Our response to the USDA Animal and Plant Health Inspection Service Request for Information regarding standards for the care of breeding female dogs, as well as the exercise and socialization of dogs under the Animal Welfare Act

U.S. Department of Agriculture
Animal and Plant Health Inspection Service
Regulatory Analysis and Development, PPD
5601 Sunnyside Ave., #AP760, Beltsville, MD 20705

Re: Request for Information – Standards for the Care of Breeding Female Dogs and Exercise and Socialization of Dogs, Docket No. APHIS-2025-1000

Dear Secretary Rollins,

On behalf of Assistance Dogs International (ADI) and the International Working Dog Association (IWDA), we appreciate the opportunity to provide comments on the Request for Information regarding standards for the care of breeding female dogs and the exercise and socialization of dogs under the Animal Welfare Act (AWA).

We commend the U.S. Department of Agriculture Animal and Plant Health Inspection Service (USDA APHIS) for initiating this timely and important review. Advances in canine welfare science, reproductive management, and behavioral development present a valuable opportunity to modernize federal standards through evidence-based, outcome-driven approaches.

ADI, as an accrediting body, represents global leaders in assistance dog breeding, raising, and training. Our 89 accredited programs in the United States operate under rigorous, science-based standards that prioritize health, temperament, and lifelong welfare. Given this depth of experience and data, we respectfully request to be included as active collaborators in the development of updated federal regulations and guidelines related to the breeding, welfare, and exercise of female dogs.

 

1. Advancing Science-Based, Outcome-Focused Welfare Standards

The USDA’s efforts to incorporate scientific evidence into regulatory frameworks are both necessary and commendable. The following sections draw on peer-reviewed research, where available, to inform best practices in the care and management of breeding females. In areas where the scientific literature remains limited or emerging, recommendations are supplemented by established industry standards grounded in decades of outcome-based data. These standards are aligned within the comprehensive animal welfare framework guided by the Five Domains: nutrition, environment, health, behavior, and mental state, ensuring a holistic, evidence-informed approach to promoting positive welfare outcomes across the lifespan of a dog (Mellor et al., 2020).

ADI has established comprehensive breeding standards that may serve as an appropriate roadmap for updating and expanding federal guidance. ADI member organizations operate at the intersection of applied science, veterinary medicine, and animal welfare research. The standards reflected here are not theoretical. They are continuously validated through large-scale, real-world outcomes across diverse programs and dog populations.

  • Mellor, D.J., NJ Beausoleil, KE Littlewood, AN McLean. The 2020 five domains model: Including human–animal interactions in assessments of animal welfare. Animals 2020, 10, 1870. https://doi.org/10.3390/ani10101870

 

2. Discussion | Answers to the questions outlined in the RFI

A. Care Considerations for Breeding Females

Do breeding female dogs require additional veterinary or other care considerations over those for non-breeding dogs? What are the most common health issues documented in female breeding dogs?

Outside of active reproductive stages, breeding females generally require similar care to non-breeding females. However, additional veterinary oversight is necessary during estrus, pregnancy, and lactation. Common diagnoses in breeding populations include otitis externa, gastrointestinal issues, dental disease, and weight-related concerns, with reproductive conditions (e.g., pyometra, mastitis) influenced by age and environment (Hagman, 2022; Lection et al., 2021).

Preventative health practices, including disease screening (e.g., Brucella canis testing), genetic selection, and routine veterinary care, are critical to maintaining health in breeding populations (Santos et al., 2021; LeCuyer et al., 2025). Because of vigilant testing, the prevalence of Brucella canis at ADI locations should be zero.

In the ADI standards, breeding stock must receive routine veterinary care, including veterinary health exams, vaccines, and parasite control. An organization may have different routine care schedules for breeding dogs than for other dogs in its organization, such as recommended vaccination schedules. Additionally, health clearances include testing for genetic diseases and for eye, cardiac, and orthopedic diseases. Health clearances should include pre-breeding exams that review items such as body condition, internal and external parasites, vaccines, complete blood count testing, reproductive fitness, and, for females, a mammary check and vaginal exam (ADI, 2026).

