Common Drugs - Their Uses AQHA & USEF Hotline #

Equine Drugs & Medications
Presented by Kathy Ott, DVM – Cleary Lake Veterinary Hospital
December 13, 2010

please note date -  rules may have changes


A) Commonly Used Drugs

1) Anti-inflammatories (NSAIDs)
2) Antibiotics
3) Sedatives
4) Steroids

    • Therapeutic
    • Hormonal

5) Muscle Relaxants
6) Antihistamines
7) Blocking Agents
8) Reproductive Drugs
9) Anti-ulcer Drugs
10) Eye medications
11) Dewormers
12) Topicals
13) Diuretics
14) Miscellaneous

B) Properly Giving Medications

C) Show Regulations & Guidelines

  •  USEF
  •  AQHA

D) Race Drugs

E) Generic Drugs

F) Compounded Drugs


A) Commonly Used Drugs 

1. Non-steroidal Anti-inflammatories (NSAIDS)

  • Reduce inflammation (decreases swelling), control pain (analgesic) and reduce fever (Anti-pyretic)
  • Excessive use can cause gastric or intestinal ulcers and/or kidney or liver damage and reduce clotting ability.
  • *Always take temperature (99-101) of horse first and confer with veterinarian prior to giving.

Phenylbutazone (bute)

  • Comes in pills, paste, powder or injectable
  • Injectable can only be given in the vein, NOT in muscle; it will cause severe muscle damage. If it leaks outside the vein it can cause severe phlebitis or thrombosis of jugular vein.
  • Most likely of the NSAIDs to cause ulcers from high doses or long-term use.

Flunixin meglumine (Banamine®)

  • Available in paste or injectable form
  • Good drug for colic and muscle pain
  • Allow 30 – 40 minutes to take effect
  • Intramuscular injections of Banamine can cause severe or fatal clostridial myositis and are not recommended.
  • IV injections can accidentally be given intra-arterially (carotid artery) and cause seizures, collapse and death.

Ketoprofen (Ketofen®)

  • Shorter half-life than above drugs so less damaging but also shorter time it’s effective.
  • Can be “stacked” with above drugs for USEF showing if proper documentation filed (until December 2011).
  • Labeled IV only but given IM as well.
  • Many drugs sound and “look” alike though can be greatly different uses and actions.

Firocoxib (Equioxx®)

  • Newer drug with fewer GI side effects (was Vioxx®)
  • Available in paste or injectable (IV) forms
  • More expensive than above drugs.

Acetylsalicylic acid (Aspirin)

  • Has a very short half-life in horses
  • Primarily used for eye problems such as uveitis (moon blindness). 
  • Comes in powder form and is given orally twice daily.

Dipyrone (Novin®)

  • Antipyretic, antispasmotic used for colic
  • Forbidden for USEF showing.

Naproxen (Naprosyn®; Aleve® in humans)

Meclofenamic acid (Arquel®) – no longer available

Surpass® (Diclofenac) – see under topical

  • Has limitations on amount used.

DMSO (dimethyl sulfoxide - Domoso®)

  • Used topically, IV or orally via stomach tube
  • Used for central nervous system problems, founder, swelling and inflammation.

“Natural anti-inflammatories”

  • These are “drugs” too and in high doses may have side effects.
  • Includes devils claw, yucca, grape seed extract.

2. Antibiotics
Used to treat infections; best prescribed based on culture and sensitivity
as a lot of resistance occurs.
GI upset and diarrhea are the most common side effects.
Frequency of administration varies greatly between antibiotics.
TMS, SMZ, Tucoprim®, Uniprim® (sulfas)
Most commonly used antibiotics; most resistance as well.
Inexpensive with little side effects.
Acts as an anti-inflammatory as well as an antibiotic
Used for tick-borne diseases and susceptible infections
Very bitter taste, often given rectally or will cause anorexia
Used for anaerobic infections
Procaine Penicillin
Gram-positive coverage, lots of resistance developing; given IM
Can cause anaphylactic reaction or procaine reaction – we recommend
against its use unless prescribed by a veterinarian.
Prohibited USEF or AQHA showing due to Procaine
Available over the counter; recommend not purchasing (storage
Potassium penicillin can be given IV but is very expensive and reactions
can still occur
Gram negative coverage; given IV or IM. Can sting when given.
Ceftiofur (Naxcel®)
Given IM. Expensive, but few side effects.
Good broad-spectrum coverage, especially gram-positives.


