Animals in Teaching and Research in the Americas: Analysis of Legislation

Analysis of direct and/or indirect mention of animal protection in national constitutions.

The direct mention refers to the explicit and objective description of animal protection within the legal text, whereas an indirect mention pertains to the protection of the environment, of which fauna is a component, implying that animals are indirectly protected under the law. Indirect mentions of animal protection are present in the constitutions of most of the countries analyzed (21 out of 35). For instance, the Brazilian Constitution, in Article 225, states:

“everyone has the right to an ecologically balanced environment, an asset for common use by the people and essential to a healthy quality of life, imposing on the Government and the community the duty to defend and preserve it for present and future generations.”⁸

Item VII of that document further stipulates that it is the responsibility of public authorities “to protect fauna and flora, prohibiting, in accordance with the law, practices that jeopardize their ecological function, lead to the extinction of species, or subject animals to cruelty.”⁹ From the legal text, it can be inferred that animal protection is implicitly addressed within this article and item. Based on this legal provision, the country established its animal protection laws, including the Arouca Law, which regulates the use of animals in teaching and research activities. It is worth noting that the preamble of this law references the constitutional text, highlighting the connection between the 2 legal instruments.^8,10,11

Among the countries analyzed, only Bolivia and Guyana included both direct and indirect mentions of animal protection in their constitutional text. The indirect mention pertains to the State’s responsibility to preserve and conserve the environment. The direct mention is found in Article 302 of the Bolivian Constitution, which specifies that municipal governments have exclusive authority to preserve, conserve, and contribute to the protection of the environment, natural resources, wildlife, and domestic animals.¹² Ingunza¹³ also highlights this direct reference to animal protection in the Bolivian constitutional text.¹² Conversely, 14 of the 35 countries studied, Antigua and Barbuda, Bahamas, Barbados, Canada, Dominica, Grenada, Honduras, Nicaragua, Saint Christopher and Nevis, Saint Lucia, Saint Vicent and the Grenadines, Suriname, Trinidad and Tobago, and United States, lacked both direct and indirect mentions of animal protection. Table 1 summarizes the presence or absence of these mentions in the constitutional texts of the analyzed countries.

Analysis of the presence of specific laws related to the use of animals in teaching and research activities and generic animal protection laws, with or without specific provisions on the subject.

Regarding the presence of specific laws related to the use of animals in education and research, as well as generic animal protection laws, among the 35 countries analyzed, 32 had generic laws, while only 8 had specific laws. The countries were categorized into 4 groups:

• 1)

  Countries with specific laws governing the use of animals in teaching and research, which include Bahamas, Belize, Brazil, Grenada, Guyana, Jamaica, Mexico, and Uruguay (8 out of the 35 countries analyzed).

• 2)

  Countries with generic laws that include provisions on the subject, comprising Argentina, Chile, Colombia, Costa Rica, Cuba, Dominican Republic, El Salvador, Guatemala, Guyana, Honduras, Nicaragua, Panama, Paraguay, Peru, Uruguay, United States, and Venezuela (17 out of the 32 countries with general laws).

• 3)

  Countries with generic laws that lack specific information on the use of animals in teaching and research, represented by Antigua and Barbuda, Bahamas, Barbados, Belize, Bolivia, Brazil, Canada, Dominica, Grenada, Jamaica, Saint Christopher and Nevis, Saint Lucia, Saint Vincent and the Grenadines, Suriname, and Trinidad and Tobago. (15 out of the 32 countries with general laws).

• 4)

  Countries without specific or generic laws addressing the subject, which include only Ecuador and Haiti (2 out of the 35 countries analyzed).

In the first group of countries with specific laws, the Mexican law, Norma Mexicana 062-ZOO-1999, was enacted in 2001. Nearly a decade later, Brazil implemented its specific regulation, Law No. 11.794/2008, followed by Uruguay with the enactment of Law No. 18.611/2009 the following year.^11,14,15 The Brazilian and Uruguayan regulations share similarities not only in their dates of enactment but also in their scope. Both laws apply to animals within the phylum Chordata and subphylum Vertebrata, as stated in Article 3 of each law. Furthermore, Article 4 in Chapter II of both laws establishes national bodies responsible for overseeing activities involving the use of animals in teaching and research. In Brazil, this is the National Council for the Control of Animal Experimentation (CONCEA), while in Uruguay, it is the National Commission for Animal Experimentation (CNEA).^11,15