  • Assistance Dogs International (2026). Compliance Guidance Notes 2026. https://assistancedogsinternational.org/clientuploads/Accreditation%20Documents/2026 /2026_Compliance_Guidance_Notes.pdf
  • Hagman R. Pyometra in Small Animals 2.0. Vet Clin North Am Small Anim Pract. 2022 May;52(3):631-657. doi: 10.1016/j.cvsm.2022.01.004. PMID: 35465903.
  • Lection J, Cornelius AJ, Moxon R, Russenberger J, Diel de Amorim M, Cheong SH. Incidence and risk factors for canine mastitis and metritis in two guide dog populations. Anim Reprod Sci. 2021 Aug;231:106802. doi: 10.1016/j.anireprosci.2021.106802. Epub 2021 Jul 7. PMID: 34280749.
  • LeCuyer, Tessa E et al. “Performance characteristics of three Brucella canis serological assays in the United States.” Frontiers in Veterinary Science Vol 12 1556965. 1 Apr. 2025, doi:10.3389/fvets.2025.1556965
  • Santos, Renato L et al. “Canine Brucellosis: An Update.” Frontiers in Veterinary Science Vol 8 594291. 2 Mar. 2021, doi:10.3389/fvets.2021.594291

 

Are there studies regarding the specific nutrition requirements during pregnancy and lactation for breeding females?

Scientific literature supports the importance of maintaining appropriate body condition and providing adequate nutrition during gestation and lactation to support maternal and offspring health (Sones and Balogh, 2023; Kim & Wakshlag, 2023; Greco, 2009). Energy requirements change substantially across reproductive stages. During gestation, caloric needs increase progressively and should be adjusted on an individual basis. In dogs, body weight typically does not increase significantly until the last half to third of gestation, reflecting fetal growth patterns; therefore, caloric intake is generally increased gradually during this period (10%–15% increase each week from the fifth week) (Kim and Wakshlag, 2023). Because weight gain and energy requirements are correlated, careful monitoring of body condition and incremental dietary adjustments are recommended during pregnancy.

Energy demands increase even more dramatically during lactation. Nutritional requirements may increase by 200% to 300% above maintenance needs, particularly in females nursing large litters, and weight loss may still occur despite increased caloric intake (Kim and Wakshlag, 2023). These substantial metabolic demands underscore the importance of energy-dense diets, frequent feeding opportunities, and ongoing monitoring of body condition to support maternal health and milk production.

Per ADI standards, nutritional requirements for dogs during all phases of reproduction should be considered. The body condition of the breeding stock, both pre- and post-breeding, should be maintained through appropriate diet and monitoring (ADI, 2026).

  • Assistance Dogs International (2026). Compliance Guidance Notes 2026. https://assistancedogsinternational.org/clientuploads/Accreditation%20Documents/2026 /2026_Compliance_Guidance_Notes.pdf
  • Greco, Deborah S. “Nutritional supplements for pregnant and lactating bitches.” Topics in companion animal medicine vol. 24,2 (2009): 46-8. doi:10.1053/j.tcam.2009.02.001
  • Kim, Hyun-Tae, and Joseph J Wakshlag. “Nutrition and Theriogenology: A Glimpse Into Nutrition and Nutritional Supplementation During Gestation, Lactation, Weaning and Breeding Dogs and Cats.” The Veterinary Clinics of North America. Small animal practice vol. 53,5 (2023): 1083-1098. doi:10.1016/j.cvsm.2023.05.003
  • Sones, Jennifer, and Orsolya Balogh. “Body Condition and Fertility in Dogs.” The Veterinary Clinics of North America. Small animal practice vol. 53,5 (2023): 1031-1045. doi:10.1016/j.cvsm.2023.04.005

 

What scientific evidence is there regarding the impact of breeding age on the health of breeding females?

Breeding age significantly influences reproductive outcomes. Breeding too early may reduce fertility (Concannon, 2011; Hollinshead et al., 2025), while breeding older females increases the risk of reproductive pathology, including pyometra and dystocia (Cornelius et al., 2019). Age-related hormonal exposure may also contribute to uterine changes that affect fertility (Camozzi et al., 2023; McRae et al., 2025). There is less peer-reviewed research on the risks of early breeding. Evidence from guide and assistance dog populations demonstrates that advancing maternal age is associated with reduced reproductive success, including declines in pregnancy rates, litter size, and serum anti-Müllerian hormone (AMH) concentrations, with particularly marked decreases observed after five years of age, especially in German Shepherds (Hollinshead et al., 2017).

