As discussed in other parts of this site, there must be a transition to lower levels of animal product consumption and fewer animals on the landscape (see Goal 2 Demand - supply Coordination, Goal 5, Sustainable food, and Goal 9, Human relations with animals). Production extensification becomes more viable in this scenario, which in turn should reduce the need for animal health products and veterinary services. For complementary initiatives related to veterinary pharmaceuticals, see also Goal 5, Protecting genetic diversity, embryos, semen and animals; and Goal 9 Human relations with animals.
Continue reductions in use of medically important anti - microbials (MIA)
Improve available natural health remedies on the Organic PSL and the regulatory system for livestock natural health products
Support vaccine development for priority diseases
Improve environmental assessment
Continue reductions in use of medically important anti - microbials (MIA)
It was first recognized in the 1960s that the unrestricted use of antibiotics would promote antibiotic resistant strains of bacteria (Report of the Joint Committee on the Use of Antibiotics in Animal Husbandry and Veterinary Medicine, 1969; Food and Drug Administration Task Force on the Use of Antibiotics in Animal Feeds, 1972). Unfortunately, most jurisdictions were slow to react.
Canada now collaborates internationally to address AMR, such as the WHO Global Action Plan (GAP) on AMR, and has a guiding framework that includes food system interventions. The framework claims to be using a one health approach that recognizes the interconnections between humans, animals and the environment
After years of criticism for weak responses on the agricultural side of the ledger, relying particularly on user education (important but insufficient), the federal government made a number of changes in 2018:
- moving all MIA OTCs to prescription status, putting them under veterinarian oversight
- taking growth promotion claims off MIA labels to encourage treatment use only
- placing responsible use statements on labels of in-feed and in-water MIAs.
The Government of Canada Response has multiple dimensions, including measures for responsible use in animals:
- "supporting the development of on-farm food safety programs:
- including guidance on the responsible use of antimicrobials
- funding research for developing other approaches (including vaccines) to improve animal health and prevent disease while reducing the use of antimicrobials
- increasing veterinary supervision on the use of antimicrobials and requiring that all medically important antimicrobials for veterinary use are sold by prescription only
- supporting the veterinary and farming communities in putting into practice regulatory and policy changes for use of veterinary drugs
- supporting programs that improve the health of farm animals
- encouraging animal hygiene and livestock raising practices that:
- reduce the need for antimicrobials
- help in the prevention and treatment of diseases
- monitoring the use of authorized antimicrobials on animal farms
- educating farmers and farming communities on using antimicrobials responsibly
- removing growth promotion claims from medically important antimicrobial drug labels
- including responsible use statements on all ‘in-feed’ and ‘in-water’ medically important antimicrobial drug labels"
The worry is gram-negative bacterial diseases in animals, for example E. coli, klebsiella, histophilus, mannheimia, pastuerlla, campylobacter, salmonella and leptospira, because these are often treated with antibiotics used extensively in human medicine including aminoglycosides, fluoroquinolones and cephalosporins. Vaccines are promoted as a prevention strategy, with good nutrition, While this is important, vaccines for such gram-negative diseases are more likely to trigger adverse reactions and as a result using more than two at a time is not recommended (Derksen, 2021). It means that vaccines must be carefully employed and not be a primary focus of the strategy.
The 2021 federal budget allocated $28 million for monitoring and reduction in inappropriate antimicrobial use, which is important. But the weakest areas regarding implementation relate to changing the underlying conditions on farms that increase the need for antimicrobials (and sometimes vaccines). Many of the regulatory changes are vital, but intensive production methods that create disease pressures are a force that cannot be substantially mitigated by administrative, educational, research, labelling, and surveillance measures alone. There is some evidence from Scandinavian countries that banning prophylactic use of antimicrobials, for example, will not be very effective unless combined with efforts to change animal production management processes to improve animal health (Bengtsson and Wierup, 2006). Numerous studies have found that just reducing or eliminating antibiotics from intensive production models can increase morbidity and mortality, speaking again to the need for systems change. The Canadian approach to date focuses on reducing misuse, but not reliance on antimicrobials and farming system redesign. While, PHAC progress reports (cf. PHAC, 2016) indicate some very modest progress has been made, it is not commensurate with the scale of the problem.
