Basic Animal Care

A. GENERAL PRACTICES

1. Reception

The portal through which animals and containers enter a facility is important in the overall prevention of disease. The examination of newly arrived animals should have several aims: evaluating the condition and health of the animals; preventing cross-contamination of animals from different sources; and ensuring that the order has been accurately filled. The health status of the animals at their source and the possibility of cross-contamination during transport are important considerations. Cross-contamination is always a greater risk if the animals are not shipped in a vehicle dedicated to the transport of animals, coming from a single source. However, this risk can be decreased by the use of filtered shipping crates.

Each new shipment of animals should be received, uncrated and examined by trained personnel and placed in clean cages in a designated reception area separate from the animal holding room(s). The reception area should be cleaned and disinfected after each new shipment. Shipping containers should not enter the main facility unless properly decontaminated and should be properly disposed of, or thoroughly cleaned and disinfected if they are to be reused. Incoming animals should be identified and their arrival appropriately recorded. 

Animals that appear unhealthy, or which have been in any way debilitated in transit, should be separated from the remainder and held in an appropriate location for observation and treatment. Where this is not feasible, such animals should be euthanized without delay. 

Cell lines should be shown to be free of specific organisms before they are injected into disease-free animals.

2. Conditioning/Quarantine

Quarantining is most important as it allows detection of disease prior to introduction to a disease-free colony. The level of conditioning required will depend on the differences in microbial status between the resident animals and the incoming animals. Rodents are commonly purposebred for the laboratory and can be received from the supplier in a defined state, with a known health, nutritional and, to a varying extent, genetic background. Similarly other purposebred species obtained from reputable sources will have complete health profiles and will have received specified prophylactic treatment. Such animals may not normally require further quarantine for confirmation of their health status; however, a holding period of several days will give the animals the opportunity to adjust to their new surroundings. A minimum adjustment period of two days is required after shipping for immune function, corticosterone levels and other physiological parameters to stabilize. 

Legally procured strays or donated animals, acquired feral animals, such as non human primates, and animals from other random sources should be subjected to a period of conditioning following their reception. Conditioning requires that the animal be held for a varying period of time (1-6 weeks) in separate quarters. The length of the conditioning period will depend on the species, the health status of the animals, the reliability of the supplier, and whether an active process of screening animals for the presence of or exposure to infectious agents is undertaken. During this period, thorough physical examinations should be undertaken. Further examination will depend on species and intended use. 

The conditioning period should be of sufficient duration to permit the proper evaluation of the suitability of the animal(s) for their intended use, and testing for contagious, zoonotic and other diseases that may be of concern. This can include serological screening for antibodies to viruses and other pathogens, the examination for ecto- and endo-parasites, mycoplasma, and pathogenic bacteria. If contamination during transport is a possibility, an appropriate period to allow expression of disease or antibody production should be allowed. Sufficient time must also be allowed for appropriate treatment or vaccination against diseases that tend to be endemic in the species being conditioned. 

During the conditioning/quarantine period, the animals should be held in facilities separated from other animals with no crossover of personnel, equipment, supplies or ventilation, unless effective measures are taken to prevent cross-contamination. Wearing facility-specific protective clothing helps keeping animals free of infectious disease.

3. Holding (Maintenance)

Only one species should be housed in a conventional animal room unless maintained in isolator caging, racks or cabinets. Shipments of the same species, acquired from different suppliers, should also be separated according to health status if space permits, or housed in isolator caging. Where the mixing of species and/or stocks from different sources is unavoidable, every effort should be made to place together those that are behaviourally compatible, have similar environmental requirements, and a low probability of cross-infection. Non human primates should not be housed with any other species. 

HEPA (High Efficiency Particulate Air) filters are often used in animal facilities to filter out all the particles in the air down to tenths of a micron in diameter. 

Animals should be held in enclosures adequate for that species as described in the CCAC’s Guide to the Care And Use of Experimental Animals, Volume 2.

4. Identification and Records

Cage or group identification may be used for small laboratory animals if individual identification is not an experimental prerequisite. Individual identification can be by ear tagging, ear notching, tattooing, tail marking, subcutaneous microchip implant or other species appropriate method. Dye marking on the hair provides for short-term identification. Larger laboratory animals should always be individually identified by tattoo, neck band, individual tag, or a subcutaneous identity tag. 

The Canadian Council on Animal Care (CCAC) opposes the use of toe clipping as a method of identification for the short-term learning experience of field studies. Where it is necessary to provide permanent individual identification between litter members of newborn rodents, toe clipping may be necessary. If, for any reason, this procedure has to be undertaken on other than neonatal animals, either a local or general anesthetic should be administered. 