  • Concannon, Patrick W. “Reproductive cycles of the domestic bitch.” Animal Reproduction Science, vol. 124, 3-4 (2011): 200-10. doi:10.1016/j.anireprosci.2010.08.028
  • Camozzi, Mylene G M et al. “Cystic endometrial hyperplasia-pyometra syndrome impairs the preantral follicle reserve in domestic bitches (Canis familiaris).” Reproductive biology vol. 23,4 (2023): 100813. doi:10.1016/j.repbio.2023.100813
  • Cornelius, Alyssa J et al. “Identifying risk factors for canine dystocia and stillbirths.” Theriogenology vol. 128 (2019): 201-206. doi:10.1016/j.theriogenology.2019.02.009
  • Hollinshead, F K et al. “Determination of the normal reference interval for anti-Müllerian hormone (AMH) in bitches and use of AMH as a potential predictor of litter size.” Reproduction in domestic animals = Zuchthygiene vol. 52 Suppl 2 (2017): 35-40. doi:10.1111/rda.12822
  • Hollinshead, Fiona & Sun, Xianfei & Aono, Michelle & Singletary, Melissa. (2025). Canine Puberty. The Veterinary Clinics of North America. Small animal practice. 55. 909-921. 10.1016/j.cvsm.2025.05.004.
  • McRae, Gail R et al. “Histological Studies in the Endometrium of Fertile and Subfertile Bitches.” Reproduction in domestic animals = Zuchthygiene vol. 60,4 (2025): e70055. doi:10.1111/rda.70055

 

What, if any, impact does the number and frequency of litters have on the health of female dogs? Are there studies evaluating the impact of breed size on the health and breeding of female dogs?

Because a bitch is a non-seasonal monestrous cycler, this means a bitch will cycle one to two times a year. Bitches have a long estrous cycle and require a long time (120 days) between cycles to have a fertile cycle. The bitch’s body is also really bad at telling them if they are pregnant or not. This is because during their cycle, the corpus luteum (CL) during diestrus (non-pregnancy) lasts around the same amount of time as the CL does if a bitch is pregnant (Concannon, 2011). This means the hormones the bitch experiences during her cycle are similar for both a pregnant and non-pregnant bitch (this is also why there is pseudocyesis in the bitch). With this prolonged exposure to hormones, bitches are more prone to pyometra if they are left unbred and not desexed. If a bitch has a normal cycle (over 120 days), has experienced no complications or delayed recovery from the previous cycle, and is in good health and appropriate body condition, breeding on consecutive cycles is not expected to have a significant negative impact on her health. Additionally, given the information presented, there may be a detriment to leaving a bitch not bred for extended periods of time while intact (Burns, G., 2023; Greer, M.L., 2015; Verstegen JP, et al., 2006).

ADI standards specify that breeding females should not be bred prior to 16 months of age, beyond six years of age, or for more than four litters. To support optimal welfare outcomes and identify factors that may necessitate earlier retirement, decisions regarding the timing of breeding retirement are made on a case-by-case basis. These determinations are guided by the individual dog’s health and welfare, the performance of related progeny, and programmatic needs. Consideration is also given to the total number of litters produced, with the expectation that a female’s final litter occurs prior to seven years of age (ADI, 2026).

  • Assistance Dogs International (2026). Compliance Guidance Notes 2026. https://assistancedogsinternational.org/clientuploads/Accreditation%20Documents/2026 /2026_Compliance_Guidance_Notes.pdf
  • Concannon, Patrick W. “Reproductive cycles of the domestic bitch.” Animal Reproduction Science, vol. 124, 3-4 (2011): 200-10. doi:10.1016/j.anireprosci.2010.08.028
  • Greer, M. L. (2015). Canine reproduction and neonatology: A practical guide for veterinarians, veterinary staff, and breeders. Teton NewMedia.
  • Burns, Greg. “All About the Brood”. Breeder’s Workshop 2023 Vancouver. International Working Dog Association, 2023. [Video]. https://www.youtube.com/watch?v=t8yKarS891w
  • Verstegen, JP and K. Onclin. “Prolactin and anti-prolactic agents in the pathophysiology and treatment of mammary tumors in the dog.” NAVC Proceedings, 2006. North American Veterinary Conference

 

What scientific evidence is there regarding the impact of heritable defects on the health of breeding females?

