By: Robert Hubrecht PhD CBiol FIBiol
Deputy (Scientific) Director
Universities Federation for Animal Welfare (UFAW)
The Old School
Data from archaeology and molecular studies indicate that dogs have been
domesticated for at least 14,000 years, and possibly much longer (Clutton-Brock, 1995; Vila
et al., 1997), and thus were amongst the first domesticated animals. The dog’s ancestor is
generally considered to be the wolf (Jackson, 1994) although it has been argued that the
lineage was separate with occasional interbreeding with wolves (Koler-Matznick, 2002).
Certainly, dog-wolf offspring can still be fertile (Alderton, 1994). The long period of
domestication has provided ample opportunity for humans to select for the enormous variation
in physical and behavioral traits, greater than that seen in any other domesticated species
(Asdell, 1966), that we now see in the domestic dog. Early breed selection was probably for
hunting and guarding, as well as some propensity to interact well with humans. However,
dogs have been bred for many other traits including herding, haulage, companionship, and
the ability to provide assistance (e.g. guide dogs, hearing dogs, and dogs for the disabled).
Some dogs now have a highly developed ability to interpret human signals, and can even imitate,
thus mapping another’s behavior on to itself (Tópal et al., 2006).
Sadly, selection for desired traits has led to the development of breed defects. These can arise as a direct result of the trait being selected for (e.g. respiratory problems in brachycephalic dogs), or through inadvertent selection for harmful genes that may be closely linked to the gene coding for the desired trait. Naturally, breeders want offspring to breed true, and so animals have often been inbred with the undesired consequence of concentrating deleterious genes within a breed population. The result is that most breeds have a range of inherited defects (an online database http://omia.angis.org.au/ lists 481 genes, inherited disorders and traits for the dog) some of which may have an unacceptably high incidence, but which could be reduced by appropriate screening and breeding programs (McGreevy and Nicholas, 1999; CAWC, 2006). It has been suggested that domestication has, at least partly, involved selection for juvenile characteristics (for example, increased dependence, propensity to bark) and that this has resulted in the domestic dog becoming neotenized. Some breeds have clearly been selected specifically for infantile looks, and it is interesting to note that breeds that look most different from the ancestral type have experienced greater loss of their ability to express behavioral signals (Goodwin et al., 1977). While it is conceivable that these breeds might have greater difficulty interacting in a group, the welfare consequences have not been researched.
Stray and feral dogs
Major welfare problems for companion dogs are that many stray, and huge numbers each year are abandoned. Behavior problems are commonly given as reasons for giving up animals to rescue organizations and to address these there is a growing industry of dog behavior consultants; some of whom are beginning to use their experience in behavior modification to advise on the training or behavior of dogs used in research. Abandoned or stray dogs may experience malnutrition, injury, illness or death. According to the HSUS website (HSUS, 2007) between six and eight million dogs and cats enter U.S. shelters every year and three to four million of these animals are euthanized because there are not enough homes for them. There is continuing research on temperament tests to match dogs with potential new owners. In some countries dogs are taken from pounds and used by research establishments, although this is not legal within Europe. It could be argued that using pound dogs is ethically preferable to destroying them, which then necessitates breeding others for research, however, the JWGR (2004) provides a number of good reasons (health, safety, public confidence, etc) why purpose breeding is preferable.
Housing and Husbandry
Dogs are kept in kennels by a variety of organizations. Examples include: rescue organizations, hunt kennels, quarantine kennels, boarding kennels, police, and assistance organizations. In addition dogs (mainly beagles) are bred and kept in kennels for biomedical research and for nutritional studies. A useful general source of information for housing and care of laboratory dogs is (MacArthur Clark, 1999). Traditionally kennels were often small, designed to house one dog, and were often devoid of anything to occupy the dog or provide variety. Such environments resulted in timid fearful dogs or dogs with repetitive behavior disorders such as stereotypies, or self injuring behavior. Studies in both shelters and research establishments have shown that the longer dogs spend in sub-optimal environments, the more likely they are to show abnormal or undesirable behaviors (Hubrecht, 1995; Wells et al., 2002). These dogs are likely to make poor research subjects; moreover, since dogs may spend considerable periods in kennels the welfare impact can be considerable. Over the last 15 years or so, there have been some important changes in the conditions considered acceptable for the breeding and keeping dogs used in research and these have also influenced standards for other types of kenneling. There are several recent documents that provide comprehensive reviews and recommendations based on applied research and the natural history of the dog (Hubrecht and Buckwell, 2004; JWGR, 2004; Council of Europe, 2006). Of these, the JWGR (2004) is a particularly useful document as it covers an extremely wide range of topics through breeding, transport, procedures and ultimate destiny of the dog. Many of the principles outlined in these documents have been successfully incorporated into research facilities (e.g. Ottesen et al., 2004) and have resulted in notable behavioural improvements.
