Section 2 | Reading Livestock Medicines Labels

Livestock Medicines
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Veterinary Prescriptions

What is a Prescription?

A prescription is a written (or verbal) order for a medication from a licensed veterinarian.


The prescription communicates information about:

  • The animal(s) to be treated
  • The drug(s) to be used for treatment
  • How the drug(s) are to be used
  • Any special warnings (e.g. withdrawal times)


To dispense a drug means to administer, sell, distribute, or give away a drug. In Ontario, only a veterinarian or pharmacist may dispense a prescription drug. Commercial feed mills may dispense a prescription drug in mixed feed.

Veterinarians are required to leave written instructions with all medicines dispensed at a farm. When the medicines are to be used exactly as described on the label and are dispensed in their original containers, additional written instructions (over and above a written prescription) are not required.


What is on the Prescription?

Information that needs to be included on a written, signed prescription includes the:

  • Name, strength, and quantity of the drug
  • Name and address of the prescribing veterinarian
  • Identity of the animal or group of animals in need of the drug
  • Name of the client
  • Directions for use (dose, route of administration, frequency, and duration)
  • Date (day, month, year) the prescription is issued
  • Withdrawal times
  • Number of refills (if any) permitted
  • The veterinarian’s license number issued by the College of Veterinarians of Ontario (CVO)


Prescriptions for Antimicrobials In-Feed

When a veterinarian prescribes medically important antimicrobials in feed (see Animal Owner FAASTsheet #3), the following must ALSO be included in the prescription:

  • Animal production type
  • Weight or age
  • Type of feed
  • Total amount of feed or feeding period
  • Amount of drug used per tonne
  • Manufacturing instructions
  • Cautions
  • CgFARAD* number if applicable


*CgFARAD = Canadian Global Food Animal Residue Avoidance Database

Globally funded group that provides advice to veterinarians regarding withdrawal times for drugs used in an extra-label manner in food-producing animals.

Prescription Templates

Health Canada and the Canadian Food Inspection Agency (CFIA) have developed a checklist and species-specific prescription templates (ruminants, swine, poultry), to assist veterinarians when writing feed prescriptions. The use of these templates is optional; click below to download the various forms. Visit Health Canada for more information.