Veterinary chemicals

Veterinary chemicals are drugs or medicines used to treat or prevent disease, injury and pests in animals.

Without them the welfare of livestock, domestic animals and native fauna would be impacted. It would also compromise livestock productivity.

The Agricultural and Veterinary Chemicals (Control of Use) Act 1992 controls the use of veterinary chemicals.

Safe use of veterinary chemicals and following good agricultural practices:

  • prevents antibiotic resistance in animals which may impact human health
  • prevents unacceptable residues in livestock products – which can impact domestic and export market access for Victoria’s livestock industries.

See our legislation page for further information.

Over-the-counter veterinary chemicals

Over-the-counter veterinary chemicals are available from veterinary chemical retailers and rural merchandise stores.

Examples include:

  • vaccines
  • worm drenches
  • lice treatments.

Off-label use

Livestock owners treating major species, such as cattle, sheep, pigs or chickens, with over-the-counter veterinary chemicals must use a registered product for the intended purpose or obtain written authorisation from a registered veterinarian to use the product contrary to the label directions.

Livestock owners treating minor species such as goats, alpacas and turkeys may be legally able to use these products off label, depending upon how they want to use the chemical.

See our Off-label use of veterinary chemicals page for further information.

Withholding period

When using veterinary chemicals off label livestock owners must also use a sufficient withholding period (WHP) to ensure there is no risk of unacceptable chemical residues occurring. The WHP specified on the label applies to the use pattern on the label and may not be suitable for an off-label use pattern.

Livestock owners are also not permitted to sell treated stock animals before all WHPs have expired unless the purchaser is advised of this in writing on the National Vendor Declaration/PigPass (or similar applicable document). This notification requirement also applies in situations where stock have entered land that has been treated with an agricultural chemical and the WHP has not expired (e.g. stock have broken through a fence and grazed a paddock that was sprayed with an insecticide and the WHP has not expired). For more Information about these requirements, visit the National Livestock Identification System.

Prescription animal remedy veterinary chemicals

Prescription animal remedy products, such as antibiotics, are legally available only from a veterinarian for animals under their care. These products are easily differentiated from over-the-counter products as they contain the phrase 'Prescription Animal Remedy' on the front label of the product.

Follow label directions

These products must only be used in strict accordance with the label directions or the written directions of the dispensing veterinarian. These instructions can be provided in two different ways:

  • labels printed by the veterinarian are attached to each container of the product sold
  • advice notes provided by the veterinarian when the product is dispensed or at the time treatment starts.

Use only for prescribed purpose

A prescription animal remedy dispensed for the treatment of an animal cannot be used to treat an animal not specified on the label/advice note. A person not complying with this requirement risks their ability to possess these chemicals in the future. This may have a big impact on their activities.

A veterinarian cannot dispense prescription animal remedy products to treat animals unless:

  • the client is a bona fide client with records to prove this
  • the veterinarian has established a therapeutic need
  • the veterinarian has responsibility for and current knowledge of the health of the animals and has records that support this.

The Drugs, Poisons and Controlled Substances Act 1981 places complementary controls over the supply, possession and use of prescription animal remedies. The Veterinary Practitioners Registration Board of Victoria also regulates these same activities through their registration responsibilities.

Provide separate written advice note

When treating livestock with a prescription animal remedy and no ongoing treatment is required, veterinarians should provide the livestock owner with a written advice note containing the same information that is required on the product label. This enables the livestock owner to keep the appropriate chemical use records and adhere to relevant WHPs.

Product supplied without a label

Any prescription animal remedy product that does not have a label  or an advice note supplied by the veterinarian should be reported to Agriculture Victoria on 136 186 or email

Key pages

Record keeping — Understand the record keeping requirements of using veterinary chemicals, plus information on record keeping requirements for veterinarians. Access to Agriculture Victoria's record keeping templates to assist you with your record keeping obligations.

Residue management — General information about preventing unacceptable residues in all agricultural produce, withholding periods and export slaughter interval information for vets.

Off-label use of veterinary chemicals — Requirements for legal off-label use of prescription and over the counter veterinary chemical products.

Chemical use legislation — This page provides links to the relevant Acts, regulations, orders and prohibitions associated with veterinary chemical use.

Veterinary practitioner requirements — Information specifically for Veterinarians regarding labelling, advice notes, withholding periods, record keeping and 'do not' statements on labels.

Page last updated: 28 Feb 2024