One of the most important changes in the kennelling of research dogs has been in the reduction of single housing. For many years social housing has been the default system in the UK. In the UK minimum enclosure dimensions are sufficient to house one or two dogs, therefore making pair housing financially advantageous. A similar strategy has now been adopted in the recent revision of Council of Europe recommendations (Council of Europe, 2006), and social housing is becoming ever more widely accepted throughout the research community. Even where dogs have to be isolated during dosing in regulatory studies, or feeding during nutritional studies, dogs can still be housed in pairs or groups for the rest of the time. Bayne (2003) notes “In Europe, it is common for dogs on GLP toxicology studies to be socially housed, but separate them for feeding so food consumption can be better measured. This trend is less common, however, in the United States”. Nonetheless, (Mack et al., 2003) have shown that it can be done, and as UK companies have to comply with either the same or similar regulatory requirements, a more general adoption of social housing would seem to be a relatively easy gain to be made in the USA. Good kennel design is critical in allowing the adoption of social housing and modular designs, allowing animals to be run together as desired, are a useful flexible means of achieving this. Social housing does bring an increased risk of injury, however, and husbandry regimes should be designed to monitor aggression (Hubrecht and Buckwell, 2004).
Exercise, human contact, socialization, and training
Some dogs clearly enjoy exercise, but when companion animals are exercised they also experience exploration, territory marking and socializations all of which are likely to add to the hedonistic experience of the activity. Hence, in the research setting the benefits of exercise periods will, to a large extent, depend on the exploratory and social opportunities offered to the dogs. Depending on how dogs have been socialized, human contact can be very important for them but providing sufficient human contact in kennels can be a serious difficulty. Often less than an hour a day is feasible, but even 45 minutes has been shown to be beneficial (e.g. for shelter dogs Coppola et al., 2006). Dogs used in research can be trained to cooperate with husbandry and research procedures (Boxall et al., 2004). The dogs are given more human contact time and are less nervous, which is good for their welfare; and they are more cooperative and easier to handle which is good for the staff and researcher. Accustoming the animal to situations or handling techniques that it will meet later in life can be done at the breeding facility but requires good communication between the researcher and the breeding establishment.
Compared to primates and rodents, there have been rather few studies on non-social enrichment for dogs. Those studies that have been carried out (reviewed with social enrichment in Wells, 2004 and JWGR, 2004) emphasize the importance of providing chews, platforms, visual sight lines and complexity and of designing enrichment strategies with the dogs natural behavior and sensory modalities in mind. Unfortunately, there have been very few studies on auditory or olfactory enrichment which is a glaring omission given the importance of these senses to the dog. A subject of some interest, however, has been the use of dog appeasement pheromone (DAP) as a means of reducing the stress of dogs when placed in unfamiliar circumstances. This has been tested on dogs taken to veterinary surgeries, and in shelters (e.g. Tod et al., 2005).
Nutrition and health and behavior
Many dogs are highly motivated by food (chews that taste of food seem to be preferred by dogs), and a study reported in Houpt and Zicker (2003) estimated that 24-30% of adult American dogs were overweight, with concomitant health risks of musculoskeletal, cardiovascular problems and diabetes. Conversely, many stray dogs suffer from malnutrition, which, if experienced during development, can lead to behavioral as well as physical abnormalities. Much attention is given by pet food manufacturers to ensuring that their diets are palatable, as owners are often influenced in their purchasing decisions by their dog’s reaction to food. Much less attention seems to have been given to commercial laboratory diets, however, as very palatable diets can increase the risk of aggression in kennels (Coppinger and Zucotti, 1999) this may have helped the move toward social housing. In an aging society, links between diet and cognition and behavior are of increased interest, and dogs have been used in studies on the effects of diet on behavior and cognitive function as a model of human degenerative disorders as well as to study the effects of diet on companion animals (see Houpt and Zicker, 2003; Zicker, 2005).
