Part I: The Role of Animals in Public Health
By: Rosemary Stephen, Elements: Environmental Health Intelligence
Pets are very important in the lives of people around the world. Many of us feel we cannot live without our pets; I know I feel that way. I still remember the first cat we ever owned. We got him from a neighboring farmer who was giving away kittens. My sister and I chose a little male kitten, and we named him Blacky. We were so happy to have our own pet. Blacky had a funny personality. He did not like being left alone in a room so he would crouch down low in a corner or close to the furniture and either wait for us to come back, or take off like a bullet, bouncing off the walls, tying to find us. Unfortunately, we had to move so we had to find Blacky a new home. My sister and I did not have pets again for many years. Now, as adults, we have opened our homes (and hearts) again to pets. In my family, we have Sweety. She is a 10 year old female, tortoise shell cat who thinks of herself as our family nurse. She always stands guard over us when we are sick; she either sits on us or lies next to us when we are bedridden. When my son was young, she used join him in bed each night, sensing that he needed her presence, and the sound of her purr, to drift into a peaceful sleep.
We all have stories about our pets. This is why the Elements team decided that, since it is our first anniversary of publication, we should do something just a little bit different. We know that most of you are animal owners, so we decided to write a series of three blogs about animals in public health, environmental health and occupational health and safety. In this first blog, we will look at the positive impact animals have in public health.
Wars and Animal use in Public Health
I was surprised to discover that both domestic cats and dogs made a large contribution to public health in the two World Wars, playing an important role in the preservation of the health of soldiers.
World Wars and Cats
Cats were used extensively by the British Army during WWI. Somewhere in the range of half a million cats were ‘drafted’. They were donated by the British and US public to use in the trenches to keep rat and mice infestations down. Cats were also used by the British Army to detect poison gases on the battlefields. These gases included chlorine [1E, 2E], phosgene [2E, 3E] and mustard gas [4E] [1, 2, 3].
Photo credit: Roberts, P., At Sea… Ships’ Cats (2003) Cats in Wartime, Purr ‘n’ Fur Featuring Felines. (available: http://www.purr-n-fur.org.uk/featuring/war01.html)
The life of the military cat was a bit less dangerous in WWII when they were generally removed from the front lines and instead were used to guard food stores against rodents [4]. They did, however, go to sea with the navy. Cats were highly appreciated on naval vessels where they served three duties: as ship mascots, as crew companions providing a warm presence and as mousers to protect food stores from rodents. In 1975, however, the British Royal Navy banned cats aboard ships on the grounds of hygiene, sanitation and fear of rabies [5, 6].
World Wars and Dogs
During WWI and WW II dogs were trained as soldiers to add to the fighting forces, guards and patrol teams. Different breeds of dogs were used for different tasks. Some breeds were better at detecting explosives while others excelled at search and rescue and scouting. Dogs were responsible for the protection of convoys and were involved in carrying explosives. They also played a significant role on the battle fields in retrieving wounded soldiers [7].
Ambulance dogs
Lt.-Col. Edwin Hautenville Richardson, a noted dog fancier and founder of the first British War Dog School was the leading authority on dog training during the two world wars. He was inspired by reading ancient Greek and Roman warfare accounts to train dogs for different tasks on the battlefield. He selected dog breeds based on their endurance to great hardship; Collies, Retrievers, Bloodhounds, Airedale terriers, German shepherds and Doberman Pinschers were the preferred breeds [8, 9].
Before the start of WWI, Richardson visited a training school in Lechernich, Germany, where dogs were already being trained to find wounded soldiers on the battlefield. The dogs even wore their own uniform — a Red Cross jacket. Richardson was so impressed by these dogs that he bought one and returned with it to Britain. Once back at home, he started training other dogs based on what he had seen and on the skills of his new, German-trained dog. Richardson’s facilities trained both dogs and their handlers how to find, and then help, wounded soldiers. Richardson’s dogs did not wear a red cross uniform like the German dogs, instead they wore a saddlebag uniform that was equipped with compartments to store first-aid supplies and a “small flask of spirits…” which during training exercises “needed to be refilled quite often” [10].