The Mexican legislation, however, exhibits notable differences compared with Brazilian and Uruguayan laws. It is composed of 15 chapters and 5 appendices, offering a broader scope of content. The Mexican norm provides detailed information about animal biology and handling, facilities, transportation, experimental techniques, euthanasia, and biosafety. In contrast, Brazilian legislation addresses these topics separately in specific Normative Resolutions issued by CONCEA.^11,14

Another significant distinction lies in the inclusion of animal species. The Mexican law specifies the animals covered, including rodents, lagomorphs, dogs, cats, pigs, and nonhuman primates. In contrast, Brazilian and Uruguayan laws encompass all vertebrate animals without further specification.^11,14–16 None of these countries have included invertebrate animals in their regulations. According to Botero and Gómez,¹⁷ Mexico, Brazil, and Argentina are among the most advanced countries regarding animal protection legislation. However, Argentina has yet to enact a law specifically regulating this matter.¹⁷

Bahamas, Belize, Grenada, Guyana, and Jamaica are the other countries with specific legislation on this topic. All have laws that are quite similar in terms of structure and content. In addition, they also resemble Brazil, Mexico, and Uruguay in the scope of their laws, which apply only to vertebrate animals.^{9,11,14,15,18–21} On the other hand, unlike Brazil, Mexico, and Uruguay, the laws of these countries do not provide much detail. They are limited to specifying the types of activities requiring licensing restrictions and the necessity of using anesthetics to ensure animal welfare, except in cases where anesthesia could interfere with research outcomes.^9,18–21

In these countries, the granting of licenses for activities is carried out by Ministers, while in Belize, the Director of the Health Service is mentioned, and in Guyana, the Chief Medical Officer. License holders must allow their activities to be monitored at any time and, when requested, must submit reports on them.^9,18–21 In contrast, Brazil and Uruguay have specific regulatory bodies for licensing and monitoring activities: CONCEA in Brazil and CNEA in Uruguay.^11,15 In Mexico, this responsibility falls under the Secretaría de Agricultura, Ganadería y Desarrollo Rural (MEXICO 1999).

Based on the results found, in 6 of the 8 countries that have specific legislation regarding the use of animals in education and research activities, a direct or indirect mention of animal protection was observed in the constitutional text. This observation is relevant as it demonstrates the influence of national constitutions on the regulation of animal use in education and research. The presence of direct or indirect references to animal protection in constitutional texts indicates a broader legal commitment to animal welfare, serving as a foundation for the creation of specific legislation. Moreover, this relationship suggests that countries with constitutional protection tend to develop more structured regulations aligned with international ethical principles, reinforcing the importance of constitutional recognition for the effective implementation of laws aimed at protecting and ensuring the responsible use of animals in scientific activities.

For the second group of countries with generic laws that address animal protection and include references to the use of animals in teaching and research, the legislative content varies significantly across the nations.

In the United States, the evolution of the relevant legal framework is particularly noteworthy. The Animal Welfare Act (AWA), first enacted in 1966, underwent several updates (8 amendments). In a 2002 amendment, rats and mice were excluded from its scope, leaving these 2 critical species for biomedical research unprotected to this day.^22,23 Despite this gap, the United States boasts a highly significant scientific output involving animal models, as highlighted by Taylor and Alvarez.²⁴ Further, there are also important guidelines that guide activities involving animals to ensure their welfare, like the guidelines for the humane transportation of research animals, and the guidelines for the welfare and use of animals in cancer research.²⁵

In 1965, AAALAC International was established in the United States. It is a nonprofit organization committed to promoting the humane treatment of animals used in scientific research. It offers voluntary accreditation and independent evaluations of animal care and use programs at research institutions. It is important to highlight that this accreditation is not limited to American institutions; organizations from any country around the world are eligible to apply. Additional information about AAALAC International can be found at the end of this section.²⁵

Another important American institution is the Office of Laboratory Animal Welfare (OLAW), an agency responsible for ensuring the ethical and humane use of animals in research funded by the government. OLAW oversees and enforces the guidelines of the Policy on Humane Care and Use of Laboratory Animals, which establishes standards for research involving animals. The agency provides guidance on the Policy, supports educational programs, and monitors compliance with the guidelines at institutions receiving government funding, thereby ensuring the humane and ethical use of animals in research, testing, and training. OLAW requires institutions to base their animal care and use programs on the Guide for the Care and Use of Laboratory Animals, developed by the Institute for Laboratory Animal Research (ILAR) and used worldwide. The Guide is internationally accepted as a reference for animal care and use and serves as a foundation for the creation of laws in various countries, guiding activities involving animals, especially in nations without specific regulations.^24–27

