Baycox (toltrazuril) is a veterinary drug manufactured by Bayer Animal Health that has been in use in Canada since 1992 to treat a parasitic infection in newborn piglets. This infection can spread through swine herds very quickly and could result in large production losses if left untreated.
While never approved for sale in Canada, Baycox was available from 1992 to 1998, through Health Canada’s Emergency Drug Release program, and from 1998 to present was released to a limited number of veterinarians who acted as clinical investigators under the Investigational New Drug Submission program.
Before approving a drug under an Investigational New Drug Submission, Health Canada evaluates and approves data submitted by the manufacturer. Applicants for an Investigational New Drug Submission must follow the requirements specified under the Food and Drug Regulations related to safety, dosage and effectiveness of the drug.
Veterinarians participating in the program were responsible for prescribing Baycox and for evaluating its use. The data from these evaluations was submitted to Bayer who used the information for further research. According to Bayer, between two and four per cent of the 32 million pigs produced in Canada each year may have been treated with Baycox.
Under the terms of the Investigational New Drug Submission, veterinarians had to ensure that piglets treated with Baycox lived an additional 70 days before entering the food chain. This allowed the drug sufficient time to break down into what was considered a safe level at that time. The vast majority of pigs reach the weight of 100-120 kilograms before slaughter. A very small percentage are slaughtered at a lesser weight as barbecue pigs.
After the filing of the Investigational New Drug Submission, Health Canada undertook a thorough review of the scientific data relating to the safety and efficacy of Baycox. At the conclusion of this review, Health Canada determined that the risks associated with the use of Baycox outweigh the benefits.
As a result, Health Canada notified Bayer on June 13, 2005, that the Investigational New Drug Submission for Baycox was rescinded. Bayer subsequently stopped distribution of the product and recalled all remaining units of Baycox.
As an added precaution, Health Canada has now requested that any remaining pigs that were treated with Baycox live an additional 150 days or grow to a weight of at least 100 kilograms.
In terms of human health concerns, given the very low levels of Baycox residues that would be present in pork products from treated, market-weight pigs, the probability of adverse health consequences is considered remote. Canadians can be confident that pork is safe to eat.
Baycox is not approved for use in the United States. Baycox has been approved, however, for use in the European Union and Australia.
Health Canada is working with the Canadian Food Inspection Agency to develop testing procedures to monitor both domestic and imported pork products to make certain Canadian regulations are respected.
Questions and Answers About Baycox
What is Baycox?
Baycox is a veterinary drug with the active ingredient toltrazuril. It is considered to be effective for the treatment of a parasitic infection (coccidiosis) in newborn piglets.
While never approved for sale in Canada, Baycox was available from 1992 to 1998, through the Emergency Drug Release program, and from 1998 to present was released to a limited number of veterinarians who acted as clinical investigators under the Investigational New Drug Submission program.
What is the issue?
Health Canada recently reviewed available data for Baycox that has been in use in Canada since 1992 to treat a parasitic infection in newborn piglets. Health Canada scientists concluded that, based on the data provided, they could not rule out the potential for Baycox to cause cancer in humans.
Consequently Health Canada has rescinded the Investigational New Drug Submission for Baycox, notifying the manufacturer Bayer Inc. on June 13, 2005. Bayer subsequently stopped distribution of the product and recalled all remaining units of Baycox from investigators.
Is my health at risk if I have eaten pork that may have been treated with toltrazuril?
Given the very low levels of toltrazuril residues that would be present in pork products from treated market-weight pigs, the probability of adverse health consequences is considered remote. Since there is no immediate health threat, Health Canada is not recommending any specific course of action to consumers who may have eaten pork products treated with Baycox.
Can the public feel confident that pork is safe?
The public can feel confident that pork is safe to eat. The Canadian Pork Council and the Canadian Hog Producers have a stringent Quality Assurance Program in place based on the internationally recognized Hazard Prevention Critical Control Point (HACCP) model. The Canadian Food Inspection Agency recognizes the technical merits and effectiveness of the program. For further information please visit http://www.cqa-aqc.ca.
How many pigs have been treated with Baycox?
According to Bayer, since 1998, approximately two to four percent of the 32 million pigs raised each year in Canada may have been treated with Baycox.
What are producers doing with animals that have been treated with Baycox?
As a precautionary measure, Health Canada has extended the stipulated withdrawal period (the period that pigs must live after being treated with Baycox) from 70 days to 150 days or until the treated pig reaches typical market weight (100 kg).
The extended withdrawal period will allow residues of the drug to be metabolized below detectable levels, thereby ensuring that the slaughter of remaining pigs already treated with Baycox does not pose a risk to human health.
Baycox has been recalled from all clinical investigators and is no longer available for use in Canada.
Are there alternative drugs that can be used to treat the parasitic infection (coccidiosis) in piglets?
Currently, there are no products approved for the treatment of the parasitic infection (coccidiosis) in pigs in Canada. However, there are alternatives that are available in other countries for the treatment of this condition. These drugs could be made available in Canada through the Veterinary Drugs Directorate’s Emergency Drug Release Program.
Why did it take so long to assess the safety of this drug?
Since the initial application for an Investigational New Drug Submission for Baycox, additional data was collected. In addition, scientific research has evolved over past years.
Health Canada reviewed available data, including new scientific evidence, and concluded that the the risks associated with the use of Baycox outweigh the benefits.
What does the Government of Canada do to ensure the safety of foods derived from animals treated with veterinary drugs?
When it comes to veterinary drugs and the federal government, two departments have primary responsibility for maintaining the safety of Canada’s food supply. Health Canada’s Veterinary Drugs Directorate evaluates and monitors the safety, quality and effectiveness, sets standards, and promotes the prudent use of veterinary drugs administered to food-producing animals. The Canadian Food Inspection Agency routinely monitors for veterinary drug residues in foods derived from treated animals. Should the Canadian Food Inspection Agency identify any drug residue violations through its monitoring program, it will take appropriate action to protect the health of Canadians.
How can I keep up-to-date on this issue?
At this point, Baycox is no longer available for use in Canada. If new information about this veterinary product issue becomes available, Health Canada’s Veterinary Drugs Directorate will continue to provide information on our web site.
Health Canada contact information:
Veterinary Drugs Directorate
Health Products and Food Branch
Holland Cross Complex, Ground Floor
14 - 11 Holland Avenue
Ottawa, Ontario. K1A 0K9
Address Locator - 3000A
General Information Number: (613) 954-5687
Fax: (613) 957-3861
Media Relations Officer: Jirina Vlk 957-2988