Photo credit: A Pictorial Tour of the Dogs of War…On the Western Front (available: http://community-2.webtv.net/Hahn-50thAP-K9/K9History2/)
The French Army Red Cross also used especially trained dogs to help find wounded soldiers on the battlefield in WWI. Dogs would bring back a cap, a glove or a helmet to signal the attending ambulance-men that an injured solder needed help [11]. One of the most inspiring animal war stories involves Micheal, a French Army Red Cross ambulance dog. Micheal found Henri’s body lying lifeless and cold in a far corner of the battlefield. After a hasty examination, the attending field doctor declared Henri dead and left the body were it lay. Micheal, however, did not want to leave. After numerous attempts to persuade the ambulance-man to bring Henri’s body back, the dog returned to camp with the medical staff. Michael, however, soon disappeared again. Late that night, he returned, slowly dragging something heavy back to camp. Michael had returned to the battlefield and with dedication and devotion, had dragged Henri’s body back, inch by inch, from the battlefield. Surprised by this strange behavior – why would the dog drag back a dead body — the field doctor re-examined the lifeless soldier. He discovered that Henri was, in fact, breathing. After appropriate medical care, Henri recovered, owing his life to Michael [12].
Ambulance dogs are no longer used in today’s warfare. Field ambulances now have the duty to care for wounded soldiers.
Dogs as Rat catchers
Dogs have long been used to control pests. The British courts of Queen Elizabeth I and Queen Victoria entrusted Manchester Terriers with the royal duties of ridding their castles of rats [13]. Ratting duties continued in to WWI. One of Lt.-Col. Edwin Hautenville Richardson’s young pups, an Irish Terrier called Norah, was trained by Private Thomas Radford of the Canadian Veterinary Corps to become a ratter. She made headlines as “Champion rat dog of the western front” for having killed 628 rats in three years of service [14].
This type of pest control, however, does not appear to be popular today. I could only find one modern instance of dogs being trained specifically to track rats. In April 2008, a rat catching operation was launched on Motuihe Island (located in the Hauraki Gulf of New Zealand, close to Auckland) by the Department of Conservation (DOC) to rid the island of Norway rats. The island has a sensitive ecosystem that cannot afford the presence of this imported pest. Other islands in the Hauraki Gulf were also ’sniffed out’. According to the dogs, however, no traces of Norway rats were found on these islands [15].
Dogs and the Prevention of Coronary Heart Diseases
In Australia, about 50 % of homeowners have a pet; about 40% of these households own dogs. Since inactivity increases the rate of coronary heart disease, Australia Public Health decided to launch an investigation to identify if dog owners, who in theory walked their dogs daily, were more in shape than non-dog owners. The results of this investigation were surprising – they found that dog owners are not necessarily more in shape than non-dog owners. On the contrary, it seems that more than half of dog owners seldom walk their dogs ! The Australian Public Health dept noted that dog-owners are missing out on a great opportunity to get regular physical exercise that is good for them as well as their dogs [16].
So, what if dog owners were encouraged to walk their dogs, would it have any positive effect on health? Studies done in New South Wales, Australia indicated that if every single dog owner took the time to walk their dogs, health care costs would decrease by $175 million per year. This prompted the creation of national health and activity strategies slated to start in 2010 based on the DogEpi Concept. The DogEpi Concept is defined has the “epidemiological estimate of the proportion of disease which might be prevented if all dogs owners walked their dogs for at least 150 minutes per week”. If this estimate is correct, Australia’s Public Health will see a decrease in coronary heart disease and a 5% increase in the number of adults considered “sufficiently active”. Other benefits would be mental health improvement and stress reduction [17].
Zootherapy
Zootherapy encompasses three separate animal-based therapies: Animal Assisted Therapy (AAT), Animal Facilitated Therapy (AFT) and Hippotherapy. AAT allows adults and children to make physical contact with animals, usually dogs. The human body reacts positively to contact with animals; hugging and petting relieves stress, decreases blood pressure, decreases violent behavior and relieves depression in handicapped, isolated and incapacitated people. 
