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Pet, Furbearer and Laboratory Animal Protection

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Institutional animal programmes involve four major processes:

  1. receipt, quarantine and separation of animals
  2. separation of species or animals for individual projects when necessary
  3. housing, care and sanitation
  4. storage.


Husbandry tasks include feeding, watering, providing bedding, maintaining sanitation, disposing of waste including carcasses, controlling pests and veterinarian care. Materials handling is significant in most of these tasks, which include moving cages, feed, pharmaceuticals, biologics and other supplies. Handling and manipulating animals is also fundamental to this work. Sanitation involves changing bedding, cleaning and disinfecting, and cage washing is a significant sanitation task.

Institutional animal facilities include cages, hutches, pens or stalls within a room, barn or outdoor habitat. Adequate space, temperature, humidity, food and water, illumination, noise control and ventilation are provided in a modern facility. The facility is designed for the type of animal that is confined. Animals that are typically confined in institutional settings include group-housed rodents (mice, rats, hamsters and guinea pigs), rabbits, cats, dogs, mink, non-human primates (monkeys, baboons and apes), birds (pigeons, quail and chickens) and farm animals (sheep and goats, swine, cattle, horses and ponies).

Hazards and Precautions

Persons involved with the production, care and handling of pet, furbearer and laboratory animals are potentially exposed to a variety of biological, physical and chemical hazards that can be controlled effectively through available risk reduction practices. The biological hazards intrinsic to the various animal species of concern to personnel include: bites and scratches; highly sensitizing allergens in dander, serum, tissues, urine or salivary secretions; and a wide variety of zoonotic agents. Although the biological hazards are more diverse and potentially more devastating in the work environments supporting these types of animals, the physical and chemical hazards generally are more pervasive, as reflected by their contribution to illness and injury in the workplace.

Personnel involved in the care and production of pet, furbearer or laboratory animals should receive appropriate training in handling techniques and behaviour of the animal species in question, because incorrect handling of an intractable animal frequently is a precipitating cause of a bite or scratch. Such injuries can become contaminated with micro-organisms from the animal’s rich oral and skin microflora or the environment, necessitating immediate wound disinfection and prompt and aggressive antimicrobial therapy and tetanus prophylaxis to avert the serious complications of wound infection and disfigurement. Personnel should appreciate that some zoonotic bite infections can produce generalized disease and even death; examples of the former include cat scratch fever, rat bite fever and human orf infection; examples of the latter include rabies, B virus and hantavirus infection.

Due to these extraordinary risks, wire-mesh, bite-proof gloves can be beneficial in some circumstances, and the chemical restraint of animals to facilitate safe handling is sometimes warranted. Personnel also can contract zoonoses through the inhalation of infectious aerosols, contact of the organisms with the skin or mucous membranes, ingestion of infectious materials or transmission by specific fleas, ticks or mites associated with the animals.

All types of zoonotic agents occur within pet, furbearer and laboratory animals, including viruses, bacteria, fungi and internal and external parasites. Some examples of zoonoses include: giardiasis and campylobacterosis from pets; anthrax, tularaemia and ringworm from furbearers; and lymphocytic choriomeningitis, hantavirus and dwarf tapeworm infestation from the laboratory rodent. The distribution of zoonotic agents varies widely according to host animal species, location and isolation from other disease reservoirs, housing and husbandry methods, and history and intensity of veterinary care. For example, some of the commercially produced laboratory animal populations have undergone extensive disease eradication programmes and been maintained subsequently under strict quality control conditions precluding the reintroduction of diseases. However, comparable measures have not been applicable universally in the various settings for pet, furbearer and laboratory animal maintenance and production, enabling the persistence of zoonoses in some circumstances.

Allergic reactions, ranging from ocular and nasal irritation and drainage to asthma or manifesting on the skin as contact urticaria (“hives”), are common in individuals who work with laboratory rodents, rabbits, cats and other animal species. An estimated 10 to 30% of individuals working with these animal species eventually develop allergic reactions, and persons with pre-existing allergic disease from other agents are at higher risk and have an increased incidence of asthma. In rare circumstances, such as a massive exposure to the inciting allergen through an animal bite, susceptible persons can develop anaphylaxis, a potentially life-threatening generalized allergic reaction.