Inherited disorders in domestic dogs have been reported as long ago as the 19th century and include metabolic defects, sensory and neurological disorders, immunological conditions, blood disorders, and congenital physical deformities (Darwin, 1868; Hodgman, 1963). Dogs are second only to humans in the number of hereditary diseases identified in the species, and that number continues to increase (Bellumori et al., 2013). They fall into two broad categories: simple or single-gene disorders, caused by mutations in a single gene, or complex disorders, affected by multiple genes and environmental factors. There is a growing number of DNA tests available for known single-gene disorders in specific dog breeds, which allow breeders to avoid producing affected puppies. Breeding to avoid complex disorders is more complicated, but evidence-based screening schemes exist for some complex conditions, such as hip and elbow dysplasia.

It behooves breeders to avoid producing puppies affected by known inherited disorders by using DNA tests and health screening schemes where available. Information on inherited disorders of particular significance in a specific breed can be found from the American Kennel Club (AKC), breed clubs, and resources such as the Orthopedic Foundation for Animals (OFA) Canine Health Information Center (CHIC). ADI members must complete at a minimum genetic testing, hips, elbows, and heart screening of breeding candidates (ADI, 2026). They have a responsibility to optimize the health and welfare of dogs used for breeding. ADI and the IWDA provide educational resources to help member organizations identify which genetic testing and health screening they should undertake for their breeding dogs.

Considering direct effects on the health of breeding females, heritable musculoskeletal conditions such as hip dysplasia may be exacerbated by the female’s increased weight during pregnancy, as excessive body weight increases mechanical stress on joints, hastening the degenerative process (Harper, 2017). Bleeding disorders would also be a category for which direct effects on an affected female could be expected, and indeed, severe hemorrhage was reported in a pregnant Beagle with factor VII deficiency, which was presumed to be hereditary (Wheeler et al., 1984). Otherwise, there seems to be a paucity of scientific evidence to answer this specific question.

  • Assistance Dogs International (2026). Compliance Guidance Notes 2026. https://assistancedogsinternational.org/clientuploads/Accreditation%20Documents/2026 /2026_Compliance_Guidance_Notes.pdf
  • Bellumori, T.P., Famula, T.R., Bannasch, D.L., Belanger, J.M. and Oberbauer, A.M. Prevalence of inherited disorders among mixed-breed and purebred dogs: 27,254 cases (1995-2010) Journal of the American Veterinary Medical Association 242 (2013) 1549-1555
  • Darwin, C. The variation of animals and plants under domestication. J. Murray (1868)
  • Harper, T.A.M. Conservative management of hip dysplasia. Veterinary Clinics of North America Small Animal Practice 47 (2017) 807-821
  • Hodgman, S.F.J. Abnormalities and defects in pedigree dogs: 1. An investigation into the existence of abnormalities in pedigree dogs in the British Isles. Journal of Small Animal Practice 47 (1963) 184-188
  • Wheeler, S.L., Weingand, K.W., Thrall, M.A., Berg, R.J., Schwarz, and Olson, P.N. Persistent uterine and vaginal hemorrhage in a beagle with factor VII deficiency. Journal of the American Veterinary Medical Association 185 (1984) 447-448

 

What are the costs and benefits of genetic testing in breeding females for dog breeding facilities?

The primary costs to facilities are time and financial investment. While there are no direct “costs” to the dogs being tested, there may be meaningful benefits to both the individual and their offspring through the identification of health risks, enabling earlier diagnosis or preventative management. Genetic tests must be selected, ordered, and paid for; samples must be collected and submitted; and results require processing time. However, as DNA testing has become more widely available, costs have decreased, and many providers now offer cost-effective testing bundles tailored to specific breeds or user groups, including assistance dog organizations.

For private breeders, these costs may be partially offset by market demand, as prospective buyers are often willing to pay more for puppies with a lower risk of known breed-related genetic conditions (Voris et al., 2011). For assistance and working dog organizations, genetic testing is an integral component of selecting breeding stock, supporting the development of dogs that are more likely to remain healthy and successfully complete their working careers.

Another potential cost arises when a breeding candidate is deemed unsuitable based on health screening or DNA test results. While this may represent a short-term loss for a breeding program, it also provides clear health and welfare benefits for the individual dog and supports more responsible breeding decisions aligned with programmatic and ethical goals.

Together, these considerations underscore the key benefits of early disease detection and prevention, increased buyer confidence and willingness to invest in healthier puppies, and the broader ethical advantage of reducing the prevalence of heritable disorders within the population.