The importance of keeping complete and thorough records on all experimental animals cannot be overemphasized. Monitoring of the animal's health and of the experiment's progress usually depends on knowing which animal is which. The following information should be recorded for each animal: arrival date, sex, estimated age and weight, breed and type, colour and markings and any physical abnormalities or other identifying features. The name of the project or investigator and protocol number to which it is allocated should be noted, as well as that of the supplier and eventual disposition. Animal records should be kept for a period of one year after the final disposition of the animal. The cages in which animals are housed, prior to or during an experiment, should be clearly marked indicating the sex and number of contained animals, the investigator responsible for them and such special instructions as may be pertinent to their care. Records, especially when used in conjunction with data processing equipment, can facilitate facility management. 

Use of room cards/boards on the doors of animal rooms indicating the species, investigator(s) whose animals are being held and any special notations that may be pertinent is a good practice. 

People donating animals to research facilities are required to sign a statement that they are the legal owner. This document should include identification of the animal by the criteria previously noted, and should specifically transfer ownership and disposal of the animal to the institution. Animals (such as dogs, for which a system of national registry exists) should always be checked for the presence of identifying markings. 

 

B. CARE OF THE ANIMAL

1. Food

All experimental animals should receive palatable, wholesome and nutritionally adequate food according to the requirements of the species, unless the study requires otherwise. In certain experiments where small quantities of chemical residues may influence results, certified diets with documented analysis of contaminant pesticides, herbicides, etc., are available from commercial manufacturers of laboratory animal diets.

a) Food Storage

Whenever possible, pasteurized or sterilized diets obtained from reputable suppliers should be used. Proper storage of foods is necessary to minimize the possibility of contamination, deterioration or spoilage. Dry laboratory animal diets should be used within six months of the milling date when stored in cool, dry, well-ventilated quarters. Irradiated diets kept under the same conditions have approximately double the shelf life. Primate and guinea pig diets should be used within three months of the milling date, unless vitamin C is supplemented. To avoid problems from age deterioration, the date of milling of each shipment should be obtained from the supplier (this is usually marked in code on the bags). Bags should then be marked, put on plastic or metal pallets or racks to keep them off the floor, and stored so that the oldest will be used first. Stale shipments should not be accepted. Shelf life will be appreciably enhanced if the storage area is maintained at a temperature of <16C (60.8F). Canned foods can be safely stored for long periods. Clean green vegetables suitable for human consumption may enhance the diet; however, vegetable discards may prove sources of infection and should be avoided. 

Food used in microbe-controlled environments is often autoclaved. Autoclaving decreases the concentrations of some vitamins and antioxidants. However, autoclavable diets are available which contain higher concentrations of heat-labile ingredients to compensate for the losses induced by heat-sterilization. Shelf life may be decreased, but need not be if the process is handled properly. Gamma irradiation is also used for diet sterilization. 

Diet in large quantities should not be stored in animal holding rooms. Small quantities, sufficient for one or two days may be kept in the room in covered, vermin-proof containers.

b) Special Considerations

All animals tend to reduce their food intake when sick. Animals with a high metabolic rate, e.g., small rodents and those requiring fairly frequent feedings of high protein diets (e.g., the cat), can become debilitated very rapidly. In cases of anorexia in these species, oral intubation and force feeding as well as intravenous therapy (cat) should be instituted without undue delay. Restricted feeding for maintenance of adult animals is commonly practiced for some species and strains, such as rabbits. Animals on restricted food or fluid intake for experimental purposes should be closely monitored for weight loss, signs of dehydration, signs of stress and deterioration in health. It should be noted that food and water restriction may have a marked effect on the response of animals to toxic substances and other experimental variables. For some species, particularly non human primates, providing a variety of foods can be useful as a form of environmental enrichment. 

Generally, food should not be scattered over the bottom of the cage, where it may be contaminated or wasted. Exceptions to this include provision of food to newly hatched birds and abnormal (handicapped) animals, such as mice with muscular dystrophy.

2. Water

Drinking water should be available to animals at all times, unless contra-indicated by the experimental protocol. Tap water, even if from municipal water systems, is not sterile and quickly becomes contaminated with even more bacteria after the bottle is placed on the cage. Monitoring water quality is an important aspect of any research program, as water contamination and chemical composition can affect the health of animals and the results of animal experiments. 

Methods available to remove both microbial and chemical contamination include acidification, chlorination, reverse osmosis, ultrafiltration and ultraviolet (UV) light. Some of these methods may alter immune function and growth rates in experimental animals. Regardless of whether or not the water supply is treated, all water dispensing equipment should be thoroughly sanitized according to institutional SOPs, and periodically monitored for bacterial contaminants. 