Given IV for Lyme, Anaplasmosis, etc.
Enrofloxacin (Baytril®)
Given IV or orally. Expensive. DO NOT use in foals.
Oral powder – available compounded.
Ponazuril (Marquis®)
Treatment for EPM – 28-day course of oral paste
Diclazuril (Protozil®)
Brand-new EPM treatment – oral granules

3. Sedatives/Tranquilizers
Most common. Available in paste or injectable (IM or IV).
Best for sheath cleans (penile paralysis?)
Not a pain killer, very slow onset.
Decreases seizure threshold; be careful in cushingoid/older horses.
Lowers blood pressure (vasodilates); don’t use if bleeding.
Orally: takes 2 hours to work; IM: takes 45 minutes; IV: takes 10-15
Detomidine (Dormosedan®)
Available in injectable (IM or IV) or gel (given under tongue)
Fast acting, good pain killer, causes significant ataxia
Xylazine (Rompun)
Available in injectable (IM or IV), can be mixed with ace
Good pain killer; used in refractory colic cases, causes ataxia
Romifidine (Sedivet®)
Same class as detomidine and xylazine
Causes sedation without as much ataxia
Butorphanol (Torbugesic®, Dolorex®)
Opioid – controlled substance, good pain killer
Can cause excitement if given alone
Generally given with xylazine or detomidine
Oral or injectable; tests for 30 days
Injectable can cause severe diarrhea
Is actually a human antipsychotic drug
Used for horses on stall rest (pills are best – can titrate dose)
Injectable human anti-psychotic medication
Dangerous; severe side effects can occur. Used some at racetracks.
Other quieting agents
Dexamethazone, Valerian root, Magnesium Sulfate, B-1, ACTH


4. Steriods
Therapeutic – Corticosteroids (“cortisone”)
Most commonly used for allergies (heaves, hives, etc), anaphylactic
reactions, severe inflammation, spinal or brain trauma.
Has mild quieting effect
Comes as injectable (IM or IV) or powder
Powder is compounded and has short expiration.
Injectable as 2mg/mL or 4mg/mL (3mg/mL active ingredient)
Triamcinolone (Vetalog®, Kenalog®)
Longer acting; used primarily in joints; protective effect on cartilage
Methylprednisolone (Depo-Medrol®)
Used primarily in joints; can cause cartilage damage in long term
Don’t confuse with Depo-Provera/P-4
Prednisolone (Solu-Delta Cortef®)
Fast acting! Solu-Delta Cortef is injectable.
Oral prednisone is not absorbed by horses; needs to be prednisolone
(available in tablets)
Hormonal (DO not handle if pregnant)
Altrenogest/Progesterone (Regu-Mate®)
Oral use; regulates mare’s cycles, keep mares out of heat
“Legal” for mares (USEF) but not geldings or stallions; not tested for.
P-4 (Depo-Provera®/“Depo”; injectable progesterone)
Can cause muscle soreness.
New injectable progesterone
More expensive than Regu-Mate.
From BETS lab – has 2 new compounded injectable altrenogests: 10 day
& 30 day
Synovex® implants
Combination of progesterone and estrogen
Used to suppress estrus (heat)
ECP (estrogen/estradiol)
Used for “locking stifles”
Boldenone (Equipoise®)
Muscle builder & appetite stimulant
Formerly used at the racetrack; potential for abuse
Stanazolol (Winstrol®) & Testosterone
Other anabolic steroids with potential for abuse


5. Muscle relaxants
Methocarbamol (Robaxin®)
Available only in tablet form now (500mg or 750mg)
OK to use USEF in regulated doses (i.e. 10 500mg tabs, 6.5 750mg tabs)
Compounded forms available in paste or injectable
Useful in treatment/management of exertional rhabdomyolysis (tying up)
Illegal USEF, AQHA
Given IV; compounded only; questionable efficacy; not tested for
“Natural” oral supplement for tie-up horses

