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Xylocaine (lidocaine) withdrawal and detection times for horses

Xylocaine (lidocaine) is a local anaesthetic, also sold as Lignocaine, Xylocaine. Below: how 10 show and racing governing bodies list it, every published detection time for the dose and route studied, and the document and page each value comes from.USEF: Permitted with conditionsFEI: Controlled Medication, detection time 48 h (2 days)HISA/HIWU: detection time 48 h (2 days)named in the rules of 20 state racing commissions

Published detection times for Xylocaine

Each row is one study the governing body published: its own dose, route and formulation. A different dose or route was not studied, and the body says so.

Body and documentDose and route studiedFormulationHorsesDetection time
USEF (US Equestrian)
2026 (last revised 1 Dec 2025; amendments effect… p. 11
dose not stated in the row168 h (7 days)
plasma / urine
FEI
2024 (16 December 2024) p. 2
60-300 mg · sq648 h (2 days)
HISA / HIWU
Last updated on December 8th, 2023 p. 18
200 mg of lidocaine as its hydrochloride salt administered subcutaneously · sq648 h (2 days)
plasma / urine
HISA / HIWU
080624 p. 4
200 mg of lidocaine, as lidocaine hydrochloride, administered subcutaneously · sqlidocaine hydrochloride648 h (2 days)
plasma / urine
IFHA / EHSLC
Undated PDF p. 2
300mg/15mL, single dose · sqNorocaine® Norbrook Laboratories672 h (3 days)
urine
IFHA / EHSLC
Undated PDF p. 2
60mg/3mL, single dose · sqNorocaine® Norbrook Laboratories672 h (3 days)
urine
RMTC (advisory)
Updated September 30, 2024 p. 4
200 mg of Lidocaine, as Lidocaine Hydrochloride, administered subcutaneously · sqLidocaine HCL 2%648 h (2 days)

Advisory withdrawal guidance (RMTC)

The Racing Medication and Testing Consortium publishes withdrawal guidance built on HISA's detection times. It is advisory, not a rule, and ShowSafe Pro shows it beside the HISA result, never in place of it.

Dose and routeWithdrawal guidanceHISA detection timeSource
200 mg of Lidocaine, as Lidocaine Hydrochloride, administered subcutaneously · sq72 h (3 days)RMTC advisory p. 4
72 h (3 days)RMTC advisory p. 4

How each rulebook lists Xylocaine

Transcribed from the governing bodies' own documents. Each entry links to the document and quotes the row it came from.

USEF (US Equestrian)

2026 USEF Guidelines & Rules for Drugs and Medications (with 27 Jul 2026 Guidelines Update) p. 9 · 2026 (last revised 1 Dec 2025; amendments effective 27 Jul 2026, published 10 Aug 2026)
Permitted with conditions
  • Listed as: Potentially Permitted with Medication Report Form (MRF) according to GR411 · Timing: not within 24 h (1 day) of competition · Medication report form: required
  • Listed as: How Long Drugs Remain Detectable · Detection time: 168 h (7 days) for the dose studied · Medication report form: required
“Potentially Permitted with Medication Report Form (MRF) according to GR411: ... lidocaine” — source p. 9

FEI

2026 Equine Prohibited Substances List p. 21 · 2026 (effective 1 January 2026)
Controlled medication
  • Listed as: Controlled Medication
“CONTROLLED Lidocaine Local anaesthetic” — source p. 21
FEI List of Detection Times p. 2 · 2024 (16 December 2024)
Controlled medication
  • Listed as: Controlled Medication · Detection time: 48 h (2 days) for 60-300 mg · Routes: sq
“LIDOCAINE2 60-300 mg s.c. 6 48 (2d)” — source p. 2

From 2027-01-01: 2027 Equine Prohibited Substances List p. 22 lists it as Controlled Medication.

Equestrian Canada

Controlled medication
  • Listed as: Prohibited substance
“Lidocaine” — source p. 11

AQHA

Permitted with conditions
  • Listed as: Quantitatively Restricted Therapeutic Medication (VIO405) · Medication report form: required
“VIO405.11 Lidocaine/Mepivicaine - This medication may only be used under actual observation of event management” — source p. 48

APHA

Permitted with conditions
  • Listed as: Permitted Therapeutic Substance (SC-085.A) · Medication report form: required
“12. Lidocaine/Mepivacaine ... a. When administered within 24 hours of showing, may only” — source p. 79

NRHA

NRHA Medications Database · Database reflecting Board-approved changes effective 1 Jan 2026 (retrieved 3 Oct 2026)
Permitted with conditions
  • Listed as: Conditionally Permitted · Timing: not within 24 h (1 day) of competition · Medication report form: required
“Lidocaine ... Conditionally Permitted ... Conditionally permitted substances require a 24-hour withdrawal prior to the horse competing.” — source

NCHA

2026 NCHA Rule Book - Standing Rule 35A, Medication and Drug Rules and Guidelines p. 5 · 2026 Rule Book, SR 35A extract (pages 75-95; PDF created 30 Jun 2026)
Permitted with conditions
  • Listed as: Conditionally permitted local anesthetic (35A.8.b.iv) · Timing: not within 24 h (1 day) of competition · Medication report form: required
“Local anesthetics, which are RAC class 2 substances and are considered prohibited substances unless the horse” — source p. 5

