Trisha Dowling, professor of veterinary clinical pharmacology at the University of Saskatchewan’s Western College of Veterinary Medicine, and Ron Johnson, associate professor of biomedical sciences at Ontario Veterinary College, say unacceptable drug residues in food can be avoided. Both are directors of the global Food Animal Residue Avoidance Databank.
Consumers want food that is safe, affordable and nutritious. The number of high profile food safety incidents such as the European E. coli outbreak has heightened consumer awareness and suspicions regarding the safety of their food.
Read Also
Agriculture needs to prepare for government spending cuts
As government makes necessary cuts to spending, what can be reduced or restructured in the budgets for agriculture?
Livestock and poultry producers have a role to play in ensuring consumer confidence in food of animal origin.
To produce safe and wholesome products, producers may need to prevent and treat animal diseases with drug products.
When a drug is approved by Health Canada’s Veterinary Drug Directorate for use in food animals, there are label directions for withholding the animal from slaughter and other products, such as milk and eggs, from sale to ensure that unsafe drug residues do not enter the human food supply.
However, there may be situations where an approved drug does not meet the animal’s needs.
Extra-label use of a drug is adminis-tering a drug in a manner not specified on its label, such as giving a higher dose, giving it more often than directed or giving it to a different type of animal than what it was approved for.
Canadian veterinarians follow a three-step decision process when choosing drug therapy:
• They first must choose an approved veterinary product and administer it according to its label directions.
• If such a situation does not exist, Canadian veterinarians may then choose to use an approved veterinary product in an extra-label manner.
• Only if there is not a suitable veterinary product available may Canadian veterinarians then choose to use an approved human drug in an animal.
For example, the human tablet formulation of the drug meloxicam was discussed in a recentWestern Producerarticle on controlling pain in calves based on research from the United States.
In Canada, meloxicam is available in an approved injectable product (Metacam7) for use in calves, with specific label directions: “As an aid in improving appetite and weight gains when administered at the onset of diarrhea, in combination with oral rehydration therapy, in calves over one week of age.
For relief of pain following de-budding of horn buds in calves less than three months of age.”
Using it for the relief of pain from castration is an appropriate extra-label drug use as long as the approved injectable formulation is used.
In Canada, it is not appropriate for veterinarians to prescribe human-approved tablets to calves instead of the approved cattle product unless there is a valid reason why the injectable product cannot be used.
When veterinarians have to prescribe extra-label drug use, it is their responsibility to ensure that meat or other food products from treated animals do not enter the food supply with unsafe residues.
However, practising veterinarians do not always have the necessary information to determine safe withdrawal periods for extra label drug use.
In Canada, veterinarians can prevent unacceptable drug residues in food by contacting the Canadian global Food Animal Residue Avoidance Databank (gFARAD) through our website www.cgfarad.usask.ca for advice.
———
access=subscriber section=opinion, none, none
