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Throughout the centuries pets have been kept for companionship, security and working or hunting (especially dogs, birds e.g. hawks, and ferrets for hunting). Pets have continued to be kept for their usefulness to humans and to fulfill personal needs in spite of any adverse effects on their health.
The incidences of pet-related zoonoses transmitted from pets to humans depends on a number of factors (Stehr-Green and Schantz, 1987), including:
These factors will differ with each pathogen, location, family and pet, with children and other groups that have closer physical contact with animals, (see discussion on pets of Indigenous people) tending to be at higher risk of infection.
Stehr-Green and Schantz (1987) summarize transmission modes and the incidences and costs of zoonotic diseases associated with pets. Organisms are grouped according to their identification as helminthes (worms), protozoa, bacteria, fungi, viruses and arthropods.
Diseases most prevalent and therefore well known to the public are:
Popular assumptions about the role of fecal litter and zoonotic infections are often misleading. Many councils and environmental groups believe that most of the fecal pollution occurring in Australia’s coastal rivers and lakes is attributable to pets. A recent CSIRO study refutes this however, finding that native birds contribute up to 90% and pets only 8-19% in six sites tested (Murray and Penridge, 1997). More efficient excrement disposal is suggested for high-density and multi-dwelling developments by the installation of a communal disposal unit for feces (PIAS, 1993). To eliminate the problem of feces in public places (one of the main reasons for banning dogs in public places) the following suggestions have been made:
More than 60 zoonotic diseases have been reported in Australia and New Zealand with only a small proportion of these associated with pets. Normal immunity provides effective protection from disease in most cases, so that zoonotic diseases are not even mentioned in the 1994 Australian Bureau of Statistic’s figures for principal causes of death.
Other human health threats are through dogs and cats causing traffic accidents, but of greater concern is damage to health through dog attacks on people. Dog and cat bites accounted for 2% of all injuries in one national survey, with children and older people being at risk. A 1991 study in Adelaide (Thompson, 1991) showed that most dog attacks were not by stray or strange dogs in public areas but were made by dogs of family members or friends. Bites are the most common injuries and although there were no deaths recorded due to dog bite in the 1980s in Australia, there have been more than 5 fatalities in the 1990s, thought to be due to the increasing trend towards ownership of larger more aggressive (male) dogs.
The barking of dogs has been shown to have an adverse effect on peoples’ physical and mental health. (Bell et al., 1978). A survey in Townsville showed that barking was the most common dog problem and people rated dog barking as more annoying than traffic noise (Murray 1991). Stress arises due to the volume of noise, unpredictability and the lack of control of the noise from a barking dog that is not your own. Much advice is available on training dogs out of excessive barking, including:
White people often see the dogs of Indigenous people as starved, diseased and mangy compared with their own dogs. To understand dog health and human health in Aboriginal communities, appreciation of the historical context is needed. Before Europeans arrived in Australia, dingoes, introduced into Australia by Asian seafarers, were used by Aborigines for companions, hunting aides and protectors (Wilks and Williamson, 1998). Only partial domestication of the dingo occurred with dingoes often foraging for their own food. It was thought that the interest in the dingo may have been because it was a hunter and the only animal to give birth in the same way as humans, all other Australian mammals at that time being marsupials or monotremes. After the arrival of Europeans, domestic dogs replaced dingoes with the following problems:
The modern community Aborigine still keeps dogs for companions, hunting aides and protection and in some communities e.g. Arukan, there is still the belief that ‘spirit dogs’ embody the spirits of the deceased. Harsh treatment of Aborigines by white police in past times involved punishing Aborigines by shooting their dogs (Arden, 1995).
Today the potential for transmission of canine disease to humans is very high in Aboriginal communities. This can be attributed to the health of dogs suffering due to overcrowding and the difficulty in feeding large numbers of dogs. When Aborigines were living in a nomadic lifestyle, population regulation of dingoes took place by the capture of puppies from the wild without breeding occurring within camps. Dingoes also foraged for their own food whereas the European dog relied on the Aborigines for food. The rapid transition of Aboriginal people from a nomadic lifestyle to a permanent place of abode resulted not only in crowding of people but also of their animals. There is an illusion that Aboriginal communities have a very high dog population but dog counts (Shield, 1992) for the Aboriginal community at Cape York is one dog per 5 people, very similar to that for the whole of Queensland (1:6). The fact that there may be several dog owners living at the same property also contributes to the illusion of the very high dog population for Aboriginal people (Wilks and Williamson, 1998).
