Medication Alerts

Horsemen are strongly urged to take notice of the following medication alerts: 


(Source: ARCI/RMTC)

Endogenous substances are substances that naturally occur in the horse. It is possible, however, to elevate the the normal physiological concentration of the substance in the horse via administration. There are various reasons why this is done, but none are considered appropriate. Indeed, the primary purpose is to affect the performance of the horse. The improper administration of some endogenous substances can threaten the health and welfare of the horse. The following endogenous substances are subject to regulatory control.


A blood specimen from a horse found to contain cobalt in excess of 25 nanograms per milliliter of blood plasma or serum shall be considered a positive finding. The Stewards and Judges shall be instructed to apply this regulation in the following manner:

1) A horse which tests for cobalt between 25 nanograms per milliliter of blood plasma or serum and 50 nanograms per milliliter of blood plasma or serum shall be placed on the vets list and not be permitted to start in a race until the horse tests for cobalt below 25 nanograms per milliliter of blood plasma or serum. All costs associated with any retesting shall be paid for by the owner of the horse.

2) A horse whose cobalt level exceeds 50 nanograms per milliliter of blood plasma or serum shall be disqualified, the trainer of the horse shall be suspended and/or fined at the discretion of the Stewards or Judges and assessed points under the multiple medication violation point system. As previously stated the horse shall be placed on the vets list and not permitted to start in a race until the horse tests for cobalt below 25 nanograms per milliliter of blood plasma or serum. All costs associated with retesting the horse shall be paid for by the owner of the horse.

Cobalt is considered a Class 3 substance under the ARCI Uniform Classification of Foreign Substances. Its Penalty Class is Class B.


GABA (gamma aminobutyric acid), a naturally occurring amino acid in the horse, has been identified as being administered, purportedly to calm a horse so that it remains calm through the paddock and into the post-parade on race day.  Often, GABA is administered as a part of a substance called “Carolina Gold”.  It is believed that this substance is often given at or around Lasix time. Improper administration of GABA can threaten the health and welfare of the horse. Accordingly, the administration of exogenous GABA to a horse is prohibited.

  • The GABA testing threshold in the horse may not exceed 110 nanograms per milliliter in plasma/blood.
  • GABA is considered a Class 3 substance under the ARCI Uniform Classification of Foreign Substances. Its Penalty Class is Class B.


The use of agents that elevate the horse’s TCO2 or base excess level above those existing naturally in the untreated horse at normal physiological concentrations is prohibited. The following levels also apply to blood-gas analysis:

The regulatory threshold for TCO2 is 37.0 millimoles per liter of plasma/serum or a base excess level of 10.0 millimoles, and;

The decision level to be used for the regulation of TCO2 is 37.0 millimoles per liter of plasma/serum plus the measurement uncertainty of the laboratory analyzing the sample, or a base excess level of 10.4 millimoles per liter of plasma/serum.


(Source: ARCI/RMTC)

The presence of two or more non-steroidal anti-inflammatory drugs—Flunixin (Banamine®), Ketoprofen (Ketofen®), Diclofenac (Surpass®), Firocoxib (Equioxx®) and Phenylbutazone (Butazolidin®)—in blood and/or urine constitutes an NSAID stacking violation. Only one NSAID can be present in a post-race test sample below established thresholds. If more than one NSAID is detected in a post-race sample above the established thresholds, it is considered stacking and is a medication violation subject to penalty. Horsemen are cautioned to use only one NSAID during the week the horse is entered to race. If an additional NSAID is to be used, it should be not be used within 7 days of the race and should not be used in combination with another NSAID. The primary thresholds for the five NSAIDs are: Diclofenac—5 nanograms per milliliter in plasma; Firocoxib—20 nangrams per milliliter in plasma; Flunixin—5 nanograms per milliliter in plasma; Ketoprofen—2 nanograms per milliliter in plasma; and Phenylbutazone—0.3 micrograms per milliliter in plasma.


(Source: Mid-Atlantic advisory)

Notwithstanding the ARCI recommendation, horsemen are strongly cautioned against the use of Depo-Medrol for a horse in training. A trainer who chooses to race a horse that has been treated with Depo-Medrol despite this warning should, at his/her expense, get the horse tested prior to entry to ensure that the horse will test below the regulatory limit, which is 100 picograms per milliliter of plasma or serum.


(Source: Mid-Atlantic advisory)

Only Procaine Penicillin administrations within 30 days of a race need be reported to the state racing commission. The surveillance requirement remains in effect. The commission or the racetrack, as the case may be, will provide a security guard for the horse at the owner/trainer’s expense. Please note that the testing threshold for Procaine Penicillin is 25 nanograms per milliliter in plasma regardless of the surveillance requirement, and this testing threshold will be enforced.