  • Voris, H.C., Wittum, T.E., Rajala-Schultz, P.J. and Lord,L.K. Characterization of advertisements for puppies sold online: Determinants of cost and a comparison with parent club breeders. Preventive Veterinary Medicine 100 (2011) 200-209

 

B. Socialization and Exercise of Dogs

Are there studies assessing the socialization needs of dogs, including interactions with humans and compatible dogs? Are there studies evaluating the effects of human interaction on the health and welfare of dogs in breeding facilities?

A substantial body of evidence demonstrates that early life environment, maternal care, and human interaction significantly influence behavioral, cognitive, and physiological outcomes in dogs. Early handling and enriched environments are associated with improved emotional stability and exploratory behavior (Gazzano et al., 2008; Majecka et al., 2020). Additionally, restrictive housing conditions and limited social interaction are associated with chronic stress, altered behavior, and reduced welfare (Beerda et al., 1999; Hubrecht et al., 1992; Hetts et al., 1992; Grigg et al., 2017; Hecker et al., 2024).

Puppies raised with limited human interaction in kennel settings were more likely to exhibit fear, aggression, and reduced ability to cope with novel situations (Majecka et al., 2020). Other studies found that restrictive or less stimulating environments negatively impact social behavior, stress responses, and engagement with humans (Hoof et al., 1999; Lenkei et al., 2019). Puppies exposed to more interactive and stimulating conditions, including handling and novel experiences, demonstrate better problem-solving skills and adaptability (Wright, 1983). Conversely, adverse or deprived early experiences are associated with increased fear, aggression, and stress-related behaviors later in life (Espinosa et al., 2025; Buttner and Strasser, 2022). Dogs from lower-quality or high-risk breeding environments, such as puppy farms or pet store sourcing, show higher rates of behavioral and health problems (Pirrone et al., 2016; Wauthier et al., 2018).

A recent study followed 59 Canine Companions (ADI Accredited Member) dams and litters raised either in private homes or in a professional facility during the first eight weeks postpartum. No significant differences in maternal care behavior were observed between environments, suggesting that appropriately managed professional rearing centers do not inherently compromise dam welfare and that puppies in both settings receive comparable early caregiving (Bray et al., in press). Maternal behavior plays a critical role in shaping stress responses and resilience. Variations in maternal care influence offspring cortisol regulation, fear responses, and adaptability (Nagasawa et al., 2014; Nagasawa et al., 2021; Tiira & Lohi, 2015).

The Bray et al. study also identified differences in puppy cognitive and behavioral outcomes, with each environment associated with strengths in different domains. Because neither setting was uniformly superior, these findings indicate that specific environmental features, rather than rearing location itself, likely shape developmental outcomes. The results support the use of evidence-based practices in both home and professional settings and suggest that targeted environmental and social exposures could help optimize development regardless of rearing location (Bray et al., in press).

It is recommended that any policy language drawing on these findings explicitly define what constitutes an “appropriately managed” professional facility. The research results above were obtained in the context of a well-resourced, professionally staffed facility with established welfare protocols, but the research itself cannot specify what those practices should be.

ADI standards are grounded in the principles reflected in the scientific literature on socialization, human interaction, and welfare outcomes in breeding populations. ADI requires that dogs are managed by individuals with appropriate expertise in reproduction, behavior, and welfare, ensuring informed oversight throughout the breeding cycle. Regular monitoring of both dams and puppies, combined with collaboration across breeding, training, and placement teams, supports the development of dogs suited for their future roles (ADI, 2026).

The standards also emphasize appropriate living conditions and handling practices that reduce stress, support maternal wellbeing, and promote positive human interaction. At the same time, ADI emphasizes biosecurity measures to minimize disease risk while still allowing for necessary social and environmental exposure (ADI, 2026).