However the close association between dogs and humans in an Aboriginal community where beds may be shared with dogs and fecal disposal is often a problem (Ross, 1987) raises concern that hookworm, roundworm, tapeworm and mange could be passed from dogs to the Aboriginal people. It is a concern for northern animals for their proximity to PNG and Indonesia where rabies and screwworm flies are endemic.
Over the last ten years there have been several programs that have aimed to improve the health of dogs in Indigenous communities and as a result, to improve the health of the people in those communities. Indigenous communities are often very isolated from veterinary services and so programs were designed for vets to visit communities on a regular basis thus giving the people better access to advice and health care for their dogs.
In 1989 the Queensland DPI Aboriginal Dog Health Program was commenced for the Aboriginal and Islander population of Cape York in Northern Queensland (Shield, 1992). It aimed to:
This Program has been very successful in improving the health of the dogs and reducing dog populations. There are no quantitative results but there is anecdotal evidence of an improvement in human health (Shield, 1992). It was emphasized that the success of this program was due to the fact that it was in response to appeals for help from the Aboriginal communities themselves and not something imposed on them from outside.
In 1992, the “Dog Health Program in Aboriginal Communities” was introduced into 14 Aboriginal communities in the Kimberleys (Wilks and Williamson, 1998). Its aims were to:
Dogs from each community were identified using a microchip system. Dogs were seen every 3 months for the 3.5 years of the program. Fecal samples, blood samples and skin scrapings were collected from the dogs, information regarding reproductive status was record and dogs were treated with an anti-parasitic injection. Mature female dogs, at the owner’s request were given an injection for control of estrus. Initially 99% of dogs were brought back for their next visit and this had decreased but still stayed at 81% at the end of the pilot program.
Results showed:
The pilot program has expended from 14 communities to over 50 communities in the Kimberley and Pilbara regions of Western Australia. Programs in communities are now managed and operated by community people and supervisors from Public Health Units of the Health Department of WA and local shires of the two regions. Its success is due to the fact that it has removed some of the antagonism toward the Aboriginal person-dog relationship that was brought about by the WA Dog Act of 1902-1965. This act restricted Aboriginal people to owning only one dog, which had to be male and kept free from disease and registered, much tougher laws than were in place for white people at that time. This new program ensures that dogs are registered as they enter the program and addresses the concerns of zoonotic disease as well as offering acceptable population control rather than the culling of dogs. It gives power to the communities to choose the services it wants and promotes collaboration between health workers and the shire, giving the potential for further education programs to be established.
Currently the ‘Mr. Germ’ program being run by the Indigenous Public Health in Townsville, is encouraging Indigenous people to remove their dogs from their homes at night time and to wash their hands thoroughly to prevent disease transmission.
There is growing evidence that pets can improve the health of their owners. For many years there has been a huge amount written on this subject, but until the last few years there has been little hard, scientific evidence for this.
Health benefits can be considered under the following areas:
In 1980 it was shown (Friedman et al., 1982) that there was a better survival rate in pet owners recovering from coronary bypass operations than in non-pet owners.
In 1983 the relaxing effect of watching fish in an aquarium at a dentist was measured and documented using blood pressure and observation of relaxation criteria (Friedman et al., 1983).
In Australia it has been shown that pet-owners have lower levels for plasma triglycerides, circulating cholesterol and systolic blood pressure (Anderson et al., 1992). Although there was not a causative nature between these factors and pet ownership, it has been reported that pet owners, particularly dog owners, are more physically active than the rest of the population.
It has been estimated that because pet owners see their doctors less often, the reduction in visits to GPs could be saving Australia between $790 million and $1.5 billion annually (Headey et al., 1995)
The following programs are of enormous benefit to people with health disabilities:
These are only some of the ways in which pets have been thought to positively influence the physical and mental health of humans. It is thought that these beneficial effects could arise though pets distracting our attention from our own situation, pets being good listeners without questioning or evaluating, pets providing companionship especially in our present day society with its increasing isolation of different age groups, and from the sense of responsibility involved in caring for animals. (Vine, 1993).
