Senior Horse Medications: Uses & Dosing Reference
An educational reference to common senior horse medications: bute, firocoxib, pergolide, omeprazole, and gabapentin, with uses, typical dose ranges, and vet-first cautions.
Quick answer: Every medication on this page is prescription-only and must be prescribed and dosed by your veterinarian. This chart is an educational reference to help you understand what common senior horse drugs do, not a prescribing guide. The most-used ones are phenylbutazone (bute) and firocoxib (Equioxx) for pain and arthritis, pergolide (Prascend) for PPID, omeprazole (GastroGard) for gastric ulcers, and gabapentin for nerve pain. Never give, combine, or adjust these without veterinary direction. Doses vary by body weight, organ function, and the individual horse.
Common Senior Horse Medications at a Glance
The table below summarizes typical uses, the general dosing concept, and key cautions for medications frequently prescribed to older horses. Dose figures are broad textbook ranges given per kilogram or per pound of body weight to illustrate scale only. They are not instructions. Your veterinarian sets the actual product, dose, frequency, and duration for your horse.
| Medication | Primary Use | Typical Dose Concept (Rx only) | Key Cautions |
|---|---|---|---|
| Phenylbutazone (bute) | NSAID for pain and inflammation, lameness, arthritis | Commonly ~2.2 to 4.4 mg/kg orally, often once or twice daily, lowest effective dose | Ulcers, right dorsal colitis, kidney damage; risky long-term in seniors; never stack NSAIDs |
| Firocoxib (Equioxx) | COX-2 selective NSAID for chronic arthritis pain | Commonly ~0.1 mg/kg orally once daily | Gentler on gut than bute but still an NSAID; never combine with another NSAID |
| Pergolide (Prascend) | PPID (equine Cushing's) management | Often started ~2 mcg/kg once daily, titrated by ACTH testing | Possible temporary appetite drop; dose adjusted on lab results; lifelong therapy |
| Omeprazole (GastroGard) | Gastric ulcer treatment and prevention | Treatment commonly ~4 mg/kg once daily; lower dose for prevention | Confirm with gastroscopy when possible; give correctly relative to feeding per vet |
| Gabapentin | Off-label neuropathic and chronic pain | Variable, individualized; oral absorption inconsistent | Evidence still developing; part of multi-modal pain plans; vet-directed only |
Important: The dose figures above are illustrative textbook ranges, not prescriptions. Do not use them to medicate your horse. Underdosing can fail to help and overdosing can cause ulcers, colitis, kidney failure, or toxicity. Only your veterinarian can weigh your horse's age, organ function, other drugs, and condition to set a safe dose.
Why Pain Control Is Tricky in Older Horses
Senior horses often need long-term help with arthritis and chronic pain, yet they are also the most vulnerable to NSAID side effects. Aging kidneys and a higher risk of dehydration and ulcers mean the margin for error is smaller. This is why vets reach for the lowest effective dose, prefer COX-2 selective options like firocoxib for daily use, add gastric protection when appropriate, and reassess regularly with bloodwork. Good pain control in a senior is a balance managed over time, not a fixed prescription.
PPID and Lifelong Medication
Pergolide is a once-daily, usually lifelong medication for PPID. It does not cure the disease but controls the overactive pituitary, which in turn lowers laminitis risk, improves coat shedding, and helps preserve muscle. Because the right dose changes with the horse and the season, vets titrate it using follow-up ACTH testing rather than a one-size figure. Pairing pergolide with a low-NSC diet is the cornerstone of managing a metabolic senior.
Always Loop In Your Vet
Use this page to understand what your vet may prescribe and why, then let your veterinarian make every dosing decision. Report any new signs such as reduced appetite, diarrhea, dark or tarry manure, lethargy, or changes in drinking and urination, since these can signal medication side effects. Never share medications between horses, never combine NSAIDs, and never stop a drug like pergolide abruptly without guidance. Safe medication is a partnership with your veterinary team.
Related Reading
- PPID ACTH Testing Chart - The lab testing that guides pergolide dosing.
- Senior Horse Vital Signs Chart - Baselines that help you spot a medication problem.
- Low-NSC Horse Feeds Brand Chart - The diet half of PPID and EMS management.
- Plants Poisonous to Horses - Toxins that may need emergency veterinary care.
This page is educational reference only and is not veterinary advice or a prescribing guide. All medications listed are prescription-only. Consult your veterinarian before giving, changing, or stopping any medication.
Frequently Asked Questions
Is this chart a substitute for my veterinarian?
No. This is an educational reference only. Every medication listed is prescription-only and must be dosed by a licensed veterinarian who knows your horse. Doses depend on body weight, kidney and liver function, other medications, the specific condition, and the individual horse. Giving any of these drugs without veterinary direction risks serious harm, including ulcers, kidney damage, and toxicity. Always call your vet before starting, changing, or stopping a medication.
Why is phenylbutazone (bute) used carefully in senior horses?
Bute is a non-steroidal anti-inflammatory (NSAID) widely used for pain and inflammation, but it carries real risks, especially in older horses. Prolonged or high-dose use can cause gastric ulcers, right dorsal colitis, and kidney damage. Seniors are more vulnerable because of reduced organ reserve and dehydration risk. Vets aim for the lowest effective dose for the shortest time, often reassessing or switching to a more targeted NSAID like firocoxib for chronic arthritis.
How is firocoxib (Equioxx) different from bute?
Firocoxib is a COX-2 selective NSAID, meaning it targets inflammation while sparing more of the protective COX-1 pathway in the gut and kidneys. For many senior horses with chronic arthritis, vets prefer it for long-term daily use because it tends to be gentler on the stomach than bute at equivalent anti-inflammatory effect. It is still an NSAID, so it is not risk-free, and it should never be combined with another NSAID. Dosing is once daily by prescription.
What does pergolide (Prascend) treat, and how is it dosed?
Pergolide is the standard treatment for PPID (equine Cushing's disease). It is a dopamine agonist that calms the overactive pituitary, reducing high ACTH and improving signs like long coat, laminitis risk, and muscle loss. It is usually started low and titrated up based on follow-up ACTH testing and response. Some horses show a temporary appetite dip when starting. Dose, increases, and monitoring are set entirely by your vet using lab results.
When is omeprazole (GastroGard) needed?
Omeprazole is the leading treatment for equine gastric ulcer syndrome, suppressing stomach acid so ulcers can heal. It is commonly used as a treatment course at a higher dose, then sometimes a lower preventive dose during stressful periods like travel, stall confinement, or NSAID therapy. Seniors on long-term bute may be given gastric protection. Diagnosis ideally follows gastroscopy, and dosing and duration are directed by your veterinarian.
Is gabapentin used in horses?
Yes, gabapentin is used off-label in horses for neuropathic and chronic pain, such as nerve-related lameness or laminitis pain, often alongside other medications. Evidence in horses is still developing, and oral absorption can be variable, so vets individualize the dose and frequency. It is prescription-only and is typically part of a multi-modal pain plan rather than a stand-alone fix. Never start or adjust it without veterinary guidance.
Can I give two NSAIDs together to control pain better?
No. Stacking NSAIDs, for example bute plus firocoxib or bute plus flunixin, sharply increases the risk of ulcers, colitis, and kidney injury, and it is a common cause of serious harm. If one NSAID is not controlling pain, the answer is to call your vet, not to add a second. Your vet may adjust the dose, switch drugs, add gastric protection, or layer in a different class of pain control like gabapentin instead.
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