In this context, the Policy on Humane Care and Use of Laboratory Animals is a key regulatory framework established by the U.S. Public Health Service to ensure the ethical and humane treatment of animals used in research, testing, and education. Institutions that wish to obtain government funding must submit a document called Animal Welfare Assurance (AWA), in which they outline how they will comply with the Policy, which must be approved by OLAW. In addition, every institution is required to have an Institutional Animal Care and Use Committee (IACUC) to review, approve, and monitor experimental protocols involving animals, in addition to complying with the Guide, and adhere to principles that promote animal welfare. The Policy sets standards for the housing, care, and use of laboratory animals, emphasizing the 3Rs principle to minimize animal suffering while ensuring scientific integrity. It also mandates regular reviews, training, and compliance monitoring to uphold ethical research practices. It is worth noting that institutions must report any deviations to OLAW, which has the authority to investigate and impose sanctions in cases of noncompliance.²⁵

Regarding the principles that promote animal welfare, the United States has the U.S. Government Principles for the Utilization and Care of Vertebrate Animals in Testing, Research, and Training, which establish ethical guidelines for the humane use of animals in scientific studies. They emphasize the 3Rs, proper veterinary care, and minimizing pain and distress. These principles apply to federally funded research and promote responsible animal welfare. Institutions must ensure compliance through oversight committees and ethical review processes.^25,28

It is important to highlight the creation of the Health Research Extension Act in 1985, a legal instrument applicable to the use of animals in activities that receive government funding, which included the chapter “Animals in Research” in its final section. This legislation not only provided essential information regarding the necessary care in activities involving the use of animal models but also introduced guidelines for the establishment of animal care and use committees, ensuring compliance with directives related to the ethical use and welfare of animals, just like the AWA Amendment, which was enacted in the same year.²⁹ The information regarding these 2 regulatory instruments related to the committees will be addressed in the analysis of specific and generic laws with regard to animal care and use committees.

Another country worth mentioning is Cuba, which enacted a new animal welfare law in 2021. Cuban legislation, specifically Article 47, stands out from all other countries by defining experimental animals as including both vertebrates and invertebrates, thereby broadening the scope of legal protection.³⁰ This approach demonstrates a significant advancement in addressing the ethical treatment of all animals used in research activities. The global scientific community has increasingly discussed the sentience of invertebrate organisms, a crucial issue for advancing ethical considerations in scientific research and animal welfare policies. Emerging studies suggest that certain invertebrates, such as cephalopods and certain arthropods, exhibit complex behaviors, learning abilities, and pain responses, challenging traditional assumptions about their cognitive and sensory capacities. Recognizing their sentience may lead to more humane treatment, fostering the development of regulations that ensure ethical handling during research activities. Addressing invertebrate sentience is essential for establishing inclusive, science-based animal protection frameworks.^31–33

In the third group, comprised of countries with generic laws that do not include provisions related to the use of animals in teaching and research activities, Canada stands out. Although Canada lacks a generic law addressing these activities or a specific law, it established the Canadian Association for Laboratory Animal Science (CALAS) in 1961 to provide training for institutions using animals. In addition, the Canadian Council on Animal Care (CCAC), founded in 1968, sets guidelines and certifies institutions, ensuring ethical use and animal welfare. Certification by the CCAC is mandatory for institutions seeking government funding, similar to practices in the United States. The importance of these organizations is reflected in the robust Canadian scientific output involving animal models, as highlighted by Taylor and Alvarez.^24,26,34 It is also noteworthy that the Canadian province of Ontario has its own specific law, the Animals for Research Act, which regulates the use of animals for teaching and research within its jurisdiction.³⁵

It is important to mention that, in 2009, the “3Rs Program” was established by the CCAC with the aim of promoting and implementing these principles in activities involving the use of animals in education and research in the country. Similar to the United States, the CCAC created the Guide to the Care and Use of Experimental Animals, which provides guidelines for these activities nationwide. This Guide incorporated the Guiding Principles for the Care of Experimental Animals, created by the Canadian Federation of Biologic Societies (CFBS) in 1961, the first set of guidelines for the use of animals in education and research in Canada.³⁴

The fourth and final group consists solely of Ecuador and Haiti, both countries lacking specific or general laws regulating the use of animals in teaching and research. However, in 2021, Ecuador issued a comprehensive resolution outlining the establishment and operation of animal care and use committees. While this resolution represents a significant step forward in regulating the ethical use of animals, it was not classified as a specific or general law in this study, as its scope is limited to committees.^36,37 Table 2 provides an overview of the countries and their corresponding laws.