Good personal hygiene practices should be observed by personnel to reduce their likelihood of exposure to zoonoses and allergens during work with animals or animal by-products. These include the use of dedicated work clothing, the availability and use of hand washing and shower facilities and separation of personnel areas from animal housing areas. Work clothing or protective outer garments covering the skin should be worn to prevent exposure to bites, scratches and hazardous microbes and allergens. Personal protective equipment, such as impervious gloves, safety glasses, goggles or other eye protection, and respiratory protection devices (e.g., particle masks, respirators or positive air pressure respirators) appropriate to the potential hazards and the individual’s vulnerability, should be provided and worn to promote safe work conditions. Engineering controls and equipment design also can effectively reduce the exposure of personnel to hazardous allergens and zoonoses through directional air flow and the use of isolation caging systems that partition the workers’ and animals’ environments.

Personnel also encounter significant physical and chemical hazards during animal care. Routine husbandry tasks involve moving or lifting heavy equipment and supplies, and performing repetitive tasks, affording personnel the ubiquitous opportunity to develop cuts and crush injuries, muscular strains and repetitive motion injuries. Work practice redesign, specialized equipment and personnel training in safe work practices can be used to curb these untoward outcomes. Equipment and facility sanitation frequently relies on machinery operating on live steam or extremely hot water, placing personnel at risk of severe thermal injury. The correct design, maintenance and utilization of these devices should be assured to prevent personnel injury and facilitate heat dissipation to provide a comfortable work environment. Personnel who work around large equipment, as well as around rambunctious dog or non-human primate populations, may be exposed to extremely high noise levels, necessitating the use of hearing protection. The various chemicals used for cage and facility sanitation, pest control within the animal facility and external parasite control on animals should be reviewed carefully with personnel to ensure their strict adherence to practices instituted to minimize exposure to these potentially irritating, corrosive or toxic substances.



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Part I. The Body
Part II. Health Care
Part III. Management & Policy
Part IV. Tools and Approaches
Part V. Psychosocial and Organizational Factors
Part VI. General Hazards
Part VII. The Environment
Part VIII. Accidents and Safety Management
Part IX. Chemicals
Part X. Industries Based on Biological Resources
Agriculture and Natural Resources Based Industries
Beverage Industry
Food Industry
Livestock Rearing
Paper and Pulp Industry
Part XI. Industries Based on Natural Resources
Part XII. Chemical Industries
Part XIII. Manufacturing Industries
Part XIV. Textile and Apparel Industries
Part XV. Transport Industries
Part XVI. Construction
Part XVII. Services and Trade
Part XVIII. Guides

Livestock Rearing References

Aldhous, P. 1996. Scrapie theory fed BSE complacency, now fears grow for unborn babies. New Scientist 150:4-5.

Ahlgren, GH. 1956. Forage Crops. New York: McGraw-Hill Book Co.

American Conference of Governmental Industrial Hygienists (ACGIH). 1994. Threshold Limit Values for Chemical Substances and Physical Agents and Biological Exposure Indices. Cincinnati, OH: ACGIH.

Auty, JH. 1983. Draught animal power in Australia. Asian Livestock VIII:83-84.

Banwart, WC and JM Brenner. 1975. Identification of sulfur gases evolved from animal manures. J Environ Qual 4:363-366.

Baxter, PJ. 1991. Toxic marine and freshwater algae: An occupational hazard? Br J Ind Med 48(8):505-506.

Bell, RG, DB Wilson, and EJ Dew. 1976. Feedlot manure top dressing for irrigated pasture: Good agricultural practice or a health hazard? B Environ Contam Tox 16:536-540.

Benenson, AS. 1990. Control of Communicable Diseases in Man. Washington, DC: American Public Health Association.

—. 1995. Control of Communicable Diseases Manual. Washington, DC: American Public Health Association.

Brown, LR. 1995. Meat production takes a leap. In Vital Signs 1995: The Trends that are Shaping our Future, edited by LR Brown, N Lenssen, and H Kane. New York: WW Norton & Company.

Bursey, RG. 1992. New uses of dairy products. In New Crops, New Uses, New Markets: Industrial and Commercial Products from U.S. Agriculture: 1992 Yearbook of Agriculture. Washington, DC: USDA.