  • Assistance Dogs International (2026). Compliance Guidance Notes 2026. https://assistancedogsinternational.org/clientuploads/Accreditation%20Documents/2026 /2026_Compliance_Guidance_Notes.pdf
  • Beerda, B, Schilder, MBH, Van Hooff, JARAM, De Vries, HW and Mol, JA. (1999) Chronic stress in dogs subjected to social and spatial restriction I: Behavioural responses. Physiology and Behaviour 66: 233–242
  • Bray, E.E., Douglas, L.E.L.C., Levy, K.M., Gnanadesikan, G.E.S., Horschler, D.J., Kennedy, B.S., & MacLean, E.L. (in press). Maternal care and early rearing environment influence puppy behaviour and cognition. Animal Behaviour. Preprint (peer-reviewed accepted version): https://www.biorxiv.org/content/10.64898/2025.11.29.691282v2
  • Buttner AP, Strasser R. Extreme life histories are associated with altered social behavior and cortisol levels in shelter dogs. Applied Animal Behaviour Science. 2022 Nov 1;256:105693.
  • Espinosa J, Zapata I, Alvarez CE, Serpell JA, Kukekova AV, Hecht EE. Influence of early life adversity and breed on aggression and fear in dogs. Scientific reports. 2025 Oct 2;15(1):32590.
  • Gazzano A, Mariti C, Notari L, Sighieri C, McBride EA. Effects of early gentling and early environment on emotional development of puppies. Applied Animal Behaviour Science. 2008 Apr 1;110(3-4):294-304.
  • Grigg, E.K., Nibblett, B.M., Robinson, J.Q. and Smits, J.E. (2017) Evaluating pair versus solitary housing in kennelled domestic dogs (Canis familiaris) using behaviour and hair cortisol: a pilot study. Vet Rec Open, 4: e000193. https://doi.org/10.1136/vetreco-2016-000193
  • Hecker G, Martineau K, Scheskie M, Hammerslough R, Feuerbacher EN. (2024) Effects of single- or pair-housing on the welfare of shelter dogs: Behavioral and physiological indicators. PLOS ONE 19(6): e0301137. https://doi.org/10.1371/journal.pone.0301137
  • Hetts, S.J. Derrell Clark, Janet P. Calpin, Cheryl E. Arnold and Jill M. Mateo. Influence of housing conditions on beagle behaviour, Applied Animal Behaviour Science, Volume 34, Issues 1–2, 1992, Pages 137-155, ISSN 0168-1591, https://doi.org/10.1016/S0168-1591(05)80063-2.
  • Hubrecht, RC, Serpell, JA and Poole, TB 1992 Correlates of pen size and housing conditions on the behaviour of kennelled dogs. Applied Animal Behaviour Science 34: 365–383
  • Majecka K, Pąsiek M, Pietraszewski D, Smith C. Behavioural outcomes of housing for domestic dog puppies (Canis lupus familiaris). Applied Animal Behaviour Science. 2020 Jan 1;222:104899.
  • Nagasawa M, Shibata Y, Yonezawa A, Takahashi T, Kanai M, Ohtsuka H, Suenaga Y, Yabana Y, Mogi K, Kikusui T. Basal cortisol concentrations related to maternal behavior during puppy development predict post-growth resilience in dogs. Hormones and behavior. 2021 Nov 1;136:105055.
  • Pirrone F, Pierantoni L, Pastorino GQ, Albertini M. Owner-reported aggressive behavior towards familiar people may be a more prominent occurrence in pet shop-traded dogs. Journal of Veterinary Behavior. 2016 Jan 1;11:13-7.
  • Tiira K, Lohi H. Early life experiences and exercise associated with canine anxieties. PloS one. 2015 Nov 3;10(11):e0141907.
  • Wauthier LM, Williams JM. Using the mini C-BARQ to investigate the effects of puppy farming on dog behaviour. Applied Animal Behaviour Science. 2018 Sep 1;206:75-86.
  • Wright, J.C. The effects of differential rearing on exploratory behavior in puppies. Appl. Anim. Ethol. 1983;10: 27-34.

 

Are there studies assessing the health and well-being of singly housed dogs?

Multiple studies have directly evaluated the welfare of singly housed dogs using both behavioral and physiological indicators and have consistently shown negative impacts compared to social housing.

Experimental and observational studies demonstrate that social and spatial restriction, conditions analogous to single housing, are associated with chronic stress, including increased stress-related behaviors and elevated cortisol with immune suppression (Beerda et al., 1999a; Beerda et al., 1999b). Additional studies report higher levels of abnormal or inactive behavior in individually housed dogs compared to those housed socially or in enriched environments (Hetts et al., 1992; Hubrecht et al., 1992; Mertens & Unshelm, 1996).

More recent research further supports these findings, showing that pair- or group-housed compatible dogs exhibit improved welfare outcomes, including reduced stress-related behaviors and lower physiological stress markers (Grigg et al., 2017; Hecker et al., 2024).