As previously mentioned, any institution located anywhere in the world may apply for accreditation with AAALAC International, and accreditation demonstrates compliance with standards that promote excellence in the responsible care and use of animals in research, teaching, and testing. The accreditation process involves an internal evaluation of the animal care program; submission of documentation detailing protocols, infrastructure, and institutional policies; on-site assessments conducted by AAALAC experts to review compliance with standards; and the approval and maintenance of accreditation through periodic site visits. This accreditation is important as it demonstrates a commitment to ethical practices and animal welfare in research, facilitates international recognition of scientific studies, and may also be a requirement for funding and scientific collaborations. AAALAC International assists in harmonizing and continuously improving research animal welfare practices, based on performance standards.²⁵

It is important to note that although AAALAC International is headquartered in the United States, it employs a personalized approach to evaluating programs in different countries, taking into account the applicable laws and regulations of the host country. According to information available on the organization’s official website, among the countries analyzed in this study, Barbados, Brazil, Canada, Colombia, Mexico, Peru, and Saint Christopher and Nevis have accredited institutions, in addition to the United States itself. Another important point is the cost involved in the accreditation process, which may limit access, especially in countries facing financial challenges, since it requires the payment of an application fee and subsequent annual fees, in addition to expenses related to any necessary facility or program upgrades.²⁵

From the analysis of the presence of generic laws, with or without specific provisions, and specific regulations, their existence can support the pursuit of ethical animal use and welfare in teaching and scientific research activities. However, their mere existence does not guarantee these objectives, as other factors must also be present. Without sufficient resources, such as the necessary infrastructure, supplies for carrying out activities, and qualified personnel, as well as awareness, commitment, and willingness from all involved individuals, the presence of guiding regulations will not be sufficient.

Analysis of specific and generic laws with regard to animal care and use committees.

Oversight committees play a crucial role in ensuring the ethical use and care of animals in teaching and research activities. Among the countries analyzed, 9 were found to have laws related to committees: Brazil, Colombia, Cuba, Ecuador, Guatemala, Mexico, Peru, the United States, and Uruguay. In the Americas, they are commonly referred to as the Comitê de Ética no Uso de Animais (CEUA), Comite Institucional de Cuidado y Uso de Animales de Laboratorio (CICUAL), and IACUC.^74–76 In countries with specific laws, such committees follow the relevant regulations to approve and oversee the execution of projects. The importance of these committees is particularly evident in countries without specific laws, where they have acted to ensure the welfare of animals. Yunta⁷⁷ stated that, to guarantee the best possible treatment, every institution that uses animals should establish an institutional committee for the use and care of laboratory animals to oversee the experiments conducted.

Based on the analysis, in 3 countries (Brazil, Mexico, and Uruguay) that have specific legislation regarding the use of animals in teaching and research activities, animal care and use committees were described, along with the mandatory establishment of such committees in institutions that use animals for these purposes. Among these countries, as previously mentioned, Brazilian and Uruguayan laws share similarities with respect to the committees. In Chapter III, Article 9 of both laws, the creation of animal care and use committees is mandatory for institutions that use animals for teaching and research activities. In both countries, the committees have very similar responsibilities, and it is important to note that in Brazil, there are specific normative resolutions addressing issues related to the functioning of the committees.^11,15,78,79 The Mexican regulation also specifies, in Item 4.2.2, the information about their functioning.^14,80