Dogs are capable of generating a great deal of noise. This can be a potential health problem for humans working in kennels, and given the greater sensitivity of dogs to sound, may be a welfare issue for the dogs themselves (Sales et al., 1997; Coppola et al., 2006). Buildings and husbandry routines should be designed so as to reduce noise. A study of shelter dogs has shown that group housing is associated with a significant reduction in noise production (Mertens and Unshelm, 1996), which could well be a significant benefit in the research setting.
Detection of stress, distress and pain relief
Refinement of procedures is dependent on detecting signs of stress, distress and pain. Institutions should ensure that staff are trained in these skills (JWGR, 2004) and Beerda et al., 2000) provides a number of indicators of chronic and acute stress. Post-operative analgesia is now routine for research animals (see Flecknell, 1997). There is growing interest in research into alleviating pain for companion dogs (Hansen, 2003), and this provides a body of research and experience to the research scientist working with dogs that is not available for some other species.
The topics covered in this introduction have necessarily been dealt with briefly. The linked bibliography provides both further information on dog welfare (for example information on anaesthesia, analgesia and health) and also a wealth of information pertaining to practical issues such as breeding, the use of dogs in research and zoonoses. Staff caring for dogs, whether in rescue shelters, quarantine kennels, working dog kennels, boarding kennels or research establishments, as well as those intending to use them in research have an ethical obligation to understand their needs and to meet these as far as possible. This bibliography is an extremely useful resource that will help them towards this goal.
Alderton, D. (1994). Foxes, Wolves and Wild Dogs of the World. Facts on File: NY, NY, 192p.
Asdell, S.A. (1966). Dog Breeding: Reproduction and Genetics. J and A Churchill Limited: London, UK, 194 p.
Bayne, KA.L. (2003). Environmental Enrichment of Nonhuman Primates, Dogs and Rabbits Used in Toxicology Studies. Toxicologic Pathology 31:1, 132-137.
Beerda, B., M.B.H. Schilder, J.A.R.A.M. van Hooff, H.W. de Vries, and J.A. Mol (2000). Behavioural and hormonal indicators of enduring environmental stress in dogs. Animal Welfare 9: 49-62.
Boxall, J., S. Heath, S. Bate, and J. Brautigam (2004). Modern concepts of socialisation for dogs: Implications for their behaviour, welfare and use in scientific procedures ATLA 32(Supplement.2): 81-93.
CAWC (2006) Breeding and Welfare in Companion Animals: The Companion Animal Welfare Council's Report on Welfare Aspects of Modifications, through Selective Breeding or Biotechnological Methods, to the Form, Function, or Behaviour of Companion Animals http://www.cawc.org.uk/
Clutton-Brock, J. (1995) Origins of the dog: domestication and early history. In: The Domestic Dog: Evolution, Behaviour, and Interactions with People. J Serpell (ed), Cambridge University Press: Cambridge, pp. 7-20.
Coppinger, R. and J. Zucotti (1999) Kennel enrichment: Exercise and socialization of dogs. Journal of Applied Animal Welfare Science 2(4) 281-296
Coppola, C.L., M.R.. Enns and T. Grandin (2006) Noise in the Animal Shelter Environment: Building Design and the Effects of Daily Noise Exposure. Journal of Applied Animal Welfare Science 9: 1-7
Coppola, C.L., T. Grandin, and R.M. Enns (2006). Human interaction and cortisol: can human contact reduce stress for shelter dogs? Physiology and Behavior 87(3): 537-41.
Council of Europe (2006). Appendix A guidelines for accommodation and care of animals (adopted version). Background information on the draft proposal for species-specific provisions for dogs presented by the Group of Experts. http://www.coe.int/t/e/legal_affairs/legal_cooperation/biological_safety,_use_of_
animals/laboratory_animals/Revision of Appendix A.asp#TopOfPage
Flecknell, P. (1997). Assessment and alleviation of post-operative pain. Animal Welfare Information Center Newsletter. 8(3/4): 8-14.