Overall, the available evidence indicates that single housing is associated with poorer behavioral and physiological welfare outcomes, while social housing with compatible dogs provides measurable welfare benefits. However, individual differences must be considered when making housing decisions, and single housing may be an appropriate management tool to support welfare in specific cases, especially for breeding dogs, biosecurity, and neonatal care.

ADI’s standards state that welfare for kenneled dogs of all life stages focuses on providing a clean, comfortable, and safe environment that supports both physical and psychological well-being, including appropriate kennel size, ventilation, lighting, and protection from extreme weather. It also emphasizes environmental enrichment, such as toys, social interaction, and sensory stimulation, to reduce stress and promote natural behaviors, with overall practices guided by the Five Domains model to ensure dogs’ nutritional, environmental, health, behavioral, and mental needs are met (ADI, 2026).

  • Assistance Dogs International (2026). Compliance Guidance Notes 2026. https://assistancedogsinternational.org/clientuploads/Accreditation%20Documents/2026 /2026_Compliance_Guidance_Notes.pdf
  • Beerda, B, Schilder, MBH, Van Hooff, JARAM, De Vries, HW and Mol, JA. (1999) Chronic stress in dogs subjected to social and spatial restriction I: Behavioural responses. Physiology and Behaviour 66: 233–242
  • Beerda, B, Matthijs B.H Schilder, Wilbert Bernadina, JAN A.R.A.M Van Hooff, Hans W De Vries and Jan A Mol. Chronic Stress in Dogs Subjected to Social and Spatial Restriction II: Hormonal and Immunological Responses, Physiology & Behavior, Volume 66, Issue 2, 1999, Pages 243-254, ISSN 0031-9384, https://doi.org/10.1016/S0031-9384(98)00290-X.
  • Grigg, E.K., Nibblett, B.M., Robinson, J.Q. and Smits, J.E. (2017), Evaluating pair versus solitary housing in kennelled domestic dogs (Canis familiaris) using behaviour and hair cortisol: a pilot study. Vet Rec Open, 4: e000193. https://doi.org/10.1136/vetreco-2016-000193
  • Hecker G, Martineau K, Scheskie M, Hammerslough R, Feuerbacher EN. (2024) Effects of single- or pair-housing on the welfare of shelter dogs: Behavioral and physiological indicators. PLOS ONE 19(6): e0301137. https://doi.org/10.1371/journal.pone.0301137
  • Hetts, S.J. Derrell Clark, Janet P. Calpin, Cheryl E. Arnold, Jill M. Mateo, Influence of housing conditions on beagle behaviour, Applied Animal Behaviour Science, Volume 34, Issues 1–2, 1992, Pages 137-155, ISSN 0168-1591, https://doi.org/10.1016/S0168-1591(05)80063-2.
  • Hubrecht, RC, Serpell, JA and Poole, TB. (1992) Correlates of pen size and housing conditions on the behaviour of kennelled dogs. Applied Animal Behaviour Science 34: 365–383
  • Mertens, P. A., & Unshelm, J. (1996). Effects of Group and Individual Housing on the Behavior of Kennelled Dogs in Animal Shelters. Anthrozoös, 9(1), 40–51. https://doi.org/10.2752/089279396787001662

 

What scientific information is available regarding the exercise needs of dogs, including considerations of the animal’s age, breed, and health, the type of exercise, and exercise frequency and duration?

Available scientific literature supports that regular exercise is a critical component of canine welfare, contributing to physical health, weight management, behavioral stability, and mental well-being (Farr et al., 2020; Caspersen et al, 1985). However, the research does not establish universally prescriptive standards for exact exercise duration, frequency, or type across all dogs. Instead, it consistently emphasizes variability based on individual factors rather than fixed thresholds (Farr et al., 2020).

Key considerations identified in the literature include age, breed/type, health status, and physiological condition. For example, younger and more active dogs generally require higher levels of physical and cognitive engagement, while senior dogs benefit from lower-impact, shorter-duration activity to support mobility and reduce risk of injury. Health conditions, including orthopedic concerns, obesity, and reproductive status (e.g., pregnancy and lactation), also necessitate tailored adjustments in exercise intensity and structure (Farr et al., 2020).

Effective exercise performance in dogs relies on coordinated physiological systems to deliver oxygen to working muscles, alongside an intact musculoskeletal system; disruption to these systems may result in lameness, defined as asymmetric limb use due to injury affecting muscles, bones, joints, or nerves (Otto et al., 2019).