6. Anti-Ulcer drugs
Omeprazole (GastroGard®, UlcerGard®)
FDA approved
Note: Compounded omeprazole (there is no generic for horses) and the
human form Prilosec® are available but are not FDA-approved and do not
have the same absorption and bioavailability as GastroGard and
UlcerGard. GastroGard and UlcerGard are microencapsulated and survive
the stomach acid to be absorbed in the duodenum.
Used in gastric hind gut ulcers. Questionable availability.
Not proven effective in gastric ulcers in horses; used more as anti-tumor
medicine for melanomas
Oral supplements
U-7®, Neigh-Lox®, Ulcrin®
Make many claims but no peer-reviewed research to support them

7. Antihistamines
Used for allergies or allergic reactions; illegal for USEF & AQHA
Human drug; good for hives; comes in tablets/pills
Pseudoephedrine/Pyrilamine (Tri-Hist Granules™)
Equine powder; questionable efficacy; granules
Injectable antihistamines
VERY dangerous in the horse i.e. Tripelennamine (Recovr®)

8. Blocking Agents
Illegal USEF or AQHA – can be with held 24 hours and medication form
filled out by veterinarian if used for a therapeutic purpose.
Most commonly used to block for sutures, etc.
Longer acting & less irritating than lidocaine
Used for nerve blocks and joint blocks
Pitcher Plant Extract (Sarapin®)
“Natural” blocking substance; illegal but not tested for
Benzocaine (EPF-5®/Equine Pain Formula)
Capsaicin (Equiblock®)
Illegal venoms – cobra venom; cone snail venom
No legitimate therapeutic uses; can cause sloughing of skin.

9. Reproductive Drugs (DO NOT handle if pregnant)
Altrenogest (Regu-Mate®)
Oral – Keeps non-pregnant mares out of heat and keeps pregnant mares
Prostaglandins (Lutalyse®, Prostin®)
Brings mares into heat
IM injection only; can cause severe sweating and cramping 15 minutes
after administration
Helps with milk let-down and to clear uterus; causes cramping
Do NOT give to pregnant mares
HCG – human chorionic gonadotropin (Chorulon®)
Induces ovulation
Induces ovulation
Helps with milk production/let-down in mares not producing enough


10. Eye Medications
Tubes of medicine look very similar!!
Consult a veterinarian first and check expiration dates!
Antibiotic ointments/drops
Triple Antibiotic: Neomycin/Polymyxin B/Bacitracin
Gentamicin, chloramphenicol, ciprofloxacin, oxytetracycline
Used for treatment of corneal ulcers and conjunctivitis
Steroid ointments/drops
Hydrocortisone and dexamethasone; usually combined with an antibiotic
Dangerous to use if eye is injured
Used for uveitis or conjunctivitis
Atropine ointment/drops
Dilates the eye – use sun protection!
Relieves pain associated with constricted pupil
Can cause ileus (reduced gut motility) and colic with long-term use
Horse’s own serum, spun down from whole blood
Healing growth factors and anti-inflammatory proteins help heal ulcers
Antifungal drops

11. Joint Support Medications
Polysulfated glycosaminoglycans – PSGAGs (Adequan®)
Given IM for joints, tendons, ligaments
Can also be given intra-articularly, usually in combination with a
Hyaluronic acid (Legend®, Hyalovet®, Hyvisc®, Hylartin V®)
Legend is given IV, primarily for joints
Other forms used intra-articularly, usually in combination with a
Some forms derived from rooster combs; others are laboratory-generated
Compounded, unknown efficacy
Component of cartilage/synovium
Oral Joint Supplements (“neutraceuticals”)
Hundreds of products available; none are FDA-approved
Components can include glucosamine, chondroitin sulfates, MSM,
avocado soy unsaponafiables (ASU), hyaluronic acid, hydrolyzed
collagen, vitamin C, herbal ingredients, etc.
Our top choices are: Platinum CJ, Cosequin ASU, SmartFlex products