The group of countries that have generic laws containing specific information about animals used in teaching and research includes Colombia, Cuba, Guatemala, Peru, and the United States. These countries have specific provisions in their laws regarding animal care and use committees, and they mention the mandatory establishment of such committees at each institution that uses animals for these purposes. In the United States, the creation of IACUCs became mandatory only after 1985 for institutions which fall under the purview of the AWA, AAALAC International, or the Health Research Extension Act (HREA). In the United States, the IACUC is responsible for reviewing and approving proposed research and teaching projects and ensuring that they comply with regulations, as well as the standards described in the Guide for the Care and Use of Laboratory Animals. It is important to mention that the establishment of the IACUC is specified by 2 regulations: the AWA Regulations (AWAR) and the Health Research Extension Act, both enacted in 1985. The HREA expects institutions to apply the Guide for the Care and Use of Laboratory Animals, and that document notes an expectation that institutions should form and support an IACUC. Compliance with the AWAR versus the HREA depends on the nature of the activity being conducted. If the activity involves species covered by the AWA but does not use federal funding, the AWAR will guide the establishment of the IACUC. However, if federal funding is involved, the HREA will apply. If the activity does not involve species covered by the AWA and does not receive federal funding, an IACUC will not be required for the development of the activities, unless the institution is accredited by AAALAC, International.^22,29

In Guatemala, Decree No. 5/2017 provides, in Article 44, for the creation of institutional animal care and use subcommittees according to the needs of the institution. This was not observed in the regulations of the countries studied. The Brazilian Normative Resolution No. 51/2021 includes the possibility of having more than one animal care and use committee in institutions, provided that it is approved by CONCEA.^57,78

In Argentina, Canada, Chile, Costa Rica, Dominican Republic, Nicaragua, Panama, and Saint Christopher and Nevis, existence of institutional oversight committees were also noted, even though such obligations are not present in the laws of these countries. The Chilean law differs in that it mentions the establishment of a permanent national bioethics committee, detailing its composition. However, this law does not require the mandatory creation of institutional committees, although such committees do exist in the country.⁴⁸

In Ecuador, the Resolution No. 227/2021 provides detailed information about the mandatory requirement for institutional oversight committees, as well as regulations related to their functioning. This resolution³⁶ has enabled greater control over activities involving the use of animals in the country, which was previously quite ineffective and superficial before its publication. This perception supports the findings of Bustos and Terán.⁸¹ Table 3 presents the presence of these committees in the analyzed countries along with the associated legislation.

The composition of the committees varied among the countries analyzed. In Brazil, veterinarians, biologists, professors, researchers, and representatives of animal protection societies are part of the committees.¹¹ In Colombia, the committee is to include a veterinarian from the Colombian Agricultural Institute, a representative from the authority managing natural resources, and a representative from an animal protection society.⁴⁹ In Ecuador, the committee is to be composed of veterinarians, researchers, and members of civil society.³⁶

In Guatemala, the legislation provides for the presence of veterinarians, notable citizens, researchers, and other individuals necessary for the functioning of the committee.⁵⁷ The Mexican legislation stipulates that the committee should be composed of veterinarians, researchers, and other individuals as needed.¹⁴ In Uruguay, the legislation requires the presence of veterinarians, professors or researchers, and representatives from the local community.¹⁵ In the United States, the AWAR requires the committee to be composed of at least 3 members. Among these, one must be a veterinarian, and another must not be affiliated with the institution to which the committee belongs.²² The Health Research Extension Act mandates the establishment of committees with at least 5 members. Among them, one must be a veterinarian, one a scientist, one a nonscientist, one a member who is not affiliated with the institution, and one additional member of free choice.²⁹

The legislation of Brazil, Colombia, Ecuador, Mexico, the United States, and Uruguay specify the duties of animal care and use committees. The Cuban and Peruvian legislations, despite determining the mandatory establishment of the committees, do not specify their composition or duties.^30,51,64 Guatemalan legislation also does not specify the responsibilities of the committees.^56,57 Figure 1 shows the overall flowchart of a project submitted to the committee.

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As observed in Figure 1, it is the responsibility of the committee to monitor activities related to approved projects. This responsibility is reflected in the text of several regulations listed in Table 3, as well as in the frequency with which they occur. In Brazil, for example, regulations state that committees must “establish preventive programs and conduct inspections to ensure the operation and adequacy of the facilities under their responsibility, in accordance with the standards and norms defined by CONCEA.” However, Brazilian regulations do not specify the frequency of these inspections.⁷⁸ In Colombian law, committees are required to “conduct inspections at least 4 times a year in animal study areas within each laboratory and experimental center.”⁴⁹ Similarly, Ecuadorian law states that “field visits must be conducted at least once a year to the institution, laboratory, or animal facility that requested project approval for research or educational purposes.”³⁶ The monitoring of approved education and research projects by committees is essential to ensuring compliance with ethical and welfare standards. Ongoing oversight helps prevent misconduct, promotes adherence to regulations, and ensures that the use of animals is justified and humane. Regular evaluations also foster improvements in animal care practices and research methodologies. Robust monitoring mechanisms enhance transparency, accountability, and the responsible use of animals in scientific and teaching activities.