A watering method unlikely to spread disease or contaminate the water supply should be chosen. Water bottles should be transparent so as to permit ready observation of cleanliness and water level; of a material that will withstand sterilization, and of a wide mouth design to facilitate cleaning. Water bottles should always be replaced with clean, freshly filled ones, rather than by refilling the ones in use. Animals housed under freezing conditions may require heated water bowls. 

Automatic watering devices are economical to operate, but if not properly designed, are difficult to disinfect properly and may lead to cross-contamination. Recirculating systems eliminate stagnation of water and help prevent buildup of microorganisms. The correct pressure in the drinking valves prevents backflow of water into the lines when animals drink from or play with the valve. Malfunction of automatic watering systems can lead to drowning or drought; consequently, the system must be routinely and thoroughly checked. Some animals need to be taught to use automatic watering devices. Automatic watering devices are not recommended for guinea pigs, unless they are habituated to them. 

Most fish have a low tolerance for both copper ions and chlorine. Their water supply, therefore, should either be dechlorinated or obtained from an untreated source, and should not be brought into the aquarium through copper piping.

3. Exercise

Experts disagree about the need for exercise in laboratory animals. A judgment in such cases must thus be made by the laboratory animal veterinarian in consultation with the investigator. Although many adult animals do not seem to have a motivation to exercise per se, in the process of satisfying their behavioural needs, they do get exercise. Exercise requirements for animals should reflect species, age and environment. Research information on the requirements of each species for exercise is limited and varied, but continually increasing. Young animals of most species involve themselves in much more play and exercise activity than adults. For some species, exercise may not be required in adult animals for physiological health. Several studies suggest that there are no beneficial effects on behaviour, health or in enhancement of voluntary activity in the laboratory-bred beagle from increasing the cage dimensions beyond the standard 76 cm x 76 cm x 76 cm (30" x 30" x 30") size, provision of half-hour daily exercise, or from 1.22 m x 3.05 m (4' x 10') floor pen housing. Judgment should be based on the animal's breed, temperament, physical condition, the conditions under which it has previously been kept and the length of time it is to be confined. Animal cages must, however, always be large enough to allow the innate normal behavioural and postural adjustments. There are many varied methods and programs of exercise which are successfully used in dogs, including walking programs using outside volunteers. Caged rats spontaneously exercise by playing with cage mates and during feeding.

 

C. CARE OF THE FACILITY

1. Cleaning and Sanitation

Employees must be aware of proper cleaning and disinfecting procedures and their importance in disease prevention. All cages, pens, racks, aquaria, accessory equipment, etc., must be thoroughly cleaned and disinfected before reuse. Most of these items should be subject to regular (usually weekly) cleaning during use. As a general rule, laboratory animals should be moved to freshly cleaned cages at least once a week. Cleaning practices need to be modified according to the species and housing system for domestic animals, fowl, reptiles and aquatic animals. The effectiveness of detergents, disinfectants and facility cleaning programs should be monitored and constant.

The ability to clean and sanitize a facility is greatly influenced by facility design and construction materials. The objective of a sanitation program is to reduce the microbial contamination or "bioburden" to a level that reduces the possibility of any cross-contamination. Proper sanitation will not compensate for the transfer of infection by personnel. Cleaning and sanitation merely complement proper procedures which minimize contamination. Activities such as pressure spraying and dumping bedding can aerosolize microorganisms allowing cross-contamination if animals are present. Opening doors can alter the airflow in a facility, enhancing the possibility of transfer of contaminants. Moveable equipment can transmit organisms between areas. Therefore, such equipment should be dedicated to a particular room or area.

Procedure rooms using animals from different sources are a potential source of cross-contamination. Proper disinfection of surfaces should be ensured after use.

Bedding in animal cages or pens should be changed as often as necessary to keep the animal clean, dry, and relatively odour-free and ammonia levels in the cage at appropriate levels. In rats, this is 25 ppm. Smaller laboratory animals require one to three changes per week, depending on such variables as the sizes of the animals, population density and type of caging and whether or not litters are being produced. Larger species such as dogs, cats and non human primates usually require at least a daily change.

Food containers should be easily cleaned and disinfected.

Animal cages are most efficiently cleaned and sanitized with mechanical washing equipment operating at 83C (180F) or higher, for a minimum of ten minutes. Cages should be carefully rinsed to remove all traces of washing and disinfecting agents, as exposure to these may adversely affect both the animal and the experimental results. All automatic washing equipment should be subjected to regular maintenance to assure proper performance. Where an automatic cagewasher is not available, use of a spray washer and disinfectant are preferable to the dip tank and rinsing method. It should be noted that sodium hypochlorite and iodophores are effective on most animal viruses; however, disinfectants should be chosen according to the spectrum of viruses and organisms required to be killed and the possibility of deactivation by the local environment. There are references available to aid in identification of the appropriate disinfectants. Chlorine dioxide sterilants/disinfectants have become more recently available and are often used in facilities maintaining SPF or immunosuppressed animals because of their rapid broad spectrum activity, even in the presence of an organic load.