12. Diuretics
Diuretic used to control HYPP in quarter horses and paints; also used for
Furosemide (Lasix®, Salix®)
Used to treat severe edema and congestive heart failure
Given to racehorses pre-race to reduce risk of exercise-induced
pulmonary hemorrhage (EIPH – “bleeding”); also in barrel horses
Trichlomethiazide/Dexamethasone (“Tri-dex”/Naquasone®)
Used to control limb edema/inflammation

13. Miscellaneous Drugs
Clenbuterol (Ventipulmin®)
Bronchodilator; illegal for showing
Useful in serve cases of recurrent airway obstruction (heaves) or
inflammatory airway disease
Pergolide (formerly Permax®)
Only available compounded; used to treat Cushing’s diseas
Supplemental thyroid hormone for metabolically challenged horses
Tiludronate (Tildren®)
Anti-osteoclastic drug; keeps bone from self-destructing
Useful in true navicular disease and other cystic diseases (stifle OCDs)
Very expensive – have to order from overseas
Vasodilator; used to increase blood flow to feet
Currently only available compounded. OK for USEF.
Vitamin B12 (Cyanocobalamin)
Appetite stimulant, “upper”

14. Topicals
Antibiotics/antibacterials/wound treatments
Nitrofurazone (yellow ointment) – many trade names. Use gloves! Also
good for sweat wraps.
Chlorhexadine - Dermachlor®, Nolvasan®; Good topical antibiotic.
Scarlet oil/BluKote® – Very irritating
Caustic powder/ WonderDust® – proud flesh control
Gentamicin/betamethasone spray – antibiotic & anti-inflammatory
AluSpray® (aluminum): “liquid bandage”
SWAT – bug repellent built in
Sunscreen – good for white noses
Zinc oxide – sunscreen/soother on irritated skin
Iodine – best for use in feet
Thrush treatment – Kopertox (copper naphthenate), Thrush Buster,
bleach, iodine, dry cow treatment (Tomorrow® - cephapirin antibiotic)
Pain control/anti-inflammatory
Surpass®, DMSO, EquiBlock®, EPF-5®

15. Dewormers
Look for chemical names (active ingredient!)
Note: Brand names can cause confusion – e.g. Zimectrin® is the same as
Parid Eq® (both are ivermectin); Equimax® is the same as Zimectrin
Gold® (both are ivermectin and praziquantel)
Basic Dewormers by chemical:
Avermectin class: ivermectins (see above), moxidectin (Quest®)
Pyrantel class: Strongid®, Strongid C®
Benzimidazoles: fenbendazole (Panacur®), oxibendazole (Anthelcide EQ®)
Praziquantel: Added for tapeworms

B) Properly Giving Medications How to give medications
Always take temperature first!
Check expiration date
Call veterinarian!
Prescription medications: Veterinarians must have a proper client/patient
relationship and have seen horses with in the last 12 months in order to
dispense medications. State Law!
Always continue medications for full treatment recommendation and stay on
schedule (especially important for antibiotics)
Notify veterinarian if horse is not tolerating treatment or if there are any
problems administering the medication as directed.
Oral medications – pills, powder, paste
Pills/powder – can give in feed
- Can crush or grind in coffee grinder
- Some can dissolve in syringe and give in mouth as paste
Pastes – check that the tab is set prior to administration (e.g. one client gave
an entire tube of wormer to a miniature horse, and another client gave an
entire tube of bute paste to pony)
New Dormosedan gel – Goes UNDER the tongue (sublingual)
Double-check dosages
Check with your veterinarian about placing medications in feed, or additives
that may make administration easier, such as molasses, karo syrup, apple
sauce, or sugar-free maple syrup for insulin-resistant horses.
Always use a new needle and sterile syringe.
Intravenous (IV) injections should only be given by trained personnel:
dangers include hitting the carotid artery (causes seizures, violent reactions
and occasionally death) or injecting subcutaneously, causing local irritation
Intramuscular (IM) injections can be given in neck, hind leg
(semimembranosus) or pectorals (not the gluteals!). Beware of bacterial
infections possible with any IM injection.
Subcutaneous (SQ) injections – allergy injections only
Eye medications
Do not touch eye with the tip or applicator; hold it off to side
Can use a tuberculin syringe under the eyelid
Don’t need to place medication directly over the injury – the eye will spread
out the medication effectively
Wait 5 minutes between eye medications

