PRACTICAL 1 HANDLING & RESTRAINT OF LAB ANIMALS
General principles in animal handling and restraining:
Proper restraint and handling techniques reduces stressHandling stress represents an experimental variable
Animals can inflict serious injuries to humans and to themselves
Acclimatization:
Animals experience stress as a result of shipping
- all large animals are acclimate to the facility for 3 days
- they may not be experimentally manipulated during this time
- acclimation period >1 week recommended for all animals
If a study will involve handling of animals, it is recommended that the animals be acclimated to the handling
- prior to experimental manipulation, handle the animal on a regular basis in a non-threatening situation: weighing, petting, giving food treats
- most animals even rodents will respond positively to handling & will learn to recognize individuals
Mouse (mencit) - Mus musculus
biological characteristics:
very acute hearing
well developed sense of smell
poor vision
small size
short generation interval
most common lab animal for research
Rat (tikus) - Rattus norvegicus
biological characteristics:
acute hearing - sensitive to ultrasounds & high pitched sounds
poor vision - unable to detect color
tail is the principal organ for heat exchange
Precautions during handling:
Handling gently without making loud noises/sudden movements that may startle them
Handling firmly as animal will struggle more if see chance to escape
Use restraint devices to assist when appropriate
Use an assistant whenever possible
Chemical restraint for any prolonged/potentially painful procedure
Physical restraint:
Use of manual or mechanical - to limit some or all of an animal's movements for the purpose of examination, sample collection, drug administration, therapy and experimental manipulation
Animals are restrained for brief periods, usually minutes, in most research applications - restraint devices should be suitable in size, design, operation to minimize discomfort & injury to the animal
Methods of physical restraint:
Tail
- adequate for examining & transferring to other cage
Forceps
Scruff: one hand/2 hand
Mechanical: plexiglass, plastic bags, devices
Handling & restraint of mice:
Grasp the middle of tail btwn your thumb & index finger & lift
Grasp the scruff/middle of the tail btwn the thumb forcep & apply on enough pressure to lift the mouse - too much pressure may cause pain/crush the tail
Place the mouse on a rough surface/on cage lid while hold the tail firmly & lift the mouse
Smooth surface will frighten the mouse because it cannot get a foothold - may cause it to turn around & try to bite in its attempt to escape
Grasp the loose skin behind ears gently by thumb & forefinger while maintain grip on tail
As soon as the mouse head restrained, the mouse can be picked up & the tail secured within your ring finger & little finger
These methods may be used to perform minor, non-painful procedures: injections/ear tagging
Handling & restraint of rats:
Grasp the base of tail & place on a firm surface
Encircle the body over shoulder & neck region with the other hand
Once the head & body are secured, the rat may be lifted
If grasp too tight, animal's respiration can be compromised
Handling & restraint of rabbits:
Rabbits have a delicate skeletal system - can be easily damaged if not handle properly
They have powerful hindquarters used for kicking
Remove from cage:
Grasp the scruff of fur behind neck firmly with dominant hand
Lift gently while scooping under the hindquarters with other hand & remove from cage
Transporting:
Scruff the rabbit by the neck
Place rabbit's head under your arm btwn elbow & ribcage & allow rabbit to rest on lower arm, supporting the rump with same hand
Place other hand on rabbit's dorsal surface to maintain control
Hypnotism: only for minor procedures, nail trims not for painful procedures
Grasp the scruff firmly with dominant hand
Cross the non-dominant hand underneath to scruff the rump
Quickly put the rabbit on its back & transfer the rump hand to the abdomen
Gently stroke the rabbit's abdomen until nictating membrane (third eyelid) moves over the pupil
Check pedal reflex
If hypnotized, rabbit will not move
Towel wrap:
Place the rabbit on an open towel on a flat surface & snugly wrap it into a bunny burrito
Gently pull out the part you need to examine
Be careful to not let it overheat
Characteristics of a good restraint device:
prevent animal from turning around, yet allow easy access to the tail or legs
easy to clean
provide adequate ventilation
does not cause injury
Rabbit: use the type with correct size to avoid injury
Sexing mice/rats: distance between anal & genital orifices: male>female
Sexing rabbits:
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