The program started in 1982 when Veterinary Assistant Nancy Stanley a noticed how well handicapped visitors reacted to animals housed at the Los Angeles Zoo. This inspired her to create Tender Loving Zoo (TLZ) a center for severely handicapped children and for elderly in convalescence to come into contact with zoo animals. Eventually, her program broadened to become Animal Assisted Therapy where animals were taken to care facilities to visit people. Initially only dogs were used in AAT, but now cats, elephants, birds, dolphins, rabbits and lizards are also used [18, 19].
Animal Facilitated Therapy (AFT) is the therapeutic use of animals to improve patients’ physical and emotional health. It helps patients re-learn skills lost following a medical condition. It is basically an alternative method for reaching people that are depressed and isolated. Randomized trials done on mild and moderate depression sufferers indicated net improvement in mental conditions after two weeks of interactions with dolphins [20].
Another interaction therapy that is gaining popularity is the ‘Psychiatric-service dog’. Eight week old puppies are initially trained for a period of 12 to 18 months in a prison setting by inmates called ‘puppy trainers’. There, dogs learn more than 80 voice commands before they are sent for further training. These dogs are usually destined to be guide dogs, but since 2006, many have been trained as aides for Iraq and Afghanistan war vets [21] ; between 10% and 30% of soldiers who have been on duty in war zones experience life-altering symptoms of post-traumatic stress disorder (PTSD) or mild traumatic brain injury (mTBI). Psychiatric service dogs generally work in veterans hospitals but 11 dogs have been placed permanently with war vets so far; the demand for such a service is growing [22]. These dogs are trained to recognize changes in their owner’s breathing, perspiration or scent, all possible signs of an eminent panic attack. They are also trained to bark and wake their owners when these are having nightmares [23]. Since Psychiatric dogs have entered service in care facilities, 82 % of veterans have experience a reduction in symptoms and another 40% reported a decrease in medication use [24].
Hippotherapy is a form of care which uses horses for therapeutic purposes as part of a rehabilitation strategy. A patient is evaluated prior to the start of treatment by physiotherapists, occupational therapists and speech / language specialists. Since horses have multidimensional movements that are variable, rhythmic and repetitive, they are used to stimulates the rider’s postural and muscular reactions. This movement pattern is similar to that of the pelvis when walking [25]. Hippotherapy results in improved balance and posture, increased mobility and function as well as improvement in psychological, cognitive, behavioral and communication functions of patients of all ages [26]. Two other benefits of hippotherapy for handicapped and mentally disabled people are an improvement both in self-esteem and in self-confidence. Since horses are non-judgmental, large and majestic in appearance, they help diminish a rider’s feeling of isolation and helplessness [27].
It’s all in the nose
Scientists have trained dogs to detect diseases and other health issues in people. Dogs are used to ’sniff out’ and warn of oncoming epileptic seizures, low blood sugar and heart attacks [28]. But what about cancer? Can dogs detect cancer by simply sniffing humans? More than 20 years ago, Gill Lacy noticed a persistent change in the behavior of her dog Trudi; she kept sniffing and licking a mole on Gill’s leg. After consulting with her family doctor, a biopsy was taken. The sample showed the presence of melanoma, a serious form of skin cancer. In 1989, The Lancet published dozens of similar accounts involving the detection by dogs of bowel, cervical and breast cancer [29]. Today, dogs are trained to detect cancer from samples (mostly breath and sometimes urine) for the presence or absence of cancer [30]. In 2006 the accuracy of dogs at identifying positive cancer samples was rated between 88% to 97% [31, 32]. More research in this field is being done and it looks promising. The early detection of cancer in the near future could only be one breath away.
How about rats as an inexpensive diagnostic tool
Gambian pouch rats (Cricetomys gambianus) are native to Senegal, Central Sudan and South Africa. They are a large muriod rodent [6E, 33] which have hamster-like pouches in their cheeks. This rat is omnivorous so it eats a variety of foods including vegetable, insects, crabs and snails, but they prefer palm fruits and palm kernels. These rats are nocturnal animals, so they rely on their highly developed sense of smell to forage for food. A Belgium company is, at the moment, taking advantage of this trait by training pouch rats to detect land mines. Trained at an early age, these rats are thought to associate the smell of explosives with food [34]. The overall adaptability of Gambian rats makes them easy to train [35], taking only four to six months. Their longevity in captivity – between 8 to 10 years – makes them a long lasting, useful, accurate and inexpensive diagnostic tool.