Calandruccio, RA and JH Powers. 1949. Farm accidents: A clinical and statistical study covering twenty years. Am Surg (November):652-660.

Cameron, D and C Bishop. 1992. Farm accidents in adults. Br Med J 305:25-26.

Caras, RA. 1996. A Perfect Harmony: The Intertwining Lives of Animals and Humans throughout History. New York: Simon & Schuster.

Carstensen, O, J Lauritsen, and K Rasmussen. 1995. The West-Justland study on prevention of farm accidens, Phase 1: A study of work specific factors in 257 hospital-treated agricultural injuries. Journal of Agricultural Safety and Health 1:231-239.

Chatterjee, A, D Chattopadhyay, D Bhattacharya, Ak Dutta, and DN Sen Gupta. 1980. Some epidemiologic aspects of zoophilic dermatophytosis. International Journal of Zoonoses 7(1):19-33.

Cherry, JP, SH Fearirheller, TA Foglis, GJ Piazza, G Maerker, JH Woychik, and M Komanowski. 1992. Innovative uses of animal byproducts. In New Crops, New Uses, New Markets: Industrial and Commercial Products from U.S. Agriculture: 1992 Yearbook of Agriculture. Washington, DC: USDA.

Crowley, M. 1995. Aquaculture trends and technology. National Fisherman 76:18-19.

Deere & Co. 1994. Farm and Ranch Safety Management. Moline, IL: Deere & Co.

DeFoliart, GR. 1992. Insects as human foods. Crop Protection 11:395-399.

Donham, KJ. 1985. Zoonotic diseases of occupational significance in agriculture: A review. International Journal of Zoonoses 12:163-191.

—. 1986. Hazardous agents in agricultural dusts and methods of evaluation. Am J Ind Med 10:205-220.

Donham, KJ and LW Knapp. 1982. Acute toxic exposure to gases from liquid manure. J Occup Med 24:142-145

Donham, KJ and SJ Reynolds. 1995. Respiratory dysfunction in swine production workers: Dose-response relationship of environmental exposures and pulmonary function. Am J Ind Med 27:405-418.

Donham, KJ and L Scallon. 1985. Characterization of dusts collected from swine confinement buildings. Am Ind Hyg Assoc J 46:658-661.

Donham, KJ and KM Thu. 1995. Agriculture medicine and enivronmental health: The missing component of the sustainable agricultural movement. In Agricultural health and safety: Workplace, Environment, Sustainability, edited by HH McDuffie, JA Dosman, KM Semchuk, SA Olenchock, and A Senthilselvan. Boca Raton, FL: CRC Press.

Donham, KJ, MJ Rubino, TD Thedell and J Kammenmeyer. 1977. Potential health hazards of workers in swine confinement buildings. J Occup Med 19:383-387.

Donham, KJ, J Yeggy, and RR Dauge. 1985. Chemical and physical parameters of liquid manure from swine confinement facilities: Health implications for workers, swine and the environment. Agricultural Wastes 14:97-113.

—. 1988. Production rates of toxic gases from liquid manure: Health implications for workers and animals in swine buildings. Bio Wastes 24:161-173.

Donham, KJ, DC Zavala, and JA Merchant. 1984. Acute effects of work environment on pulmonary functions of swine confinement workers. Am J Ind Med 5:367-375.

Dosman, JA, BL Graham, D Hall, P Pahwa, H McDuffie, M Lucewicz, and T To. 1988. Respiratory symptoms and alterations in pulmonary function tests in swine producers in Saskatchewan: Results of a survey of farmers. J Occ Med 30:715-720.

Douglas, JDM. 1995. Salmon farming: Occupational health in a new rural industry. Occup Med 45:89-92.

Douglas, JDM and AH Milne. 1991. Decompression sickness in fish farm workers: A new occupational hazard. Br Med J 302:1244-1245.

Durning, AT and HB Brough. 1992. Reforming the livestock economy. In State of the World, edited by LR Brown. London: WW Norton & Company.

Erlich, SM, TR Driscoll, JE Harrison, MS Frommer, and J Leight. 1993. Work-related agricultural fatalities in Australia, 1982-1984. Scand J Work Environ Health 19:162-167.

