Medical Devices vs Drugs in Horses: What Horse Owners Should Know 🐎💉

By Dr Duncan Houston

Quick Answer

Drugs are medications that are approved and regulated to treat specific diseases in horses, while medical devices are products designed to assist medical procedures but are not approved to treat disease. Even if some devices contain similar ingredients to approved drugs, they are not tested, regulated, or proven to work the same way.

Joint health is one of the most common concerns in horses, especially for performance animals and aging companions. From injectable medications to supplements, horse owners are presented with many treatment options. Unfortunately, confusion often arises around an important distinction: the difference between a drug and a medical device.

Understanding this difference can help you avoid ineffective treatments, unnecessary costs, and potential risks to your horse.

🧠 Why This Distinction Matters

When a horse develops joint inflammation or arthritis, veterinarians aim to reduce pain, protect cartilage, and maintain mobility.

However, not every injectable product marketed for joints is actually approved to treat joint disease. Some products are legally classified as medical devices rather than drugs, which means they are regulated differently.

This difference affects:

💊 Safety testing
🧪 Clinical evidence
📜 Approved uses
⚖️ Legal responsibility

Knowing which category a product falls into helps ensure your horse receives evidence-based treatment.

💉 What Is a Veterinary Drug?

A drug is a medication approved by regulatory authorities to treat a specific disease or condition.

In the United States this approval comes through the FDA Center for Veterinary Medicine (CVM). In many other countries similar regulatory bodies exist, such as the APVMA in Australia or EMA in Europe.

To receive approval, drugs must undergo rigorous testing to demonstrate:

🧪 Safety
📊 Effectiveness
⚖️ Correct dosage
🧬 Pharmacology and metabolism

Examples of well known injectable joint medications for horses include:

Legend® (Hyaluronic Acid)
Typically administered intravenously to help reduce joint inflammation.

Adequan® (Polysulfated Glycosaminoglycan / PSGAG)
Administered intramuscularly and designed to support cartilage health and slow degenerative joint disease.

These medications have:

✔ Established dosing protocols
✔ Clinical studies supporting their use
✔ Defined safety guidelines
✔ Manufacturer accountability

Because they are regulated drugs, veterinarians and owners have reliable information about how they work and how to use them safely.

🔧 What Is a Medical Device?

A medical device is defined differently from a drug.

Devices include tools or substances intended to assist a medical procedure or provide mechanical support, rather than chemically altering body function.

Common examples of medical devices include:

🩺 Surgical instruments
💉 Syringes and needles
🦴 Orthopedic implants
🧪 Certain injectable lubricants

Some injectable products used in equine medicine are legally classified as devices rather than drugs.

Examples sometimes used in horses include:

Polyglycan®
MAP-5®
Chondroprotec®

These products may contain ingredients similar to drug formulations, such as hyaluronic acid or glycosaminoglycans. However, they are typically approved for surgical lavage or reproductive procedures, not for treating arthritis or joint disease.

That distinction is critical.

⚠️ Why Devices Are Sometimes Used Off Label

Some owners and trainers choose these products because they may be:

💰 Less expensive
🗣 Recommended by others at the barn
🏆 Used informally within competitive circles

However, using a device in place of a drug introduces several risks.

⚠️ Risks of Using a Medical Device as a Drug

❌ Limited Clinical Testing

Medical devices are not required to undergo the same level of clinical testing for disease treatment as drugs.

This means their effectiveness for arthritis or joint disease may not be proven.

💉 Sterility and Injection Risks

Joint injections require extremely strict sterility. Even small contamination can lead to septic arthritis, a serious and painful joint infection.

Products not designed specifically for intra-articular use may carry higher risks.

📉 Unclear Dosage Information

Approved drugs have precise dosing instructions based on controlled studies.

Devices may not include dosing guidance for treating joint disease, which can lead to:

⚠ Under-dosing (ineffective treatment)
⚠ Over-dosing (potential complications)

⚖️ Limited Manufacturer Liability

When a product is used outside its approved indication, manufacturers are often not responsible for adverse outcomes.

This places more risk on both the veterinarian and the owner.

🩺 Questions Horse Owners Should Ask

If a product is recommended for your horse’s joints, it is reasonable to ask your veterinarian a few key questions.

📜 Is this product a drug or a medical device?
💉 Is it approved for injection into joints, veins, or muscles?
🧪 Are there studies supporting its use for arthritis in horses?
📊 What are the expected benefits and potential risks?

Clear answers help ensure your horse receives safe and appropriate care.

📉 When Cheap Alternatives Become Expensive

Veterinary medicine often sees cases where attempts to save money lead to costly complications.

For example, if a product not designed for intra-articular use is injected into a joint and contamination occurs, a horse can develop septic arthritis.

Treatment may require:

🏥 Hospitalisation
💉 Repeated joint lavage
🧪 Antibiotic therapy
🐎 Months of recovery

In performance horses, this can mean the loss of an entire competition season.

🧪 Evidence Based Joint Care

The best joint care programs for horses usually combine several approaches.

These may include:

🐎 Controlled exercise programs
⚖ Weight management
💊 Evidence-based medications
💉 Properly administered joint injections
🧬 Nutritional support when appropriate

Working with a veterinarian experienced in equine sports medicine helps ensure treatments are both safe and effective.

🐾 Final Thoughts

In equine medicine, the difference between a drug and a medical device is more than a technical label.

It reflects how thoroughly a product has been studied, tested, and regulated.

When treating arthritis or joint inflammation in horses, medications with proper approval and clinical evidence provide the most reliable results and the lowest risk.

Understanding what is being injected into your horse helps protect both their performance and long term health.

❓ FAQ

Are medical devices always unsafe for horses?

No. Many devices are extremely valuable for surgical or reproductive procedures. The concern arises when they are used to treat diseases they were not approved for.

Why are FDA approved drugs more expensive?

The cost reflects years of research, clinical trials, and regulatory approval needed to prove safety and effectiveness.

Can veterinarians legally use products off label?

Veterinarians can prescribe drugs off label in certain circumstances under veterinary guidance. However, using a product classified as a device in place of an approved drug may carry additional legal and safety considerations.

Are joint injections common in horses?

Yes. Joint injections are frequently used in sport horses to manage inflammation and maintain comfort when performed appropriately.

If you ever want help tracking lameness, monitoring recovery, or organising your animal’s medical records, the ASK A VET™ app can help keep everything in one place while allowing you to ask veterinary questions whenever you need guidance. 🐎📱