Despite the previously mentioned importance of the oversight committee, several challenges hinder their operation, even in countries where their establishment and functioning are supported by law.^{80,82,83,85,98} Frías-Álvarez and Ortiz-Millán⁸⁰ conducted a study assessing the status of these committees in Mexico. Their findings revealed that only 54% of institutions conducting activities with animals had an established committee, a concerning percentage, as it raises issues regarding ethical and welfare standards. Institutions lacking proper oversight may fail to fully adhere to both national and internationally recognized animal care and use standards. Among the key challenges identified in the study were the lack of support for committee members, the absence of standardized evaluation criteria for research and education projects, and regulatory insufficiencies.^80,82

Jankoski and Fischer⁸³ analyzed the animal care and use oversight committee in the Brazilian context and identified challenges such as the general lack of committee members trained in bioethics, an expertise seen as essential to the evaluation of proposed projects. They also highlighted the lack of regular training for both committee members and other personnel involved in animal-based activities.⁸³ Notably, in Brazil, the CONCEA published Normative Resolution No. 49 in 2021, mandating the training of personnel involved in educational and scientific research activities using animals.⁸⁴ Another challenge, discussed by Mohan and Foley⁸⁵ and applicable to any committee, concerns the level of detail provided by researchers to committee members, which is crucial for a comprehensive project evaluation. In addition, the existence of well-designed research protocol forms was described as essential to guide researchers in accurately completing their submissions, ultimately improving the quality of the information provided. In Brazil, Normative Resolution No. 52/2021 establishes the unified forms used in the country to request authorization for the use of animals in teaching or scientific research, and that form a template designed to capture the necessary information for a comprehensive evaluation by the committee.⁷⁹

In the literature, there is a lack of studies that foster a broader discussion about the challenges faced by committees in carrying out their activities. Based on the studies mentioned regarding the Brazilian and Mexican frameworks, countries identified in this study as having specific laws, it can be expected that such obstacles are present not only in other nations across the South American continent but also in many other countries worldwide, especially those frequently facing political and financial challenges. Given the importance of these committees, this scenario is concerning as it may hinder the pursuit of animal welfare and ethical practices in activities involving animals.

Analysis of specific and generic laws related to the use of animals in teaching and research activities regarding the presence of the principle of the 3Rs (Replacement, Reduction, and Refinement).

The ethical and humane use of animals is crucial to ensure their welfare and, consequently, the validity of the relevant research results. It is well known that several factors can negatively affect research outcomes, many of which also impact the welfare of the animals.^86,87 The 3Rs principle, proposed over 60 y ago, continues to guide teaching and research activities involving animals. In the legal documents analyzed, this principle was observed in 29 of the 35 countries presented in this study, within the scope of the main laws (both specific and generic).

Replacement is described as a consideration in 14 of the 29 countries where the 3Rs principle was observed. The search for alternative methodologies to animal use has intensified in recent decades, and the presence of this principle in the regulations of these countries supports this trend. During project evaluations by animal care and use committees, one of the first points often assessed by reviewers is the existence of alternative methods.^78,88 Studies by Duarte and colleagues^89–91 and Tyagi and colleagues⁹² emphasize the importance of developing new alternative methodologies to replace the use of animals in teaching and research activities.

If alternative methodologies are unavailable, the principles of Reduction and Refinement should be considered. The importance of adopting these 2 additional principles when circumstances do not allow replacement of animals is highlighted in studies by Akkermans and colleagues⁹³ and Barkus and colleagues.⁹⁴ The most frequently observed principle in the analyzed laws was refinement (26 out of 29 countries), while reduction was the least observed (7 out of 29 countries). The 3Rs principles were not identified in the legal documents of Bolivia, Canada, Ecuador, Haiti, Honduras, and Saint Vincent and the Grenadines.^44,47,59,68