Gambian pouch rats have been used since 2003 in developing countries in a Public Health role. They have been trained to diagnose TB from human saliva [36]. It takes a pouch rat approximately 30 minutes to sniff 120-150 human saliva samples in a lab. If the saliva is negative for TB, the rat will go to the next successive sample. When a rat finds a sample that is positive for TB, it will stop in front of that sample and wait to be rewarded with a food treat [37, 38]. This testing method has proven to be the most economical method for the early identification of TB in humans in developing countries. It may soon find its place in developed countries too.
Conclusion:
These examples are just a sample of what animals have done and still do for Public Health. Cats and dogs were used extensively during both World Wars. Cats played a role in the protection of troops against mice and rat infestations in trenches. They also protected stored food and warned soldiers of the presence of gases in trenches. Aboard ships, they provided companionship and prevented rodent infestations.
Dogs were trained as ambulance dogs during WWI and WWII. Thanks to their training, wounded soldiers on the battle field, were brought back to camp where they could receive appropriate medical care. Dogs also served during WWI as ratters, ridding trenches from dangerous rats and hence protecting soldiers from vector diseases. More recently, a dog has been used to locate rats on islands in the Pacific to protect the existing biodiversity.
Zootherapy encompasses three valuable types of therapy. Animal Facilitated Therapy (AFT) and Animal Facilitated Therapy (AFT) are now providing service to people in need while a new therapy – Psychiatric service dogs – is helping veterans cope with life-altering symptoms of post-traumatic stress disorder (PTSD) or mild traumatic brain injury (mTBI). Hippotherapy done with horses, allows physiotherapists, occupational therapists and speech language specialists to create training programs that meet the needs of disable patients to learn or re-learn body movements.
The application of using animals in the early detection of cancer and TB looks very promising. Dogs are being trained to sniff out cancers from a breath sample with a high rate of accuracy. The introduction of animals such has the Gambian pouch rat in the detection of TB in saliva is a welcome intervention for developing countries which cannot afford sophisticated detection tools.
The second blog of the series will look at animal contribution in the Environmental Health sector.
Rosemary Stephen (2009). At Your Service… Elements: Environmental Health Intelligence
Endnotes:
Chlorine is a greenish yellow gas that is two and a half times heavier than air. Since it is corrosive in moist conditions, it irritates the eyes and respiratory system. It was used during WWI in trench warfare. (1E, 2E).
Phosgene gas is twice as toxic as chlorine. Soldiers were exposed to this gas during WWI trench warfare. It has a delayed effect on the body and once inhaled is fatal within 48 hrs (3E). Phosgene has a unpleasant, irritating smell with a hint of mown hay (4E).
Mustard gas actually starts as a liquid and changes into a gas when released. As a liquid, it is colorless and odorless, but when mixed with other chemicals, it looks brown and has a garlic-like smell. It is an irritant and was used during WWI in trench warfare to cause chemical burns (5E).
Muroidea is a large superfamily of rodents. It includes hamsters, gerbils, true mice and rats, and many other relatives (6E)
Endnotes References:
[1E] Chlorine gas (2009) Spartacus Educational. (On-line) Available: http://www.spartacus.schoolnet.co.uk/FWWchlorine.htm. Cited 2009 30.
[2E] Chlorine (2009) Search. (On-line) Available: http://www.c-f-c.com/specgas_products/chlorine.htm. Cited 2009 Oct 30.
[3E] What are some poison gases used in World War 1? (2009) Answer.com (On-line) Available: http://wiki.answers.com/Q/What_are_some_poison_gases_used_in_World_War_1. Cited 2009 Oct 30.
[4E] Engber, D., Does Poison Gas Smell Good? (2009) Slate. (On-line) Available: http://www.slate.com/id/2148198/. Cited 2009 Oct 30.
[5E] Gas (2009) Digger History. (On-line) Available: http://www.diggerhistory.info/pages-weapons/gas.htm. Cited 2009 Oct 30.
[6E] Muroidea (2009) Wikipedia, the free encyclopedia. (On-line) Available: http://en.wikipedia.org/wiki/Muroid_rodents. Cited 2009 Oct 28.
