Laboratory animals

Practical lecture -pharmacology

Handling of animals

Experiments will generally be performed on live animals, and these are to be treated kindly and

handled with care. Animal research is the keystone of medical progress.

Such studies provided the foundation of the current knowledge concerning the functions of the body

The Importance ofAnimals in Biomedical Research

Because of biomedical research both humansand animals now have:• Life-saving surgical procedures;• Cancer therapies;• Organ transplantation;• Vaccines;• Safe consumer products• Treatments and cures for countless other medical disorders and diseases.

The Importance ofAnimals in Biomedical Research

Why are animals used in research?• organs and body systems similar to humans and other animals;• susceptible to the same diseases that affect humans;• short life span allows animals to be studied throughout their entire life;• environment easily controllable to keep experimental variables to a

minimum;

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• Mouse – most frequently used. Pharmacology, genetics of mammals, virology, models of human diseases

• Rat – physiology of cognitive processes, behaviour, models of diabetes

• Rabbit – serology, insulin quantification, pyrogens quantification, tests of irritable effect of chemical substances on the cornea

• Cat – study of CNS and respiratory system

• Dog – e.g. beagle, use in electrophysiology, neurophysiology

• Guinea-pig – in microbiology and serology, physiology of the auditory system

• Hamster - genetics

• Pig – training of surgical techniques

• Primates – chimpanzee – use in neurology, virology, behaviour

• Frog – physiology of blood circulation, electrophysiology

• Fish

The most important species of laboratory animals

MICE:-

Lift the mouse by grasping the caudal end with the right hand and allow it to grip the wire mesh of the cage with its fore legs.With the left hand, grasp the nape of the animal !s neck between the thumb and

index finger. The mouse is now ready for injection.

 

RATS:- procedure for handling is same as mice and can be handled with a minimum of effort or with difficulty, depending on the treatment which they receive. If the rat is treated roughly, it will become

vicious and difficult to handle,

Guinea pig:- is a very tame animal which presents no difficulty in handling. most injections may be

made easily by using one hand to hold the pig firmly against your body. These animals are extremely

susceptible to infection, therefore precaution regarding sterility should be observed during

injections or surgical procedures.

 

Rabbits

rabbits should not be lifted by ears. Grasp the loose skin the nape of the neck with the left hand, the buttocks with the right hand and support the

animal close to your body.

keep in mind that rabbits do not normally utter sound they will only emit cries when in severe

pain*

Signs of Pain and Distress in Rodents

• Decreased activity

• not grooming

• Hunched posture

• Rapid shallow Breathing

• “ Red tears “ albino rats”

• Vocalization

• Feed and/or water refusal

• Weight loss

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GENETICS OF LABORATORY ANIMALS

1.Isogenic = genetically defined strains(isogenicity= genetic uniformity of all individuals)

2.Non-isogenic = genetically undefined strains

3.Genetically semi-defined strains

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SYSTEMS OF BREEDING OF LABORATORY ANINMALS

Open – communication without the barrier

Barrier – the space with the animals is separated from external environment and movements of animals, people and material are controlled to eliminate possible introduction of factors from the external environment (infection) – sterilization of coming water, food, sawdust used for bedding, perfect personal hygiene of the personal.

Isolator – the space for the animals is permanently separated by a barrier from external environment as well as from people who manipulate with the animals.

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Scheme of barrier facility

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Scheme of isolator

Isolators:• overpressure• underpressure

Female Malesex differentiation

Healthy

Mouse

Normal Rat

Normal Mouse Normal

Sick Mouse

Hunched posture Hunched posture

“I’m so proud! All of my kids are going into research”