Regarding countries with specific laws on the use of animals in educational and research activities, the 3Rs can be easily identified in Brazilian and Uruguayan regulations. In Brazilian law (Law No. 11, 794/2008), it is stated that the introduction of alternatives to the use of animals must be evaluated and monitored (replacement); the number of animals used in experiments must be the minimum necessary to obtain conclusive results (reduction); and experiments that may cause pain and/or distress must adopt sedation, analgesia, and/or anesthesia (refinement).^11,16 Uruguayan legislation (Decree No. 78/2014), in Chapter II, which addresses the conditions for breeding, use, and transportation of animals, specifies that all activities involving the use of animals must adhere to the internationally established 3Rs principles. In addition, the decree contains passages that state: “alternative methods shall be used;” “methods shall be those that use the smallest number of animals;” and “the method that can provide the most satisfactory results and cause the least pain, suffering, and distress shall be selected,” which correspond to the 3Rs, respectively.^16,72

In contrast, Mexican legislation (NOM-062-ZOO-1999) reflects these principles in the excerpts: “To achieve reliable results in scientific research (…) the smallest possible number of animals must be used (…)” (reduction); and “...all methods used must be selective for each animal species or circumstance, must be applied quickly, and, if possible, must be painless. If they are invasive and capable of inducing significant discomfort in the subject, sedative or anesthetic substances or drugs must be used” (refinement). However, the regulation does not explicitly mention the principle of replacement.^14,16 In the other countries with specific legislation (Bahamas, Belize, Grenada, Guyana, and Jamaica), only the principle of refinement is described and relates to the use of anesthetics during experimental procedures to prevent pain and suffering in animals.^9,18–21

Among the other analyzed countries where the 3Rs principle was observed, Costa Rica, Cuba, and Guatemala stand out. Even though these countries do not have specific legislation on the matter, all 3 Rs were identified within general laws containing information on the use of animals in educational and research activities. In US legislation, both the HREA and the AWAR contain direct references to the 3Rs. These include “methods of testing that do not use animals are being and continue to be developed, which are faster, less expensive, and more accurate than traditional animal experiments for some purposes, and further opportunities exist for the development of these methods of testing” (replacement); “measures which eliminate or minimize the unnecessary duplication of experiments on animals” (reduction); and the need for “proper treatment of animals while being used in such research (…), the appropriate use of tranquilizers, analgesics, and appropriate presurgical and postsurgical veterinary medical and nursing care for animals in such research” (refinement).^25,28,29

Overall, the presence of principles related to the 3Rs in 29 out of the 35 analyzed countries demonstrates that the concept proposed by Russell and Burch over 60 y ago is widely adopted in legislation and guidelines across the Americas. Table 4 presents the countries where the presence of the 3Rs principle was verified in the analyzed documents, along with the specific “Rs” that were observed.

Analysis of specific and general legislation regarding the presence of information on requirements for facilities, housing and care of animals, and personnel responsible for using and caring for animals.

The inclusion of clear requirements for facilities, housing, and care of animals, as well as the qualifications and responsibilities of personnel handling them, in legislation is essential in the pursuit of animal welfare and ethical research practices. Well-defined legal standards help maintain humane conditions, minimize pain and distress, and promote the proper treatment of animals used in research and teaching. In addition, these regulations provide guidance for institutions, allowing personnel to be adequately trained and ensuring that facilities meet appropriate standards. Among the 8 countries with specific legislation on the use of animals in teaching and research activities, only Brazil and Mexico have legal instruments that provide guidelines on the requirements for facilities, housing and care of animals, and personnel responsible for using and caring for animals. The Mexican legislation (NOM-062-ZOO-1999) consists of 59 pages, within which item 6 outlines the requirements for facilities, item 4 details the requirements for housing and care for each animal species covered by the standard, and items 4 and 10 specify the qualifications and responsibilities of personnel handling animals. In addition, the standard also addresses information on animal transportation, experimental techniques, and euthanasia methods.¹⁴

In Brazil, the specific law (Law No. 11.794/2008) and its decree (Decree No. 6.899/2009) do not provide such information.^11,45 However, Brazil has Normative Resolutions published by CONCEA that establish guidelines for activities involving animals. Among them are Normative Resolution No. 55 of October 5, 2022, which refers to the Brazilian Guidelines for the Care and Use of Animals in Teaching or Scientific Research Activities;⁹⁷ Normative Resolution No. 49 of May 7, 2021, which concerns the training of personnel involved in teaching and scientific research activities using animals⁸⁴; and Normative Resolution No. 37 of February 15, 2018, which establishes guidelines for euthanasia practices.⁹⁵ Normative Resolutions No. 57 to 67, published between 2022 and 2023, address the conditions that must be observed for the breeding, maintenance, and experimentation of animals housed in facilities of educational or scientific research institutions, where the requirements for facilities for each class of vertebrate animals covered by the law are specified. It is important to mention that the normative resolutions issued by CONCEA have the force of law in Brazil. They are mandatory regulations that complement and detail the implementation of Law No. 11.794/2008, the specific regulation for the use of animals in teaching and scientific research activities.