Article References:
[1] Poison Gas and World War One (2009) Ask.com (On-line) Available: http://www.historylearningsite.co.uk/poison_gas_and_world_war_one.htm. Cited 2099 Oct 26.
[2] Saigeon, J. R. New Weapons used for the first time in World War I (1998) Trench Warfare (On-line) Available: http://www.harris-academy.com/departments/history/Trenches/Joanna/joanna2.htm. Cited 2009 Oct 28.
[3] Roberts, P. On Land and in the Air (2003) Cats in Wartime, Purr ‘n’ Fur Featuring Felines. (On-line) Available: http://www.purr-n-fur.org.uk/featuring/war01.html. Cited 2009 Sept 22.
[4] Ibid. Cited 2009 Sept 22.
[5] Ibid. Cited 2009 Sept 22.
[6] Arms and the Cat. (2007) UK National Inventory of War Memorials (UKNIWM). (On-line) Available: http://ukniwm.wordpress.com/2007/08/17/arms-and-the-cat/. Cited 2009 Sept 22.
[7] Ambulance Dogs (2009) Free Books / Animals / Dogs Of All Nations /, Chest of Books.com. (On-line) Available: http://chestofbooks.com/animals/dogs/Dogs-All-Nations/Ambulance-Dogs.html. Cited 2009 Sept 14.
[8] Bovsun, M., In recognition of Armistice Day, we salute the dogs who served in World War I. All K-9s on the Western Front (2009) Hartsdale Pet Cemetery and Crematory. (On-line) Available: http://www.petcem.com/news.html. Cited 2009 Sept 14.
[9] A biography of E.H. Richardson.(2009) A Special Presentation From Hahn’s 50th AP K-9, West Germany. (On-line) Available: http://community-2.webtv.net/Hahn-50thAP-9/K9History13/index.html. Cited 2009 Sept 15.
[10]Ibid. Cited 2009 Sept 15.
[11] Man Best Friend Goes to War (2009) The Dogs of War on the Battlegrounds. (On-line) Available: http://www.greatwardifferent.com/Great_War/Animals_at_War/Dogs_Text_01.htm. Cited 2009 Sept 22.
[12] Bovsun, M., In recognition of Armistice Day, we salute the dogs who served in World War I. All K-9s on the Western Front (2009) Hartsdale Pet Cemetery and Crematory. (On-line) Available: http://www.petcem.com/news.html. Cited 2009 Sept 14.
[13] Part One: History of the Manchester Terrier. (2009) The British Manchester Terrier Club. (On-line) Avialable: http://www.british-manchester-terrier-club.co.uk/develop.htm. Cited 2009 Sept 22.
[14] Bovsun, M., In recognition of Armistice Day, we salute the dogs who served in World War I. All K-9s on the Western Front (2009) Hartsdale Pet Cemetery and Crematory. (On-line) Available: http://www.petcem.com/news.html. Cited 2009 Sept 14.
[15] Specially trained dog tracks rat on rodent free island (2008) WildlifeExtra.com. (On-line) Available: http://www.wildlifeextra.com/go/news/motuihe-rat345.html#cr. Cited 2009 Oct 28.
[16] Bauman, A. E. and al. The epidemiology of dog walking: an unmet need for human and canine health. (2001) The Medical Journal of Australia. (On-line) Available: http://www.mja.com.au/public/issues/175_12_171201/bauman/bauman.html. Cited 2009 Sept 14.
[17] Ibid. Cited 2009 Sept 14.
[18] Illminatus, Pet Therapy Training and Pet Assisted Therapy, How they work.(2009) HubPages. (On-line) Available: http://hubpages.com/hub/Pet-Therapy-Training-and-Pet-Assisted-Therapy–How-they-work. Cited 2009 Sept 17.
[19] Therapy dog (2009) Wikipedia, the free encyclopedia (On-line) Available: http://en.wikipedia.org/wiki/Therapy_dog. Cited 2009 Oct 23.
[20] Antonioli, C. and Reveley, M. Randomised controlled trial of animal facilitated therapy with dolphins in the treatment of depression (2005) BMJ. (On-line) Available: http://www.bmj.com/cgi/content/full/331/7527/1231?ehom. Cited 2009 Oct 23.