The research further highlights that exercise extends beyond physical exertion alone. Opportunities for exploratory behavior, such as sniffing and environmental interaction, along with play and training activities, are important contributors to mental stimulation and overall welfare (Farr et al., 2020).

In summary, the scientific evidence supports a flexible, individualized approach to exercise, one that adjusts type, intensity, frequency, and duration based on the dog’s specific characteristics, rather than rigid, one-size-fits-all requirements. This aligns with a welfare-focused application of current science and provides a practical basis for adaptable guidance across diverse canine populations (Farr et al., 2020).

  • Farr BD, Ramos MT and Otto CM. (2020) The Penn Vet Working Dog Center Fit to Work Program: A Formalized Method for Assessing and Developing Foundational Canine Physical Fitness. Front. Vet. Sci. 7:470. doi: 10.3389/fvets.2020.00470
  • Caspersen CJ, Powell KE and Christenson GM. Physical activity, exercise, and physical fitness: definitions and distinctions for health-related research. Public Health Rep. 1985 Mar-Apr;100(2):126-31. PMID: 3920711; PMCID: PMC1424733.
  • Otto CM, Cobb ML and Wilsson E. (2019) Editorial: Working Dogs: Form and Function. Front. Vet. Sci. 6:351. doi: 10.3389/fvets.2019.00351

 

3. Regulatory Alignment and Consideration of Practical Impacts on Established Programs

ADI-accredited organizations operate within rigorous, internationally recognized frameworks while also navigating complex state and federal regulatory environments.

As the USDA considers updates to federal requirements, there is a meaningful opportunity to align regulatory approaches with both peer-reviewed scientific evidence and the demonstrated outcomes of established programs.

These programs are built on decades of data collection, continuous evaluation, and application of canine developmental science. At the same time, gaps remain in the peer-reviewed literature in certain areas of breeding and rearing practices. In these instances, established standards—such as those developed by ADI—reflect outcome-based practices that may serve as a valuable complement to the scientific evidence base.

Given this, it is important that regulatory development include direct engagement with organizations actively implementing these practices. Ensuring that subject matter experts and accredited programs have a “seat at the table” will support the development of policies that are both scientifically grounded and practically feasible.

Consideration should also be given to the operational realities of established assistance and working dog programs. Highly prescriptive or inflexible requirements may unintentionally limit the ability to apply individualized, evidence-based approaches, particularly in areas such as early development, socialization, and breeding management, where timing and responsiveness to animal-specific needs are critical.

A collaborative regulatory approach could include:

  • Prioritizing peer-reviewed scientific evidence as the foundation for regulatory standards, while recognizing areas where applied, outcome-based practices provide additional insight
  • Establishing pathways for exceptions, flexibility, or equivalency for ADI-accredited programs that demonstrably meet or exceed welfare benchmarks
  • Aligning federal requirements, where appropriate, with existing international accreditation frameworks to reduce redundancy and conflict and to increase collaboration and adoption of best practices
  • Engaging accredited organizations and scientific experts throughout the rulemaking process to inform implementation considerations

Such an approach would support regulatory updates that advance canine welfare in a thoughtful, evidence-based manner, integrating scientific knowledge with practical, real-world expertise.

Thank you for your consideration of our comments and your commitment to advancing canine welfare. Please do not hesitate to reach out to ADI with any questions about these comments or for further information about the topics covered in the RFI.

Sincerely,

David Locklin
Executive Director, Assistance Dogs International

Dr. Karen Overall, MA, VMD, PhD, DACVB
President, International Working Dog Association Board of Directors

Dr. Gail McRae, DVM, MS, DACT
Assistant Director of Canine Health & Reproduction at Leader Dogs for the Blind

Dr. Katy Evans, BVSc MSc PhD CertVA MRCVS
The Jane H. Booker Chair in Canine Genetics & Animal Welfare Lead at The Seeing Eye

Dr. Kelly Mann, DVM, MS, MSS, DACVR
Vice President, Veterinary Solutions, Mantel Technologies; Affiliate faculty, Department of Clinical Sciences, Colorado State University; Vice President, IWDA Board of Directors

Dana Hunter, BS, CNWI
ADI – International Breeding Cooperative Facilitator

Rachel Goldammer, BS
Consultant, International Working Dog Association