Feddes, JJR and EM Barber. 1994. Agricultural engineering solutions to problems of air contaminants in farm silos and animal buildings. In Agricultural Health and Safety: Workplace, Environment, Sustainability, edited by HH McDuffie, JA Dosman, KM Semchuk, SA Olenchock and A Senthilselvan. Boca Raton, FL: CRC Press.

Ferguson, IR and LRC Path. 1993. Rats, fish and Weil’s disease. Safety and Health Practitioner :12-16.

Food and Agriculture Organization (FAO) of the United Nations. 1965. Farm Implements for Arid and Tropical Regions. Rome: FAO.

—. 1995. The State of the World Fisheries and Aquaculture. Rome: FAO.

Fretz, P. 1989. Injuries from farm animals. In Principles of Health and Safety in Agriculture, edited by JA Dosman and DW Crockcroft. Boca Raton, FL: CRC Press.

Froehlich, PA. 1995. Engineering Control Observations and Recommendations for Insect Rearing Facilities. Cincinnati, OH: NIOSH.

Gillespie, JR. 1997. Modern Livestock and Poultry Production. New York: Delmar Publishers.

Gorhe, DS. 1983. Draught animal power vs mechanization. Asian Livestock VIII:90-91.

Haglind, M and R Rylander. 1987. Occupational exposure and lung function measurements among workers in swine confinement buildings. J Occup Med 29:904-907.

Harries, MG and O Cromwell. 1982.Occupational allergy caused by allergy to pig’s urine. Br Med J 284:867.

Heederick, D, R Brouwer, K Biersteker, and J. Boleij. Relationship of airborne endotoxin and bacteria levels in pig farms with lung function and respiratory symptoms of farmers. Intl Arch Occup Health 62:595-601.

Hogan, DJ and P Lane. 1986. Dermatologic disorders in agriculture. Occup Med: State Art Rev 1:285-300.

Holness, DL, EL O’Glenis, A Sass-Kortsak, C Pilger, and J Nethercott. 1987. Respiratory effects and dust exposures in hog confinement farming. Am J Ind Med 11:571-580.

Holness, DL and JR Nethercott. 1994. Acute and chronic trauma in hog farmers. In Agricultural Health and Safety: Workplace, Environment, Sustainability, edited by HH McDuffie, JA Dosman, KM Semchuk, SA Olenchock, and A Senthilselvan. Boca Raton, FL: CRC Press.

Iowa Department of Public Health. 1995. Sentinel Project Research Agricultural Injury Notification System. Des Moines, IA: Iowa Department of Public Health.

Iverson, M, R Dahl, J. Korsgaard, T Hallas, and EJ Jensen. 1988. Respiratory symptoms in Danish farmers: An epidemiological study of risk factors. Thorax 48:872-877.

Johnson, SA. 1982. Silkworms. Minneapolis, MN: Lerner Publications.

Jones, W, K Morring, SA Olenchock, T Williams, and J. Hickey. 1984. Environmental study of poultry confinement buildings. Am Ind Hyg Assoc J 45:760-766.

Joshi, DD. 1983. Draught animal power for food production in Nepal. Asian Livestock VIII:86-87.

Ker, A. 1995. Farming Systems in the African Savanna. Ottawa,Canada: IDRC Books.

Khan, MH. 1983. Animal as power source in Asian agriculture. Asian Livestock VIII:78-79.

Kiefer, M. 1996. Florida Department of Agriculture and Consumer Services Division of Plant Industry, Gainesville, Florida. Cincinnati, OH: NIOSH.

Knoblauch, A, B Steiner, S Bachmann, G Trachsler, R Burgheer, and J Osterwalder. 1996. Accidents related to manure in eastern Switzerland: An epidemiological study. Occup Environ Med 53:577-582.

Kok, R, K Lomaliza, and US Shivhare. 1988. The design and performance of an insect farm/chemical reactor for human food production. Canadian Agricultural Engineering 30:307-317.

Kuo, C and MCM Beveridge. 1990. Mariculture: Biological and management problems, and possible engineering solutions. In Engineering for Offshore Fish Farming. London: Thomas Telford.

Layde, PM, DL Nordstrom, D Stueland, LB Wittman, MA Follen, and KA Olsen. 1996. Animal-related occupational injuries in farm residents. Journal of Agricultural Safety and Health 2:27-37.