In addition, the country has the Brazilian Guide for the Production, Maintenance, or Use of Animals for Teaching or Scientific Research Activities, also published by CONCEA, which also contains information (requirements for facilities and housing and care of animals) concerning different animal classes (amphibians, birds, mammals, fish, reptiles), guiding activities conducted in the country.⁹⁶

In the other countries analyzed, the legislation examined (constitutions, general animal protection laws, and specific laws on the use of animals in education and research) did not provide detailed information regarding the requirements for facilities, housing, and care of animals, as well as for the qualifications and responsibilities of personnel handling the animals. The lack of detailed information may pose a challenge to best practices in the use of animals for education and research. However, this gap is often addressed through complementary national guidelines, which lack legal force, and internationally recognized documents such as the Guide for the Care and Use of Laboratory Animals, which establish widely accepted standards for animal welfare.

Although the adoption of these guidelines and documents is essential, interpretations may vary, resulting in a lack of standardization in implemented practices. Furthermore, the absence of such information in national legislation hinders oversight and institutional accountability, as overall effectiveness depends on the formal incorporation of these principles into national regulations and the commitment of institutions to the application of such standards. The development of more detailed regulations aligned with international standards can be expected to strengthen animal welfare and allow greater uniformity in the ethical and responsible use of animals in research, teaching, and testing.

Conclusion.

The presence of regulations guiding the use of animals in teaching and research activities is essential in the pursuit of ethical practices related to animal welfare. However, the significant disparity among the legal frameworks of the analyzed countries reveals weaknesses in the oversight and enforcement mechanisms for these activities. While some nations have well-defined laws, others lack specific guidelines and standards, leading to inconsistencies in the protection of animals used in research and education. Another important aspect is that the mere existence of laws, whether specific or general, may not be sufficient to achieve these objectives. It is necessary to have available resources, such as financial support, adequate infrastructure, and qualified personnel, as well as awareness and commitment from all involved parties. Despite the availability of internationally recognized guidelines, a lack of legal legitimacy makes compliance with such guidelines optional in countries without specific legislation. This weakens the role of animal care and use committees in enforcing such guidelines and hinders the implementation of corrective measures in cases of noncompliance. A possible approach would be the establishment of unified guidelines across American nations, setting minimum standards for animal welfare and ethical use, similar to the European Directive 2010/63/EU.

Animal Care and Use Committees also play a fundamental role in the pursuit of the responsible use of animals, especially in countries where there are no specific national laws or where generic animal protection laws lack detailed provisions. The committee function extends beyond regulatory compliance, promoting ethical research and educational practices based on the 3Rs principle. Some countries have legal mandates requiring the establishment of these committees, while others rely on voluntary institutional initiatives. Strengthening these committees through standardized protocol templates, adequate resources, proper infrastructure, and continuing training is essential for improving the quality of scientific and educational activities and, consequently, animal welfare. This contributes to the responsible use of animals in scientific research and education, balancing scientific progress with ethical considerations.

Regarding the 3Rs principle, “reduction” was the least observed in the legal documents analyzed. Encouraging its implementation is imperative, especially in cases where replacement is not yet feasible. Refinement strategies should also be reinforced to minimize pain and distress, ensuring humane treatment in all scientific and educational activities. Addressing these issues through targeted policy interventions and awareness programs would ensure more consistent ethical and responsible scientific practices.

Ultimately, the advancement of laboratory animal science in the Americas depends on the improvement of regulatory frameworks, mutual collaboration, and a commitment to ethical responsibility. By adopting harmonized and comprehensive legal measures, countries can promote transparency, accountability, and the humane treatment of animals in scientific endeavors. Establishing international collaborations and shared guidelines is essential for advancing ethical animal research while maintaining scientific excellence. Moreover, as previously mentioned, the availability of resources, awareness, and the commitment of all stakeholders is foundational. When combined with appropriate legal frameworks, these factors significantly enhance the possibility of achieving ethical animal care and use while fostering scientific progress.