All chemicals should be used properly, according to label directions. Detergents, disinfectants and pesticides may cause changes in the experimental animal by inducing or inhibiting cellular enzyme activity. This should be a consideration when conducting experiments which may be adversely affected.

2. Waste Disposal

Dead animals, animal tissues and excreta, bedding, unused food, etc., should be collected in leak-proof metal or plastic containers with leak-proof, disposable liners and tight lids. Liners are essential for animal tissues, carcasses, and radioactive or toxic waste. Infectious waste should, ideally, be incinerated on the site. If the waste is to leave the facility it should be sterilized (autoclaved) before removal. Gamma irradiation is a relatively recent method of disinfection of waste products which may come into more prominent use.

Waste which cannot be rapidly disposed of should be stored in a cold storage area provided for that purpose. Such areas must be vermin-free, easily cleaned and disinfected as well as being physically separated from other storage facilities. The waste storage area should be located so that wastes need not be carried through other rooms of the facility.

Dead animals should be removed from cages as soon as they are noticed. The laboratory animal veterinarian who should have been immediately informed of sick animals, should also be informed of dead ones. Dead animals should be properly identified, placed in disposable plastic bags and taken to the postmortem area immediately upon discovery. In the postmortem area they should be held under refrigeration for necropsy or for disposal in accordance with the investigator's instructions. National guidelines as well as local and provincial laws control waste disposal practices that could endanger public health.

Considerable forethought and extensive consultation is advisable before installing an incineration facility for the disposal of pathological waste.

3. Vermin Control

A properly constructed building should be vermin-proof, but may not be free from vermin. Vermin enter on food, bedding, people and animals. Insects and arthropods thus introduced, may act as the intermediate hosts of certain parasites and may also mechanically transmit bacterial and other pathogens. Wild rodents may transmit a wide variety of bacteria, viruses, and parasites to caged members of closely related species. New facilities should be checked critically for vermin before any animals are moved in.

Vermin should also be controlled in already-infested older buildings. A control program will include the proper training of personnel, good waste disposal, sealing or eliminating breeding sites, extermination through pesticides or trapping, and the recovery of all escaped and/or wild animals. It is important that pesticides be applied only under professional supervision. Many pesticides are dangerous to humans, and may adversely affect the experimental animal and the research. Any control program that is initiated must extend throughout all areas of the facility, with special attention to food and bedding storage. The practice of using a free-roaming cat for the control of wild and escaped rodents is not acceptable except in farm animal facilities, and only under close management.

If insect colonies are kept in or near an animal care facility, there must be regular monitoring of the facility against infestation from escapees. Such insect colonies should be kept behind a screened enclosure or inside an escape-proof container. The use of insecticides must also be compatible with these insect colonies.

4. Holiday and Emergency Care

  1. Weekend and Holiday Care of Laboratory Animals is Essential. It should be recognized that changes in personnel and feeding and cleaning schedules, as can occur during these periods, are known to be stressful to routine-oriented animals.
  2. Animal Care is a Continuous and Daily Responsibility

This point should be emphasized in job descriptions for animal care personnel and in union contracts. Basic animal care should be categorized as an "essential service" and a clause to this effect should be included in all collective agreements, and should not be subject to interruption through strike action. Staff must be provided for weekends and holidays, and skilled assistance must be available in the event of an emergency.

The names and telephone numbers of staff responsible for the animals should be given to security personnel. Some institutions may also choose to have contact telephone numbers posted prominently in the facility. In either case, directions for contacting responsible animal care staff must be made available in the facility. All the animal care staff should be informed of their responsibilities in emergency situations.

Where employees are unionized, the CCAC suggests an essential services provision to be inserted near the strikes and lockouts clause for the designation of employees to care* for research animals. The parties must agree that proper care of all research animals will be maintained by the members of the bargaining unit in the event of a strike or lockout in the course of the agreement or its continuance.

At least seven days before the commencement of a strike or lockout, the employer will designate and identify a number of employees which it deems sufficient to provide for continuous proper care of the animals during the strike or lockout. A list of the names must be delivered to the Union and the parties agree to meet with a view to executing a formal agreement with respect to the employees affected. Should the parties be unable to reach agreement on the persons to be designated, the matter will be referred to the CCAC, for final and binding resolution by the Council.

All persons so designated must be paid their regular salary during the period of designation.

Due regard should be had for previously arranged vacations and other matters and as far as possible the designated duties will be dispersed among all appropriate employees equally. No other duties will be assigned to these designated employees.

* Proper care implies provision of appropriate temperatures, humidity, light cycles, ventilation, food, water and cleaning as well as exercise and nursing care where appropriate

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