Leistikow, B Donham, JA Merchant, and S Leonard. 1989. Assessment of U.S. poultry worker respiratory risk. Am J Ind Med 17:73-74.

Lenhart, SW. 1984. Sources of respiratory insult in the poultry processing industry. Am J Ind Med 6:89-96.

Lincoln, JM and ML Klatt. 1994. Preventing Drownings of Commercial Fishermen. Anchorage, AK: NIOSH.

MacDiarmid, SC. 1993. Risk analysis and the importation of animals and animal products. Rev Sci Tech 12:1093-1107.

Marx, J, J Twiggs, B Ault, J Merchant, and E Fernandez-Caldas. 1993. Inhaled aeroallergen and storage mite reactivity in a Wisconsin farmer nested case-control study. Am Rev Respir Dis 147:354-358.

Mathias, CGT. 1989. Epidemiology of occupational skin disease in agriculture. In Principles of Health and Safety in Aagriculture, edited by JA Dosman and DW Cockroft. Boca Raton, FL: CRC Press.

Meadows, R. 1995. Livestock legacy. Environ Health Persp 103:1096-1100.

Meyers, JR. 1997. Injuries among Farm Workers in the United States, 1993. DHHS (NIOSH) Publication No. 97-115. Cincinnati, OH: NIOSH.

Mullan, RJ and LI Murthy. 1991. Occupational sentinel health events: An up-dated list for physician recognition and public health surveillance. Am J Ind Med 19:775-799.

National Institute for Occupational Safety and Health (NIOSH). 1993. Injuries among Farm Workers in the United states. Cincinnati, OH: NIOSH.

—. 1994. Request for Assistance in Preventing Organic Dust Toxic Syndrome. Washington, DC: GPO.

National Institutes of Health (NIH). 1988. Institutional Administrator’s Manual for Laboratory Animal Care and Use. Washington, DC: GPO.

National Research Council (NRC). 1989. Alternative Agriculture: Committee on the Role of Alternative Farming Methods in Modern Production Agriculture. Washington, DC: National Academy Press.

National Safety Council. 1982. Accident Facts. Chicago, IL: National Safety Council.

—. 1985. Electrofishing. NSC data sheet I-696-85. Chicago, IL: National Safety Council.

Nesheim, MC, RE Austic, and LE Card. 1979. Poultry Production. Philadelphia, PA: Lea and Febiger.

Olenchock, S, J May, D Pratt, L Piacitelli, and J Parker. 1990. Presence of endotoxins in different agricultural environments. Am J Ind Med 18:279-284.

O’Toole, C. 1995. Alien Empire. New York: Harper Collins Publishers.

Orlic, M and RA Leng. 1992. Prelimenary Proposal to Assist Bangladesh to Improve Ruminant Livestock Productivity and Reduce Methane Emissions. Washington, DC: US Environmental Protection Agency, Global Change Division.

Panti, NK and SP Clark. 1991. Transient hazardous conditions in animal building due to manure gas release during slurry mixing. Applied Engineering in Agriculture 7:478-484.

Platt, AE. 1995. Aquaculture boosts fish catch. In Vital Signs 1995: The Trends that Are Shaping our Future, edited by LR Brown, N Lenssen, and H Kane. New York: WW Norton & Company.

Pursel, VG, CE Rexroad, and RJ Wall. 1992. Barnyard biotchnology may soon produce new medical therapeutics. In New Crops, New Uses, New Markets: Industrial and Commercial Products from U.S. Agriculture: 1992 Yearbook of Agriculture Washington, DC: USDA.

Ramaswami, NS and GL Narasimhan. 1982. A case for building up draught animal power. Kurushetra (India’s Journal for Rural Development) 30:4.

Reynolds, SJ, KJ Donham, P Whitten, JA Merchant, LF Burmeister, and WJ Popendorf. 1996. A longitudinal evaluation of dose-response relationships for environmental exposures and pulmonary function in swine production workers. Am J Ind Med 29:33-40.

Robertson, MH, IR Clarke, JD Coghlan, and ON Gill. 1981. Leptospirosis in trout farmers. Lancet: 2(8247)626-627.