HISA / HIWU

Controlled medication
  • Listed as: Controlled Medication Substance · Screening limit: 10 ng/mL as 3-hydroxylidocaine in urine or 0.02 ng/mL as 3-hydroxylidocaine in serum or plasma · Detection time: 48 h (2 days) for 200 mg of lidocaine, as lidocaine hydrochloride, administered subcutaneously · Routes: sq
“Lidocaine ... 200 mg of lidocaine, as lidocaine hydrochloride, administered subcutaneously ... 48 hours (6) ... 10 ng/mL as 3-hydroxylidocaine in” — source p. 4
HISA Prohibited Substances List: Controlled Medications p. 18 · Last updated on December 8th, 2023
Controlled medication
  • Listed as: S7 Controlled Medication Substances · Screening limit: 10 ng/mL as 3-hydroxylidocaine in urine; 0.02 ng/mL as 3-hydroxylidocaine in serum or plasma · Detection time: 48 h (2 days) for 200 mg of lidocaine as its hydrochloride salt administered subcutaneously · Routes: sq
“Lidocaine ... 48 hours: 200 mg of lidocaine as its hydrochloride salt administered subcutaneously (6 horses) ... 10 ng/mL as 3-hydroxylidocaine in urine; 0.02 ng/mL as” — source p. 18

ARCI

Controlled medication
  • Listed as: Class 2, Penalty B
“Lidocaine Xylocaine 2 B” — source p. 35
ARCI Controlled Therapeutic Medication Schedule for Horses p. 4 · Version 4.2.1 (Revised December 2020); policies from Model Rules Version 15 (August 2026)
Permitted up to a threshold
  • Listed as: Controlled Therapeutic Medication · Dose in the rule: 200 milligrams of lidocaine as its hydrochloride salt administered subcutaneously · Screening limit: 20 picograms per milliliter of total 30H- lidocaine in plasma or serum · Routes: sq
“Lidocaine | 20 picograms per milliliter of total 30H- lidocaine in plasma or serum | 72 hours” — source p. 4

IFHA / EHSLC

Controlled medication
  • Listed as: Legitimate therapeutic substance controlled by International Screening Limit · Detection time: 72 h (3 days) for 300mg/15mL, single dose · Routes: sq
  • Listed as: Legitimate therapeutic substance controlled by International Screening Limit · Detection time: 72 h (3 days) for 60mg/3mL, single dose · Routes: sq
“Lidocaine Norocaine® Norbrook Laboratories 300mg/15mL, single dose s/c (6) 72” — source p. 2

State racing commissions

Xylocaine is named in the medication rules, threshold schedules or withdrawal guidance of 20 state racing commissions: Arizona, California, Colorado, Florida, Illinois, Indiana, Kentucky, Louisiana, Maine, Maryland, Minnesota, Nebraska, New York, Ohio, Oklahoma, Oregon, Pennsylvania, Texas, Washington, West Virginia. Most states publish thresholds (concentrations), not times, and several adopt the ARCI schedule by reference. ShowSafe Pro Racing layers each state's rules over HISA or ARCI the way that state applies them, for all 32 states with live pari-mutuel racing.

Detection time is not withdrawal time

A published detection time tells you how long Xylocaine stayed detectable in a handful of horses given one dose by one route. It does not tell you when your horse is clear: a bigger dose, a different route, repeated doses, a joint injection or a slower horse all push the real figure out, and every governing body says to add a safety margin set by your veterinarian. Here is how to read the rulebook.

ShowSafe Pro takes the doses already logged for your horse, matches each one to the published row for that dose and route, adds the margin your vet set, and flags anything the studies never covered as Unknown, ask your vet instead of guessing. Every answer shows the document, page and line it came from, for every rulebook the show runs under.

A detection time is the approximate period a drug or its metabolite stayed detectable in the horses studied, at the dose and route studied. It is not a withdrawal time. No governing body publishes withdrawal times for you; your veterinarian sets the safety margin for your horse. Nothing on this page is a veterinary ruling or a promise that a horse will test clean. Rules change; the document, version and page behind every value are linked so you can check the current text.

Questions about Xylocaine

Is Xylocaine allowed at USEF shows?

The 2026 USEF Guidelines & Rules for Drugs and Medications (with 27 Jul 2026 Guidelines Update) list Xylocaine as "Potentially Permitted with Medication Report Form (MRF) according to GR411". Not within 24 h (1 day) of competition. (Page 9.)

What is the FEI detection time for Xylocaine?

The FEI List of Detection Times gives 48 h (2 days) for 60-300 mg sq. On the 2026 FEI Equine Prohibited Substances List Xylocaine is a Controlled Medication. The FEI states that a detection time is not a withdrawal time; the treating veterinarian adds a safety margin.

How long before a race can a horse have Xylocaine under HISA?

HIWU's published detection time for Xylocaine is 48 h (2 days) for 200 mg of lidocaine as its hydrochloride salt administered subcutaneously (6 horses), screening limit 10 ng/mL as 3-hydroxylidocaine in urine; 0.02 ng/mL as 3-hydroxylidocaine in serum or plasma. RMTC's advisory withdrawal guidance for the same dose is 72 h (3 days). A detection time is not a withdrawal time; HISA leaves the safety margin to your veterinarian.

Does a published detection time mean my horse will test clean?

No. It is the approximate time Xylocaine stayed detectable in the horses studied, at that dose and route. Your horse, dose, route and number of doses may differ. Every governing body tells you to add a safety margin set by your veterinarian, and none publishes a withdrawal time. ShowSafe Pro applies the published row for the dose and route you actually gave, adds your vet's margin, and says 'Unknown' when the studies do not cover what you gave.

Other local anaesthetic medications

Carbocaine (mepivacaine)

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