxicity without increasing pain relief.Corticosteroids (e.g., Dexamethasone): Combining NSAIDs with steroids increases the likelihood of gastric ulcers and severe GI toxicity.Nephrotoxic Agents: Avoid combining NSAIDs with aminoglycoside antibiotics (e.g., gentamicin) or diuretics, as this significantly increases the risk of acute renal failure.Blood Thinners: Concomitant use with anticoagulants (e.g., heparin) increases the risk of bleeding complications.Dehydration/Pre-existing Disease: NSAIDs are more toxic when horses are dehydrated, septic, or have pre-existing kidney or hepatic disease

Contraindications

None currently identified.

Government Numbers

Bayer Genuine Aspirin 325 mg: human OTC product; monograph M013. This repackaged presentation uses NDC 85237-1828-0 (2-tablet pouch); source NDC 0280-2000. Labeler: Select Consumer Group. These identifiers do not establish equine approval or an equine dose. Label updated July 3, 2026; reviewed September 18, 2026. https://www.dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=3ca776c2-47ed-5107-e063-6394a90ac5df

Sanctioning-body comparison

Plasma only. Compare published competition guidance for this medication. ESC guidance remains in Medication Facts above. A dosing guideline, withdrawal recommendation and laboratory detection threshold are different measures.

Sources reviewed September 23, 2026. “Not verified” means a gap in this comparison, not zero tolerance or permission. Doses describe the cited rules; your veterinarian must determine treatment and withdrawal.

Published guidance by organization
OrganizationPublished dose & routePlasma concentrationWithdrawal / timingControl / penalty class
AQHA Show HorsesShow rules · 2026 handbook
Conditions & sources

An unverified entry is not permission to use this medication. Consult the linked current rules.

Reviewed 2026-09-23

Not verified for this medication.Not verified for this medication.Not verified for this medication.Medication-specific control not yet verified.
APHA Paint Show HorsesShow rules · 2026 Rule Book
Conditions & sources

An unverified entry is not permission to use this medication. Consult the linked current rules.

Reviewed 2026-09-23

Not verified for this medication.Not verified for this medication.Not verified for this medication.Medication-specific control not yet verified.
ARCI Model RulesRacing model · Rules 15 / UCG 20.0 / CTMS 4.2.1
Conditions & sources

An unverified entry is not permission to use this medication. Consult the linked current rules. ARCI model comparison only; no state-specific rule is substituted. Schedule timing is tied to its stated regimen and is not a clearance guarantee.

UCG 20.0 PDF p. 11

Reviewed 2026-09-23

Not verified for this medication.Not verified for this medication.Not verified for this medication.Drug Class 4 · Penalty Class C. No dosing permission is implied by classification.
USEFNational Therapeutic Substance Provisions · 2026 + July amendment
Conditions & sources

An unverified entry is not permission to use this medication. Consult the linked current rules.

Reviewed 2026-09-23

Not verified for this medication.Not verified for this medication.Not verified for this medication.Medication-specific control not yet verified.