(Source: ARCI/RMTC)

  1. The possession or use of a drug, substance, or medication on association grounds that has not been approved by the appropriate federal agency (e.g., the United States Food and Drug Administration) for any use in (human or animal) is forbidden without prior permission of the commission or its designee.
  2. It is a violation of this regulation to possess, use, or distribute a compounded medication on association grounds if there is an FDA approved equivalent of that substance available for purchase. A difference in available formulations or concentrations does not alleviate the need to use FDA approved products.
  3. It is a violation of this regulation to possess, use, or distribute a compounded medication on association grounds made from bulk substances if an FDA-approved equivalent is available for purchase.
  4. Combining two or more substances with pharmacologic effect constitutes the development of a new drug. This may only be done in accordance with state and local laws and must contain FDA-approved medications, if available.
  5. Compounded veterinary drugs: Veterinary drugs shall be compounded in accordance with all applicable state and federal laws. Compounded medication shall be dispensed only by prescription issued by a licensed veterinarian to meet the medical needs of a specific horse and for use only in that specific horse.
  6. Labels on compounded veterinary drugs: All compounded medications must be labeled in accordance with section ARCI-011-020(D) Medical Labeling.
  7. Possession of an improperly labeled product by any person on association grounds is considered a violation of this section.


(Source: RMTC)

Horses can be inadvertently exposed to, or come in contact with, regulated substances that if detected in a post-race urine or blood test can result in significant penalties. The trainer responsibility rule requires that horsemen bear responsibility for the presence of unauthorized substances in a horse at the time of testing regardless of intent or the route of exposure.

The Racing Medication and Testing Consortium is offering guidance for horsemen in managing the horse’s environment to prevent contamination.

Details on preventing environmental contamination are available here.


Under regulations adopted by the Pennsylvania Horse Racing Commission, effective Jan. 1, 2017, all containers of medication must be properly labeled and prescribed, and they will be subject to testing. The PHRC Dec. 1 notified horsemen and private veterinarians of the impending rules. Any containers that aren’t labeled or those that aren’t verified after testing could result in penalties for trainers and dispensing vets, according to a memorandum. The new regulations, which outline rules for professional conduct of vets, are outlined in the PHRC memo.


(Source: RMTC)

Levamisole is commercially available as a dewormer for cattle, sheep, goats and pigs. It also has conventional off-label uses in horses as an immunostimulant and as a medication for treatment of Equine Protozoal Myelitis (EPM). Levamisole metabolizes in the horse to aminorex and possibly also pemoline, both of which are potent stimulants assigned a 1/A Classification in the Association of Racing Commissioners International Uniform Classification of Foreign Substances. The identification of either of these substances in a post-race sample is associated with a potential career-ending penalty. In consideration of its conventional use in horses, the Racing Medication and Testing Consortium contemplated an administration study to develop guidance on the use of levamisole and surveyed practicing veterinarians on their use of levamisole. Survey results included indications for use; route of administration (oral or injectable); dose (500 milligrams to 2,500 milligrams); and frequency and duration of treatment (3 days to unending). Given the prevalence of compounded levamisole products and that survey results established there is no commonly used treatment protocol, the RMTC determined an administration study would yield limited information. Therefore, the RMTC recommends that following withdrawal of the medication, levamisole-treated horses be subjected to testing prior to entry to verify that levamisole and its metabolites have been eliminated from the horse. Before submitting a sample for clearance testing it is advisable to consult the regulatory authority to make sure that your sample meets the laboratory’s requirements for matrix and volume.


(Source: RMTC)

Glaucine, which has recently been identified in a number of post-race samples, is marketed as an anti-tussive (cough suppressant) and can have hallucinogenic effects at very high doses. No glaucine-containing products are FDA-approved in the U.S. A Racing Medication and Testing Consortium Glaucine Task Force has reported that glaucine is not only present in some bulk shavings but is also available in injectable forms online. In shavings, it is a result of the presence of the tulip poplar tree, which contains a number of plant alkaloids—two of which are asimilobine and liriodenine. One or both of these alkaloids have been identified in all samples of shavings tested that are positive for glaucine. Due to glaucine’s presence in bedding, a horse could ingest shavings prior to a race that could potentially result in a laboratory finding. This potential for inadvertent exposure, as well as intentional exposure, indicates that the simple use of a screening limit alone would likely not be sufficient in controlling the substance. Therefore, the following testing recommendations have been issued for glaucine:

  • 500 picograms/milliliter interim screening limit;
  • Penalties: Above 500 picograms/milliliter and below 1 nanogram/milliliter—warning; above 1 nanogram/milliliter—Class B Penalty.



