Controlled Substance Schedules & Common Veterinary Drugs (II

Almost every compliance rule your practice follows starts with one question: what schedule is the drug? The schedule drives how it has to be ordered, how it has to be stored, how the records have to be kept, and how tightly access has to be controlled. Yet the schedules are one of the things staff are least sure about — and a drug in the wrong bucket is a gap waiting to be found.

This guide explains the five DEA schedules in plain English and shows where the controlled drugs a veterinary practice actually uses tend to fall. Treat the drug lists as a working orientation, not a legal classification — always confirm the current schedule of a specific product with the DEA and your state, because classifications change and states can be stricter than the federal government.

What the schedules mean

The Controlled Substances Act sorts drugs into five schedules, ordered by their potential for abuse and dependence against their accepted medical use. Schedule I is the most restricted; Schedule V is the least.

Schedule I — no accepted medical use and high abuse potential. Not used in normal veterinary practice.
Schedule II — accepted medical use, but the highest abuse and dependence potential of the drugs you can stock. The tightest controls: Form 222 or CSOS ordering, separate records, strict security.
Schedule III — moderate-to-low physical dependence and high psychological dependence potential. Less restrictive ordering than Schedule II, but full controlled-substance recordkeeping still applies.
Schedule IV — lower abuse potential than Schedule III. Common in veterinary sedatives and analgesics.
Schedule V — the lowest abuse potential. The fewest restrictions, but still controlled.

The practical dividing line for ordering is Schedule II versus everything else: Schedule II requires the Form 222 / CSOS channel, while Schedule III–V do not. But storage, logging, inventory, and access controls apply across all schedules a practice handles.

Where common veterinary drugs tend to fall

The drugs below are grouped by the schedule they are commonly assigned. Brand names are examples, not an exhaustive list — and because a product’s schedule can depend on its exact formulation, always verify the specific product.

Schedule II — the tightest controls

Fentanyl — injectable and transdermal
Hydromorphone
Morphine
Methadone
Oxymorphone
Hydrocodone
Pentobarbital — including many euthanasia solutions (see the note below)
Carfentanil — large-animal immobilization

These are the drugs that draw the most attention in an inspection, because they carry both the highest diversion risk and the strictest ordering, storage, and recordkeeping requirements.

A note on euthanasia solutions: Pentobarbital-only euthanasia products are commonly Schedule II, while some combination euthanasia solutions (for example, those combining pentobarbital with another agent such as phenytoin) are classified as Schedule III. The euthanasia solution on your shelf is one of the most important drugs to classify correctly — check the specific product’s labeling and confirm its schedule.

Schedule III — full records, easier ordering

Ketamine
Buprenorphine (e.g., Buprenex, Simbadol)
Tiletamine/zolazepam (Telazol)
Ketamine-containing combinations
Anabolic steroids (e.g., stanozolol, boldenone) and testosterone products

Schedule III drugs — ketamine and buprenorphine in particular — are workhorses in many practices and are also frequently diverted, which is why they still require complete logs, secure storage, and reconciliation despite the easier ordering channel.

Schedule IV — common sedatives and analgesics

Butorphanol (Torbugesic, Torbutrol)
Diazepam (Valium)
Midazolam
Phenobarbital
Tramadol
Alprazolam
Pentazocine

Schedule IV is where a lot of everyday veterinary sedation and pain control lives. The lower schedule does not mean “log it casually” — these still require controlled-substance records and secure storage.

Schedule V — the lowest tier, still controlled

Certain low-concentration codeine preparations
Diphenoxylate/atropine (Lomotil)

Schedule V carries the fewest restrictions, but the drugs are still controlled — they belong in your secured storage and your records.

Watch the drugs that move — and the ones your state adds

Two things trip practices up beyond the basic lists.

Reclassifications happen. Drugs move between schedules. Tramadol became a federally scheduled (Schedule IV) drug, and hydrocodone combination products were moved from Schedule III to Schedule II. If your policies were written years ago, some of your classifications may be out of date — a good reason to review them periodically.

States can be stricter than the DEA. A number of states have added drugs to their own controlled lists that are not federally scheduled — gabapentin is the clearest example, scheduled or monitored in several states even though it is not a federal controlled substance. Others impose tighter recordkeeping or reporting than the federal baseline. Your practice has to meet whichever rule is stricter, so your drug list has to reflect your state, not just the federal schedules.

Free download: Once your drug list is right, the next question is whether your storage, logs, and records match it. Our DEA Self-Audit Checklist turns that into a self-scoring worksheet across every inspection category. Get the free Self-Audit Checklist →

Why the schedule drives everything else

Getting the schedule right is not academic — it sets the requirements that follow:

Ordering — Schedule II needs Form 222 or CSOS; III–V do not.
Storage — all schedules belong in secure, locked storage, with the tightest attention on Schedule II.
Records — Schedule II records are kept separate from the rest; III–V may be separate or readily retrievable.
Access — the higher the schedule and the higher the diversion risk, the tighter the list of people who can touch it should be.

A single misclassified drug quietly breaks the rule that depends on it — a Schedule II euthanasia solution logged like a Schedule IV, or a state-scheduled drug left out of the records entirely.

Frequently asked questions

What schedule is ketamine for veterinary use? Ketamine is commonly classified as Schedule III. It still requires full controlled-substance records and secure storage despite the easier ordering channel — and it is a frequently diverted drug.

What schedule is a euthanasia solution? It depends on the product. Pentobarbital-only solutions are commonly Schedule II; some combination euthanasia solutions are Schedule III. Confirm the specific product’s schedule.

Is tramadol a controlled substance? Yes — tramadol is federally scheduled (Schedule IV). Some states apply additional requirements.

Is gabapentin a controlled substance? Not federally, but several states have scheduled or added monitoring requirements for gabapentin. You must follow your state’s rule if it is stricter than the federal one.

Which drugs get the most attention in an inspection? Schedule II drugs and high-diversion-risk Schedule III drugs like ketamine and buprenorphine, because they carry the highest accountability and the greatest diversion risk.

Build your policy on the right classifications {#lead-magnet}

Your controlled-substance program is only as accurate as the drug list underneath it. If the schedules are wrong or out of date, every downstream rule inherits the error.

Run the free DEA Self-Audit Checklist to see whether your storage, logs, and records line up with the drugs you actually stock. And when you want the system behind it, the Vet Compliance HQ DEA Controlled Substance Compliance System gives you the SOPs, logs, and training records to handle every schedule correctly — built around federal DEA recordkeeping concepts and ready to adjust to your state.

Get the free DEA Self-Audit Checklist →

Vet Compliance HQ provides educational compliance resources for veterinary practices. This article is not legal advice. Drug classifications change and vary by state — verify the current schedule of any specific product with the DEA and your state veterinary board.