Goodwin D., J.W.S Bradshaw, and S.M. Wickens (1997). Paedomorphosis affects agonistic visual signals of domestic dogs. Animal Behaviour 53: 297-304.
Hansen, B.D. (2003). Assessment of pain in dogs: Veterinary clinical studies. ILAR Journal 44(3): 197-205.
Houpt, K.A. and S. Zicker (2003) Dietary effects on canine and feline behavior Veterinary Clinics of North America: Small Animal Practice 33(2): 405-416.
Hubrecht, R.C. (1995). Enrichment in puppyhood and its effects on later behaviour of dogs. Laboratory Animal Science 45: 70-75
Hubrecht, R.C. and A. Buckwell (2004) The Welfare of Laboratory Dogs. In: The Welfare of Laboratory Animals, Kaliste, E. (ed.), Kluwer Academic Publishers: Doordrecht/Boston/London, pp 245-273.
HSUS (2007) Website May 23rd http://www.hsus.org/pets/issues_affecting_our_pets/pet_overpopulation_and
JWGR (2004) BVAAWF/FRAME/RSPCA/UFAW Joint Working Group on Refinement 2004. Refining Dog Husbandry and Care. Eighth report of BVAAWF/FRAME/RSPCA/UFAW Joint Working Group on Refinement. Laboratory Animals 38(Suppl 1): 1-94. http://www.lal.org.uk/index.php/component/docman/doc_download/26-dogworkingpartypdf
Koler-Matznick, J. (2002). The origin of the dog revisited. Anthrozoos 15:98-118
Mack, P.A., R.M. Bell, B.L. Tubo, J.A. Ashline, and K.L. Smiler (2003). Validation study of social housing of canines in toxicology studies. Contemporary Topics in Laboratory Animal Science 42(2): 29-30.
MacArthur, J.A. (1999) The Dog. In: The UFAW Handbook on the Care and Management of Laboratory Animals, T. Poole (ed.), Volume 1, 7th ed., Blackwell Science Ltd, London, pp. 423-444.
McGreevy, P.D. and F.W. Nicholas (1999). Some practical solutions to welfare
problems in dog breeding. Animal Welfare 8, 329-341.
Mertens, P.A. and J. Unshelm (1996). Effects of group and individual housing on the behavior of kennelled dogs in animal shelters. Anthrozoos 9(1): 40-51
Ottesen, J.L., A. Weber, H. Gurtler, and L.F. Mikkelsen (2004). New housing conditions: improving the welfare of experimental animals. ATLA Alternatives to Laboratory Animals 32(Suppl. 1B): 397-404. ISSN: 0261-1929.
Sales G, R. Hubrecht, A. Peyvandi, S. Milligan and B. Shields (1997). Noise in dog kennelling: Is barking a welfare problem for dogs? Applied Animal Behaviour Science 52: 321-329.
Tod, E., D. Brander, N. Waran (2005). Efficacy of dog appeasing pheromone in reducing stress and fear related behaviour in shelter dogs Applied Animal Behaviour Science 93(3-4): 295-308
Topal, J., R.W. Byrne, A. Miklosi, and V. Csanyi (2006). Reproducing human actions and action sequences: ''Do as I Do!'' in a dog Animal Cognition 9: 4 (OCT) 355-367
Vila, C, P. Savolainen, J.E. Maldonada, I.R. Amorim, J.E. Rice, R.L. Honeycutt, K.A. Crandall, J. Lundeberg, and R.K. Wayne (1997). Multiple and ancient origins of the domestic dog. Science 276:1687-1689
Wells, D.L., L. Graham, P.G. Hepper (2002). The influence of length of time in a rescue shelter on the behaviour of kennelled dogs Animal Welfare 11: 3, 317-325.
Wells, D.L. (2004). A review of environmental enrichment for kennelled dogs, Canis familiaris. Applied Animal Behaviour Science 85(3-4): 307-317.
Zicker, S.C. (2005). Cognitive and behavioral assessment in dogs and pet food market applications. Progress in Neuro-Psychopharmacology and Biological Psychiatry 29(3): 455-459.