[21] A New Leash on Life, History (2009) Puppies Behind Bars. (On-line) Available: http://www.puppiesbehindbars.com/about.asp. Cited 2009 Nov 06.
[22] Dreazen, Y.J. ‘Sit! Stay! Snuggle!’: An Iraq Vet Finds His Dog Tuesday (2009) The Wall Street Journal. (On-line) Available: http://online.wsj.com/article/SB124727385749826169.html. Cited 2009 Nov 05.
[23] Ibid. Cited 2009 Nov 05.
[24] Love, C. Ph.D.and Esnayra, J. The Use of Psychiatric Service Dogs with Soldiers Who Have PTSD (2008) Psychiatric Service Dog Society (PSDS). (On-line) Available: http://www.psychdog.org/news_innovative_therapies.html. Cited 2009 Nov 06.
[25] Canadian Therapeutic Riding Association (2006) CanTra and Hippotherapy. (On-line) Available: http://www.cantra.ca/hippotherapy.shtml. Cited 2009 Oct 26.
[26] Therapeutic Riding Program (2009) American Hippotherapy Association. (On-line) Available: http://www.americanequestrian.com/hippotherapy.htm. Cited 2009 Oct 28.
[27] Memory and Self-esteem in Down’s Syndrome: Does Therapeutic Riding Have Any Significant Effect? (2006) Contact Between friends , XII International Congress of Therapeutic Riding (On-line) Available: http://www.ncpg-kenniscentrum.nl/documenten/twaalfdeintcongresfrdi.pdf. Cited 2009 Nov 06.
[28] Masland, M. Is there a doctor — or dog — in the house? Canine sense of smell could help diagnose disease (2004) MSNBC. (On-line) Available: http://www.msnbc.msn.com/id/5183290/. Cited 2009 Oct 27.
[29] Dogs Sniffing Cancer: Dogs hound out serious disease (2009) DogsLife. (On-line) Available: http://www.dogslife.com.au/dogs_life_articles?cid=9454&pid=6322651. Cited 2009 Oct 27.
[30] Tobiassen Crosby, J. Dogs Sniffing Out Disease. (2009) About.com: Veterinary Medicine. (On-line) Available: http://vetmedicine.about.com/b/2009/07/24/disease-sniffing-dogs.htm. Cited 2009 Oct 27.
[31] Can Dogs Smell Cancer? (2006) Science Daily. (On-line) Available: http://www.sciencedaily.com/releases/2006/01/060106002944.htm. Cited 2009 Oct 29.
[32] Can Dogs Detect Cancer? (2009) Pine Street Foundation (On-line) Available: http://pinestreetfoundation.org/2009/05/14/can-dogs-detect-cancer/.Cited 2009 Oct 27.
[33] Gambian Pouch Rat (Cricetomys gambianus) (1995) Animal Photo Album. (On-line) Available: http://www.animalpicturesarchive.com/view.php?tid=3&did=28664. Cited 2009 Oct 28.
[34] Chris. Unusual Military Animals (2007) Cynical-C Blog. (On-line) Available: http://www.cynical-c.com/?p=7820. Cited 2009 Sept 22.
[35] The Giant Rats are in the News again.(2008) Keys Treasures Pouch Rat Page, Keys Treasures. (On-line) Available: http://floridakeystreasures.com/creatures/pouchrat/. Cited 2009 Sept 22.
[36] Training African Rats as a Cheap Diagnostic Tool. (2009) The World Bank. (On-line) Available: http://web.worldbank.org/WBSITE/EXTERNAL/OPPORTUNITIES/GRANTS/DEVMARKETPLACE/0,,contentMDK:21431202~pagePK:180691~piPK:246778~theSitePK:205098,00.html. Cited 2009Sept 22.
[37] Balile, D. Tanzania trains rats to detect tuberculosis.(2003) SciDev Net (Science and Development Network). (On-line) Available: http://www.scidev.net/en/news/tanzania-trains-rats-to-detect-tuberculosis.html. Cited 2009 Sept 22.
[38] The Giant Rats are in the News again.(2008) Keys Treasures Pouch Rat Page, Keys Treasures. (On-line) Available: http://floridakeystreasures.com/creatures/pouchrat/. Cited 2009 Sept 22.
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