What are veterinary chemicals?
In general terms, a veterinary chemical product is a substance or mixture of substances that is supplied or used for administration or application to an animal:
- to prevent, diagnose, cure, or alleviate a disease, condition, or infestation by a pest in an animal, or
- to modify the physiology of the animal to
- to alter its natural development, productivity, quality or reproductive capacity, or
- to make it more manageable
- to modify the effect of another veterinary product.
Veterinary chemicals fall into two categories: 'over-the-counter' and 'prescription animal remedy' products.
'Over-the-counter' products are veterinary chemicals that can be readily purchased from most veterinary chemical retailers and rural merchandise stores.
Examples include vaccines, worm drenches and lice treatments.
By law, farmers treating major species (i.e. cattle, sheep, pigs or chickens) with an 'over-the-counter' product must use a product that is registered for the intended purpose, or obtain written authorisation from a veterinary practitioner to use the product contrary to the label directions.
'Over-the-counter' products can be used off-label (i.e. used in a manner not specified on the product label) to treat minor species (e.g. goats, alpacas, turkeys), however a sufficient withholding period (WHP) must be used to ensure there is no risk of unacceptable chemical residues occurring.
When using 'over-the-counter' products, farmers must not use the product:
- at a higher rate than that stated on the label
- more frequently than stated on the label
- contrary to a specific label statement.
Farmers are also not permitted to sell treated stock animals before all WHPs have expired unless the purchaser is advised of this in writing.
'Prescription animal remedy' products
'Prescription animal remedy' products, such as antibiotics, are legally available only from a veterinary practitioner for animals under his/her care.
'Prescription animal remedy' products must only be used according to the directions provided by the dispensing veterinary practitioner. A 'prescription animal remedy' dispensed for one purpose cannot be used for any other purpose without the written permission of the veterinary practitioner.
A veterinary practitioner 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, and
- the veterinarian has responsibility for and current knowledge of the health of the animal/s and has records that support this.
When treating stock animals with a 'prescription animal remedy' and no ongoing treatment is required, veterinary practitioners must provide the farmer with a written advice note containing the same information that is required on the product label. This enables the farmer to keep the appropriate chemical use records and adhere to relevant WHPs.