[en] The development of an effective regulatory system for genetically engineered animals and their products has been a subject of increasing discussions among researchers, industry and policy developers, as well as the public. Transgenic technology alters an animal's genome to achieve desired production or health effects of commercial or societal value. Since transgenesis itself is a relatively new scientific approach, transgenic animals are new organisms for which there is no existing information relevant to their performance under domestication or to their behavior in the wild, nor is there any firm basis for predicting their potential. The issues associated with the regulation and biosafety of transgenic animals pertain to environmental impact, human food safety, animal health and welfare, trade, and ethics. Many concerns related to genetic modifications in animals or plants focus on safety of the human food chain. Given the present public perception of animal biotechnology in general, transgenic animals are viewed with varying degrees of optimism and skepticism. In light of these divergent views the question that remains to be answered is how to develop regulations that safeguard the public concerns and at the same time allow this technology to benefit agriculture, in a manner that neither 'restricts' nor 'facilitates'. Transgenic animals are produced for four basic reasons: to improve animal health, to increase productivity and improve product quality, to mitigate the environmental impact of foodanimal production, and to produce therapeutics. To date, scientists have been able to add, delete, silence or partially activate genes of interest. To regulate such a powerful technology predicated on limited background information is a challenge not only to the regulators, but also to the developers who strive to prove that these animals are safe by demonstrating bioequivalency to their conventional counterparts. The regulations are based on the principle of substantial equivalence from the point of view of human food safety, and data is required to elucidate molecular characterization, nutritional similarities, and toxicological studies to substantiate that the animal product is safe. To address the concerns connected with the environmental release of transgenic animals, the regulatory framework should take into account the ability of genetically modified animals to survive and compete with the conventional populations. They should consider biosafety issues to prevent adverse effects of genetic modification on bio-diversity and to prove that the animals have no negative environmental impact. The challenge to regulate the animal health component of transgenic animals is addressed by animal welfare considerations and risk assessments, to ensure that such animals are not susceptible to diseases or acting as vectors for disease promoting organisms by virtue of their transgenic origin. An effective regulatory filter can permit safe products while forming a secure barrier for those that pose an unacceptable risk. However, even though extrapolation of regulatory principles from the Canadian system may be adaptable in developing countries, there remains a wide scope for improvements, just as the Canadian system is undergoing further development. The fast pace at which methodological advancements are currently being introduced indicates that the regulatory system will have to be constantly reviewed, altered and improved in a manner that keeps up with the technological leaps in order to address the public concern over transgenesis in agriculture