Robertson, TD, SA Ribeiro, S Zodrow, and JV Breman. 1994. Assessment of Strategic Livestock Feed Supplementation as an Opportunity for Generating Income for Small Scale Dairy Producers and Reducing Methane Emissions in Bangladesh. Washington, DC: US Environmental Protection Agency.

Rylander, R. 1994. Symptoms and mechanisms: Inflammation of the lung. Am J Ind Med 25:19-24.

Rylander, R, KJ Donham, C Hjort, R Brouwer, and D Heederik. 1989. Effects of exposure to dust in swine confinement buildings: A working group report. Scand J Work Environ Health 15:309-312.

Rylander, R and N Essle. 1990. Bronchial hyperactivity among pig and dairy farmers. Am J Ind Med 17:66-69.

Rylander, R, Y Peterson, and KJ Donman. 1990. Questionnaire evaluating organic dust exposure. Am J Ind Med 17:121-128.

Rylander, R and R Jacobs. 1994. Organic Dusts: Exposure, Effects and Prevention. Chicago, IL: Lewis Publishing.
Safina, C. 1995. The world’s imperiled fish. Sci Am 272:46-53.

Scherf, BD. 1995. World Watch List for Domestic Animal Diversity. Rome: FAO.

Schmidt, MJ. 1997. Working elephants. Sci Am 279:82-87.

Schmidt, JO. 1992. Allergy to venomous insects. In The Hive and the Honey Bee, edited by JM Graham. Hamilton: DaDant & Sons.

Shumacher, MJ and NB Egen. 1995. Significance of Africanized bees on public health. Arch Int Med 155:2038-2043.

Sherson, D, I Hansen, and T Sigsgaard. 1989. Occupationally related respiratory symptoms in trout-processing workers. Allergy 44:336-341.

Stem, C, DD Joshi, and M Orlic. 1995. Reducing Methane Emissions from Ruminant Livestock: Nepal prefeasibility Study. Washington, DC: US Environmental Protection Agency, Global Change Division.

Sweeten, JM. 1995. Odor measurement technology and applications: A state-of-the-art review. In Seventh International Symposium on Agricultural and Food Processing Wastes: Proceedings of the 7th International Symposium, edited by CC Ross. American Society of Agricultural Engineering.

Tannahill, R. 1973. Food in History. New York: Stein and Day.

Thorne, PS, KJ Donham, J Dosman, P Jagielo, JA Merchant, and S Von Essen. 1996. Occupational health. In Understanding the Impacts of Large-scale Swine Production, edited by KM Thu, D Mcmillan, and J Venzke. Iowa City, IA: University of Iowa.

Turner, F and PJ Nichols. 1995. Role of the epithelium in the response of the airways. Abstract for the 19th Cotton and Other Organic Dust Research Conference, 6-7 January, San antonio, TX.

United Nations Development Programme (UNDP). 1996. Urban Agriculture: Food, Jobs, and Sustainable Cities. New York: UNDP.

US Department of Agriculture (USDA). 1992. Agricultural Waste Management Field Handbook. Washington, DC: USDA Soil Conservation Service.

—. 1996a. Livestock and Poultry: World Markets and Trade. Circular Series FL&P 1-96. Washington DC: USDA Foreign Agricultural Service.

—. 1996b. Dairy: World Markets and Trade. Circular Series FD 1-96. Washington DC: USDA Foreign Agricultural Service.

—. 1997. Poultry Production and Value, 1996 Summary. Washington, DC: National Agricultural Statistics Service.

van Hage-Hamsten, M, S Johansson, and S Hogland. 1985. Storage mite allergy is common in a farming population. Clin Allergy 15:555-564.

Vivian, J. 1986. Keeping Bees. Charlotte, VT: Williamson Publishing.

Waller, JA. 1992. Injuries to farmers and farm families in a dairy state. J Occup Med 34:414-421.

Yang, N. 1995. Research and development of buffalo draught power for farming in China. Asian Livestock XX:20-24.

Zhou, C and JM Roseman. 1995. Agriculture-related residual injuries: Prevalence, type, and associated factors among Alabama farm operators, 1990. Journal of Rural Health 11:251-258.

Zuehlke, RL, CF Mutel, and KJ Donham. 1980. Diseases of Agricultural Workers. Iowa City, IA: Department of Preventive Medicine and Environmental Health, University of Iowa.