Physical Hazards Associated With Experimental Animal Care and Use
Many tasks in animal facilities require moderate to heavy physical labour, and performing these tasks may expose personnel to risks from moving heavy equipment (strains), slippery floors, electrical hazards when washing cages, etc. Each person must exercise due caution when performing such tasks. Although the importance of understanding basic animal behaviour in the human/experimental animal interaction to avoid injuries can be emphasized here, it cannot replace the skills that are learned by working directly with the animals. Skilled animal care technical staff will already have the right attitudes and approaches towards animal handling and manipulations. They will also have the practical skills to do so safely and humanely. For others, some of the material presented here can serve as a useful introduction to handling animals safely in an experimental animal facility
To work safely with an experimental animal a person should:
- Understand basic animal behaviour in relation to their interactions with people during handling
- Appreciate the "flight zones" typical of a species
- Understand how to communicate with the animal
- Use appropriate restraint techniques
- Use restraint equipment properly
- Identify any animals that may be unpredictable
- Wear appropriate protective clothing and equipment
- Maintain appropriate vaccination status
Basic Animal Behaviour Related to Handling and Manipulations
The flight zone is an animal's "personal space". The size of the flight zone varies with the tameness of the animal, and other animal-related factors. Completely tame animals have little or no flight zone and a person can touch them. An animal will begin to move away when the person enters the edge of the flight zone. When the person is outside the flight zone, an animal (or group of animals in a herd) will turn and face the person while maintaining a safe distance. It is probably safe to say that when animals are in small cages or pens, all human "intrusions" are inside the animal's flight zone. Therefore, it is very important to condition the animals to regular handling to reduce the apprehension and stress imposed by human presence. When an animal is apprehensive (e.g., about being picked up), aggressive (e.g., about to attack), or defensive (e.g., protecting itself, or its young in the case of a mother), its posture and other behavioural signs can give clues about its state and possible intentions. In many mammalian species the "warning" posture includes lowered head, ears down or back, and in the smaller animals, mouth opens in a snarl.
By carefully observing the animal's behaviour while approaching it, injuries such as bites and scratches can be avoided.
Communicating With the Animal
Your voice, your touch, your smell, are all part of an animal's knowledge about you. To establish a two-way familiarity before a project starts, the people who will be handling or restraining the animals should talk to, touch, and regularly handle each animal. The conditioning period after transport to the laboratory (usually one or two weeks) is an excellent time to begin. Consistency in handling each animal is important. Most laboratory animals learn very quickly who their regular handlers or caretakers are, and accept the handling without undue stress.
Using Appropriate Restraint Techniques
Different species defend themselves in different ways. For example, a mouse, rat, hamster or dog may bite, a rabbit may struggle furiously and kick or sometimes bite to try and escape, a cat may scratch (with intent!) or bite. The approach to restraining the animal, including any equipment used for restraint, is to prevent the animal from taking such action while ensuring it is safely and humanely held. Although the correct approach to handling and restraint can be understood from printed and audio-visual materials, practice is essential. Appropriate handling and restraint methods have been developed for most laboratory animal species. Skills in the appropriate handling and restraint methods should be attained BEFORE the research project starts. (The handling and restraint of non-human primates require special training, equipment and facilities.) For more information see CCAC Guide, Volume 1, 2nd Ed. 1993. Chapter VIII. Occupational Health and Safety.
Use of Restraint Equipment
For some procedures such as intravenous injection in a rabbit, restraint devices or equipment are useful adjuncts to the handling, and help ensure that the procedure can be done safely for both the animal and the person. Correct use of such restraint devices will help avoid unnecessary stress or injury to the animal during the procedure. Conditioning the animal to accept the restraint device is important to minimizing the risk of injury both to the animal and to the handler.
Use of Chemical Restraint
The safe handling of some species either in the laboratory, or in the field, may require the use of "chemical" restraint. Chemical restraint is the use of sedatives or anesthetics to control an animal's activity and thereby allow certain procedures to be done with minimal stress to the animal. Some of the drugs discussed in the Analgesia and Anesthesia modules of this course are useful for chemically restraining animals in circumstances where physical restraint represents a serious risk of harm to the animal or the handler, or is not feasible (e.g., many wild species).
Wearing Appropriate Protective Clothing
Protective clothing suitable for the handling to be done should be worn at all times; laboratory coats, coveralls, gloves, masks, boots (e.g., steel-toed for working with cattle), etc.
Identifying Problem Animals
Any animal known to be difficult to handle should be so identified to all who might be working with it (e.g., weekend staff, veterinarian). As an experienced veterinarian once said, "I've never been bitten by a "biting" dog, but I've been bitten by lots of dogs that didn't bite".
Immunization of Staff
To minimize the risks associated with infections arising from any penetrating wounds such as animal bites or needle sticks, all persons working in laboratory animal facilities should maintain their tetanus vaccination status.
All persons at risk of exposure to rabies from any animals that may be infected should consider vaccination for rabies. Any animals brought into experimental animal facilities that might have been exposed to rabies should be considered risks. Generally this refers to any domestic animals housed outdoors (including farm or fur animals), random source dogs and cats, and any wild animals. Institutions may require staff to have rabies vaccination as a condition of working with such species.
Depending on the species handled (e.g., non-human primates) other immunizations may be recommended as part of a health and safety program. Appropriate records on the vaccination status of all employees should be maintained by the institution.