The New York State Gaming Commission March 24, 2017, issued rules for the labeling of prescription medication dispensed by a veterinary pharmacy. Dispensing medication on the grounds of New York racetracks without a prescription label that meets the certain criteria may be considered professional misconduct. The memo from New York State Equine Medical Director Dr. Scott Palmer is available here.


The Racing Medication and Testing Consortium has published guidance for horsemen on use of herbal products and homeopathic remedies. The RMTC said caution is necessary in regard to using such products or remedies in proximity to a race. The RMTC pamphlet is available here.


Recently, there have been several positive findings for low level detections of the anabolic steroids trenbolone and trendione in Australia. Trenbolone is considered an androgenic anabolic steroid (AAS) with several formulations having FDA approval for use in cattle. Trendione is a metabolite of trenbolone and an AAS. There are currently no FDA approved medications containing trendione. The Australian findings were reportedly linked to the administration of a recently introduced injectable altrenogest product. Altrenogest is a progesterone receptor agonist used to control estrus in fillies or maintenance of pregnancy in mares. It is marketed in the United States as an oral formulation known as Regu-Mate. Recently, the FDA released a communication to inform those handling altrenogest of potential human health concerns posed by exposure to the drug. That document can be found here. In 2014 the California Horse Racing Board issued an advisory after detecting trenbolone in a specific lot of Regu-Mate. That advisory can be found on the second page of this document. Since 2014, there have been no findings for trenbolone in California. This is true even though fillies and mares in California have continued to use altrenogest as reflected in post-race testing results. In 2015 the Canadian Pari-Mutuel Agency had a finding for trenbolone in a post-race urine sample. Subsequently, the CPMA’s laboratory performed an administration study of altrenogest on several horses. In that case, some of the horses administered altrenogest had findings of α-trenbolone in their urine at 24 hours post-administration. The laboratory did not detect trenbolone in any blood samples post-administration. The regulation of altrenogest is specific to each state. The RMTC recommends that altrenogest remain a non-violation in fillies and mares unless administered in contravention of the jurisdiction’s mandatory stand down or other restrictions. Altrenogest should be considered a Class 4/C substance in geldings, colts and horses. The ARCI currently lists altrenogest as a Class 4/C substance without exception based upon sex. Trainers should be aware that the use of altrenogest may pose a risk of a positive finding for trenbolone or trendione. Trainers are recommended to use caution when using altrenogest and consider saving samples from any altrenogest containers until all post-race tests from sampled horses have been completed.


The Racing Medication and Testing Consortium has received several inquiries regarding cannabidiol (CBD) and products purported to contain the active ingredient or substances related to it. Cannabidiol is a constituent of cannabis. It is derived from both the marijuana and industrial hemp plants. It is not the substance responsible for the psychoactive effects in humans. It is, however, believed to exert some anti-anxiety, anti-inflammatory, and analgesic effects in humans. It is available in many over-the-counter “nutritional supplements” and in one FDA-approved prescription drug that is used to control two specific types of childhood epilepsy. There currently is no withdrawal time recommendation. For details, please read the RMTC bulletin on cannabidiol


The Association of Racing Commissioners International in December 2019 adopted a model rule that prohibits the use of bisphosphonates in any horse younger than 4. Bisphosphonates must be FDA-approved, administered according to instructions, and used only used to treat navicular disease. Bisphosphonates are now listed as a Prohibited Practice by ARCI.


Scopolamine (also known as hyoscine) is conventionally used in human medicine for the prevention of motion sickness. It is available by prescription in tablet and transdermal patch formulations. It has also had limited use in conjunction with general anesthesia in reducing airway secretions. It is associated with side effects of dizziness, drowsiness, blurred vision, nausea and dry mouth. Scopolamine has limited historical use in equine veterinary medicine to relieve intestinal spasms in the treatment of gas colic. However, gastrointestinal side effects, potential toxicity and the development of safer, more effective medications have rendered its use as a therapeutic medication obsolete. Scopolamine is an alkaloid present in Jimsonweed, a member of the poisonous plant species, Datura. Jimsonweed infests crop fields throughout North America and around the world. The live plant is associated with a strong odor and bitter taste, and animals tend to avoid its consumption unless other feed sources are unavailable. Scopolamine has been detected in the blood and/or urine of animals having consumed hay containing Jimsonweed, as the odor and bitter taste dissipate during the hay curing process. Symptoms of scopolamine toxicity, as observed in horses having consumed Jimsonweed-contaminated hay, include dilated pupils and intestinal paralysis, and can persist for several days following ingestion. The Association of Racing Commissioners International Uniform Classification of Foreign Substances has assigned scopolamine a 4/C classification. The alphanumeric system categorizes substances by pharmacologic effect (1-5) and penalty designation (A-D). Class 1 substances represent the greatest threat to the integrity of competition; Class 5 substances the lowest threat. Class 4 drugs comprise primarily therapeutic medications routinely used in racehorses. They may influence performance, but generally have a more limited ability to do so, according to ARCI, The alphabetical classifications include consideration of the pharmacologic classification (1-5) and additional factors such as the indications for medication use, potential for misapplication, and FDA-approval status. Class A is associated with the most severe penalties, whereas Class D is associated with lesser penalty recommendations. The ARCI recommended penalties for a first time 4/C violation include a minimum fine of $1,000 (absent mitigating circumstances). In consideration of the facts of the case, the horse may be disqualified. Scopolamine is on the United States Anti-Doping Agency’s list of permitted medications.