"[A]ntibiotic consumption is a main driver of selection pressure that contributes to resistance" (Hobæk and Lie, 2019). In other words, large reductions in consumption of animal anti-microbials are required. In France, the UK, Denmark and the Netherlands, reductions of 50% were reported (House of Commons, 2018), with the Netherlands over 60%, the reductions achieved in under 10 years from a 2009 baseline (World Aniimal Protection, the Netherlands). Changes to management have been critical to these successes. Canada does not have consumption reduction targets. Accounting for differences in livestock populations, in Canada in 2017, for example, 11 times more antimicrobials for use in farming were sold by weight than in Sweden which like Norway has restricted approvals for decades. Sweden is much more advanced on the transition to sustainable farming, banned antibiotics as growth promotants in 1986 and also prioritizes approval and use of narrow spectrum anti-microbials which Canada is not prioritizing. This is important because horizontal-transfer of AMR is mitigated with narrow spectrum products. Crticially, Sweden has also reduced use in farm animals of MIAs by 62-92 percent depending on the class since 2009. Canada only reports that 19-32% of farmers do not administer MIAs (for more on the Sweden - Canada comparison, see Dutescu, 2020).
Part of the regulatory strategy must be to ensure antimicrobials are actually needed. Need is wider than just efficacy, which is a Canadian requirement. As discussed, however in the Introduction to this section, in Canada the belief is that the marketplace determines need, not public policy. The Norwegian case is interesting because they have lower levels of AMR which is attributed to a regulatory environment that required need to be demonstrated for drug approval (until the 1990s and EU harmonization). They have lower numbers of approved drugs than most other Western European countries. Their thinking is that without explicit demonstration of need, then drugs are approved that have to be sold and therefore consumption increases unnecessarily. "a new drug should fill a need not already met by currently marketed alternatives, or do so in a better way, such as a lower price." (Hobæk and Lie, 2019).
Canada should establish reduction targets and then make changes to achieve them. Fortunately, the reevaluation program is focused on evaluating the classes of veterinary drugs most important for human treatment. Changing farm conditions are addressed in many parts of this site, particularly Goal 5 Sustainable Food and Goal 9 Human relations with animals. Establishing need provisions in the regulatory approval process is also critical. This might also require that certain copy cat products be removed from the market place in a regulatory review process that parallels what happens in pesticide re-registration.
Focusing on reducing consumption will also presumably have positive impacts for reducing residues generally and on veterinary drug monitoring systems.
At the provincial level, Saskatchewan has expanded its concept of disease so that it may include AMR in it's 2019 Animal Health Act. All provinces and the Yukon should do similarly through their existing legislation. The provinces also have a role to play in reducing consumption via their agricultural extension services. Extension services have been complicit in promoting intensive production systems, and thereby, use of production aids (see also Goal 3, Public research and information dissemination), including antibiotics and hormones. Conventional production intensity is rarely named in extension materials as a possible contributor to ill health. As Departments of Agriculture and units responsible for aquaculture shift their focus more to sustainable food production (see Goal 5, Sustainable food), this indirect promotion of veterinary drugs will progressively decline.
Improve available natural health remedies on the Organic PSL and the regulatory system for livestock natural health products
The Organic Standard PSL serves as an indicator of the kinds of natural health products that can be useful in more extensive production systems. More research is always required on priority challenges. The Organic Science Cluster investigations include alternative treatments for drying off and mastitis, and treating parasites, and improving poultry immunity. Other priorities include recommendations for rearing young dairy calves and pigs, and use of alternate feeds (McKenzie and Hammermeister, 2017).
Further development of such treatments can be considered akin to the minor use pesticide program discussed under Goal 4 Pesticides, Efficiency. A comparable program for livestock health products is required for alternative treatments in sustainable systems since acreage will be low in the near term, and it also links to the need for improvements to the regulatory system for livestock natural health products.