C) Show Regulations & Guidelines note check date for rule changes

USEF & AQHA call #1-800-MED-AHSA(633-2472) hotline
IV or IM, used for therapeutic purposes only
2mg/100lb > 12 hours = 1200lb = 24 mg. (1200lb = 12ml of 2mg/ml)
Note: 4mg/mL Dex is actually 3mg/mL active ingredient, so for a 1200-
lb. horse you need to actually give 8mLs, not 6mLs.
Can be used in combination with an NSAID.
Use no more than 5 days in a row.
Other Steroids
Triamcinolone (Vetalog), methylprednisolone (Depo-Medrol)
If given for therapeutic use, less than 7 days prior to competition
Must fill out drug report (i.e. injecting joints).

NSAIDS – (See list above)

  • Dexamethasone and Methocarbamol are not NSAIDs and can be used in conjunction with any one of the NSAIDs.

NEW RULES: note date as of 2010 - new rules may apply

  • If using more than one NSAID within 7 days, you must file an NSAID medication report. As of December 1, 2011, you can no longer use 2 NSAIDs within 7 days. (Note: this may change to 3 days).
  • Also new rule change proposed to allow Banamine for colic. This would have a 24-hour withdrawal and file medication report.


  • cannot be used within 7 days


  • can now be used anytime with no report


  • can be given at anytime with no report

Regu-Mate & injectible progestins 

  • not actually “legal” for geldings and stallions, but not forbidden substances either.

Magnesium sulfate (MgSO4) 

  • given IV at higher dosage or too quickly can cause death – several reports of this last season.
  • Not “legal”; USEF working on threshold levels.


  • substances – be careful of what may or may not be in them!


  • Must be withdrawn 7 days prior unless used for a therapeutic reason. Does not include shipping, clipping, floating, mane pulling or shoeing.

Forbidden substances include:

  • Bronchodilators such as Ventipulmin
  • Antihistamines such as hydroxyzine and Tri-Hist.
  • Caffeine – No coffee for your horse or Chocolate (theobromine).
  • Devil’s Claw, lavender, passionflower and valerian root.
  • Furosemide (Lasix)
  • Guafenisin (cough suppressant)
  • Procaine penicillin

AQHA differences from USEF

  • Isoxsuprine – OK but has limits on amounts.
  • Dexamethasone – similar to USEF.
  • NSAIDs – only 1 allowed.
  • Furosemide – Allowed 4 hours out

D) Race Drugs 

  • 1 NSAID (bute, flunixin or ketoprofen) allowed 24 hours before race
  • Furosemide allowed 3-4 hours before race depending on jurisdiction – helps prevent bleeding
  • Other bleeder medications are illegal, but not always tested for, and are short-acting
  • Erythropoeitin – “Blood doping”: increases stamina but can cause death (fatal anaphylactic reactions). Illegal.
  • Cobra venom, cone snail venom – blocking agents
  • Anabolic steroids – illegal since 2008
  • Horses coming off track usually “clean” of drugs, although trainers will often give bute or Banamine themselves
  • ACTH, thiamine (vitamin B1), MgSO4 – quieting effects (illegal)
  • All FDA-approved drugs also have withdrawal periods, as with USEF, but they differ from state to state

E. Generic Drugs

  • Generic refers to a drug name not protected by a trademark. i.e. Flunixin meglumine (Banamine).
  • These drugs are FDA-approved but no longer under patent.
  • Note: When a drug is approved by the FDA, the manufacturer receives rights to that drug for a certain amount of time. The drug companies often spend years of time and millions of dollars to do research to have a drug approved.
  • Drugs that currently have trade rights include Regu-Mate and GastroGard. There are no valid generic forms of these drugs.


F. Compounded Drugs

  • Refers to medications that are mixed by compounding pharmacies and are not FDA-approved
  • These are allowed in veterinary medicine by a prescription, ONLY if there is no similar FDA-approved product available
  • For example, compounded omeprazole is illegal, because there is an FDA -approved product available (GastroGard, UlcerGard).
  • Compounded drugs are NOT guaranteed for safety, efficacy or actual amount of drug present. They can be both ineffective and dangerous to use.



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