The Racing Medication and Testing Consortium has issued the following advisory on intra-articular and corticosteroid injections. It establishes a 14-day stand-down period following an intra-articular injection and prohibits the “stacking”—use of more than one—corticosteroid. The advisory is available here.


Harpagoside is a glycoside derived from the Devil’s Claw plant (Harpagophytum procumbens). It is a non-steroidal anti-inflammatory drug that inhibits COX-1 and COX-2, similar to phenylbutazone. There are no FDA-approved harpagoside-containing products. To the extent that Devil’s Claw products exist, they are manufactured absent regulatory oversight—with unknown safety, efficacy, stability, and purity. Harpagoside is assigned a 4/B classification in the Association of Racing Commissioners International Uniform Classification of Foreign Substances, consistent with other NSAIDs lacking FDA approval. The detection of harpagoside in a post-race sample can result in a horse’s disqualification, a fine, and suspension for the trainer. Devil’s Claw products are marketed in a variety of over-the-counter formulations as herbal remedies for a range of conditions including arthritis, fever, and muscular pain. Harpagoside content can be highly variable from one product to the next, as well as from batch to batch for a single product. Additionally, the amount of harpagoside may differ substantially from that declared on the label contents. For these reasons, there is no reliable withdrawal guidance for the use of these products. Further, labels may not clearly indicate the presence of harpagoside or Devil’s Claw but simply refer to a “proprietary blend of herbs” so the end-user may be unaware that the product contains a prohibited substance. The Devil’s Claw plant is indigenous to southern Africa, growing in dry sandy soil; it is not native to North America and is not a constituent of bedding, forage or hay. Therefore, the introduction of Devil’s Claw, or its derivatives, into a horse’s environment can be prevented by common sense hygiene practices and stable management. Horsemen are advised to exercise caution in using these products in proximity to a race. Should a veterinarian determine harpagoside treatment is warranted for a specific patient, clearance testing is recommended.


Effective immediately, horsemen are urged to discontinue the use of any and all adjunct bleeder medications for horses in training, including in particular, aminocaproic acid–commonly called Amicar.

Amicar and several other adjunct bleeder medications were placed on the Prohibited List in 2013 under the Association of Racing Commissioners International Uniform Classification Guidelines for Foreign Substances and Recommended Penalties Model Code and the National Uniform Medication Program. Aminocaproic acid, for example is a Class 4 substance and penalty Class C.

It is important to understand that these medications cannot be regulated by withdrawal time guidance and/or a testing threshold and their use, no matter how far in advance of a race, may trigger a positive post-race test.

Any trainer who chooses to continue the use of these medications for training in the future will run the risk of a post-race positive test.


Thyroid supplementation is prohibited, and trainers may not have thyroid supplements in their premises on the racetrack or training centers, nor may they administer such supplements, unless the following conditions are met:

  • The horse has been diagnosed with hypothyroidism pursuant to a thyroid releasing hormone stimulation test (TRH). A T3 or T4 test without stimulation of the thyroid is insufficient to diagnose hypothyroidism.
  • The results of the TRH stimulation test must be submitted to Dr. Libby Daniel, the MRC Equine Medical Director.
  • If approved by the Equine Medical Director, the horse may be treated with only Federal Drug Administration-approved medications for hypothyroidism prescribed by a veterinarian. Possession of any thyroid supplements that are not pursuant to a veterinary prescription under this directive is prohibited and will result in strict disciplinary action.
  • If a horse is currently being administered a thyroid supplement, administration of the supplement should be discontinued and a TRH test conducted after a 30-day washout period.