The main focus of the evolving regulatory system for veterinary health products that are not drugs, vaccines, biologics and diagnostics is still safety. Some products are inadmissable (eg., green tea (Camelia sinensis) extract and blue green algae (Aphanizomenon flos-aqua) . The approved list includes substances (e.g., minerals, plants, microorganisms, oils, preparations, amino acids), homeopathic remedies and traditional medicines. Many have label requirements that name restrictions, animals to which they can be administered and approved administration routes.
The new system is not without criticism. There are still challenges getting materials on the list with a notification number. It doesn't appear that mixtures are permitted. There are some complaints about fees. All this speaks to the need for an equivalent minor use program.
Support vaccine development for priority diseases
The regulatory approval system for vaccines is largely reactive, awaiting industry submissions. The most recent assessment summary on the CFIA veterinary biologics web site is from 2018.
An OIE ad-hoc group on prioritization of diseases for which vaccines could reduce antibiotic use identified the a number of priorities reported in Hoelzer et al. (2018a),
Adapting this list to the Canadian context, Health Canada should put out a call for research proposals to improve R&D on the priority vaccines, and provide funding to help with their development. A key challenge though is filtering the technological innovations surrounding new vaccine approaches (cf. Adams et al., 2009; Hoelzer et al., 2018b), against the sustainability, justice and health promotion objectives presented on this site. Many proposed approaches will be very challenging to effectively regulate and will not be compatible.
Improve environmental assessment
It is now widely recognized that the aggregate negative impacts on ecosystems of pharmaceuticals for human, animal and fish are significant and under-addressed by regulators.
Environmental assessments of new veterinary products are carried out under the New Substances Notification regulations (chemicals and polymers) of CEPA, by Health Canada Environmental Assessment Units.
As with many inputs, the environmental assessment requires manufacturer generated data consistent with OECD test protocols for chemicals. designed in the early 1990s when our ecological understanding was decidedly more limited. These protocols have long been criticized by ecotoxicologists as inadequately considered and implemented (see Forbes and Forbes, 1993), but they remain in force because their inherent inadequacies facilitate commercialization (revealed in interviews with OECD officials by Abergel, 2000).
In Canada, consistent with some OECD protocols, ecotoxicity testing requires a “base set” of data that includes acute toxicity for freshwater fish (96 h LC50), acute toxicity for daphnids (48 h LC50) and growth inhibition testing on freshwater algae (growth rate: 72 h ECr50 and/or biomass: 72 h ECb50). Given the kinds of problems that have emerged in soils and plants (e.g., evidence that soil organisms and plants can absorb pharmaceuticals and their metabolities, cf. Berendsen et al., 2010), the obvious question is what the results on these species will tell us about ecotoxicity in soils and plants. "A closer inspection of existing acute fish LC50 data .... reveals differences in orders of magnitude not only between species, but also for the same species between laboratories ...... Single species LC50 data may thus be highly questionable with respect to accuracy and, in more general terms, to toxicological relevance. Furthermore, the significance for environmental risk assessment of the death of individuals after short-term exposure to high toxicant concentrations is low – except in cases of accidental spills." (Braunbeck et al., 2005:88). The protocols and associated models require "...extrapolation from a small number of test species to a vast number of species varying in taxonomy, size, life history, physiology and geographic range ... these presume an underlying interspecific distribution of sensitivities to a toxicant" (Forbes and Forbes, 1993;249), knowledge that is decidedly deficient regarding the relationship between structure and function of many ecosystems and toxicity distribution across species. In other words, the protocols (and associated flawed statistical models) assume that the impacts on a few in specific ecosystems can account for the impacts on the many across a wide range of ecological contexts and structures.
The OECD does have a wider array of test guidelines that include impacts on soil organisms such as collembola, dung flies, earthworms and predatory mites, molluscs and birds (see OECD), but the CEPA regulations do not require they be used for assessment. It may be that they are requested at the discretion of Health Canada assessors. The New Substances Notification regulations (chemicals and polymers) of CEPA should be amended to require a fuller range of soil, aquatic and avian test guidelines for submissions.