There appear to be diametrically opposed positions on the issue of pets and public health. One group believes that pets may be hazardous to your health (Hubert, 1984) whilst on the other hand it is felt that there are both health and economic benefits associated with pet ownership (Australian Companion Animal Council, 1995). To address both positions successfully involves identifying the conflicting interests and working a pathway towards a compromise position (Murray and Penridge, 1997). This can be done through Municipal Pet Management Programs (MPM) carried out by Pet Management Officers (PMO). The ‘Car’ paradigm (Murray and Penridge, 1997) illustrates an ownership method involving infrastructure, administration, education, and regulation which is pragmatic and reasonable.
Whilst these methods are succeeding in urban areas, it must be recognized that there may be certain groups of people (e.g. Indigenous) in certain situations (e.g. rural and remote areas with little access to vets or help from Public Health officials) for whom other methods are more appropriate e.g. the programs mentioned previously that have been implemented for Indigenous communities.
Looking to the future, both urban and rural pet ownership will continue to flourish together with their adverse and beneficial effects on human health. The key to successful pet ownership lies in “balancing the interests” of all people involved through such programs as Municipal Pet Management and programs that consider the individual needs of each community.
Anderson WP, Reid CM, Jennings GL (1992). Pet Ownership and risk factors for cardiovascular disease. The Medical Journal of Australia. 157,298-301
Arden H (1995) Dreamkeepers. Harper Collins, Mossvale.
Australian Companion Animal Council (1995). The Power of Pets: a summary of the wide-ranging benefits of companion animal ownership. Artemon NSW: Australian Companion Animal Council.
Bell PA, Fisher JD, Loomis RJ (1978) Behavioural effects of noise, temperature, air pollution and wind. In: Environmental Psychology. London: Saunders: 93-127.
Friedmann E, Katcher AH, Lynch JJ, Thomas SA (1982). Animal Companions and one year survival of patients after discharge form a coronary care unit. California Veterinarian 8, 45-50.
Friedmann E, Katcher AH, Thomas SA et al. (1983) Social interaction and blood pressure influence of animal companions. Journal of Nervous Mental Disease 171, 461-465.
Headey BW (1995). Health benefits of Pets: Results from the Australian People and Pets Survey. Melbourne. Petcare Information and Advisory Service.
Hubert WT (1984) Caution: Pets may be hazardous to your health. Journal of the American Medical Association 251:934 – 935.
Murray RW, Penridge HE (1997) Dogs and Cats in the Urban Environment. Second Edition. Chiron Media, Mooloolah, Australia.
Murray RW (1991) An Analysis Of The Characteristics, Social Impact And Management Of The Townsville Dog population. MSc Thesis. Townsville. JCU.
[PIAS] Petcare Information and Advisory Service (1993) Pets in Urban Areas. A Guide to Integrating domestic pets into new Residential Development.. Harlock Jackson Pty Ltd. Victoria.
[PIAS] (1995) Public Open Space and Dogs. Harlock Jackson Pty Ltd. Victoria.
Ross H (1987) Halls Creek Aboriginal Culture. Just for Living, Aboriginal Perceptions of Housing in North West Australia, Aboriginal Studies Press, Canberra.
Shield J (1992) Some Problems of dog health and control in Aboriginal and Islander Communities in North Queensland. In: Urban Animal Management. Proceedings of the First National Conference on Urban Animal Management in Australia. Chiron Media, Mackay.
Stehr-Green JK, Schantz PM (1987) The Impact of Zoonotic Diseases Transmitted by Pets on Human Health and the Economy. In: The Veterinary Clinics of North America. Small Animal Practice. Vol. 17/ No. 1. January 1987.
Thompson P (1991) Dog Attacks. South Australian Health Commission Injury Surveillance Monthly Bulletin no 29:1-2.
Vine G (1993) Secret Power of Pets. New Scientist. October 1993.
Wilks K, Williamsen P (1998) The dog health program in Aboriginal Communities – a method for dog management in remote Aboriginal communities. In: Urban animal Management. Proceedings of the national Conference. Perth, 1998.