This document discusses common laboratory animals used in drug development research. It begins by introducing the importance of animal models that share physiological and anatomical similarities with humans. It then classifies disease models and research types that utilize animal subjects. The majority of the document focuses on describing specific rodent animal models commonly used - rats, mice, guinea pigs, gerbils, and hamsters. Details provided include typical strains, applications in research, anatomical features, life cycles, and other relevant information. A brief overview of non-rodent models like rabbits, monkeys, cats, and dogs is also presented.

1. Common laboratory animals used in Drug
Development
Part - I
Dr. K. Manohar Babu
VJ’s College of Pharmacy
Rajamahendravaram

2. Contents
Types of animal models
Classification of disease models
Classification based on research
Rodent Animal Models
Rat
Mouse
Guinea Pig
Gerbil
Hamster
Non Rodents
Rabbit
Monkey
Cat
Dog
Miscellaneous
Frog
Zebra Fish
Chicken
Pigeon

3. INTRODUCTION
Physiologically and Anatomically there is a similarity
between the humans and animals at organs and organ
systems, which function in a similar fashion.
This similarity makes animals ideal models for the study
and development of products and techniques for humans.

4. Homologous
animals:
same causes,
symptoms and
treatment
options as
would humans
who have the
same disease
Isomorphic
animals:
share the same
symptoms and
treatments
Predictive
Animals:
when animals
strictly display
only the
treatment
characteristics
of a disease.

5. CLASSIFICATION OF DISEASE MODELS
1. Induced (experimental) disease models
2. Spontaneous (genetic) disease models
3. Transgenic disease models
4. Negative disease models
5. Orphan disease models

6. Classifications of animal research
Animal research are of following types:
Basic research.
Applied research.
Toxicology testing.
Xeno transplantation.

7. Animals used
in Research
Mammals
Rodents
Non Rodents
Miscellaneous
Mice, Rat, Guinea pig, Hamsters
Rabbit, Dog, Cat, Monkey
Pigeon, Zebra fish, Chicken

9. Rodent Animal Models
 Rat
 Mouse
 Guinea Pig
 Gerbil
 Hamster

10. Rat(rattus novergicus)
Strains of rats used in experimental pharmacology are
wistar strain, sprauge-dawley and porton.
Rats resemble humans in several organ function, nutrition and sensitive to
most of the drugs, make them very use full in experimental pharmacology.
The various tissues used for the study of drugs are colon, stomach, uterus,
ceacum, vas deference and abdominal smooth muscle.
Rat brain tissue is extensively employed in radio-receptor ligand studies.

11. Anatomy
• Absence of gallbladder
• Open rooted incisors
• Extensive mammary
tissue
• Harderian gland behind
eyeball secrets
porphyrin
• Average weight 350g

13. Wister Rats
Developed in Wister Institute in 1906
Wide Head
Long ears
Tail length is lesser then body length
SPRAGUE DAWLEY RATS
These rats typically have increased tail to body
lengthratio as compared to Wister Rats

16. Gestation : 21 days
Weaning : 21 days
Estrus : 4-6 days
Sexual maturity
Females : 6 weeks**
Males : 8 weeks
Lifespan : 2-3.5 years
Chromosomes : 22 pairs

17. Why rats can’t vomit ?
they can't wrench open the esophageal sphincter.
– esophageal sphincter is opened during vomiting with the
help of the longitudinal muscle of the esophagus. Weak
in rat.
rats lack the necessary neural connections to
coordinate the muscles involved in vomiting.
– Brainstem nuclei and the muscle systems used in
vomiting, rats don’t have complex connections between
the nuclei or between the brainstem and the viscera that
are required for such a coordinated behavior. E. g Rat,
mouse, guinea pig, rabbit

18. Mice(mus musculus)
Strains of mice used in experimental pharmacology are Swiss strain, Laca
andBalb/c.
They are small in size (25-30gms) and extensively used in toxic study,
bioassay of drugs(insulin), testing of analgesics, CNS active drugs and
chemotherapeutic agents.
Most recently mouse brain tissue as well as primary cell culture of mouse
spinal cord neurons are used in neuropharmacology for studying
neurotransmitter receptor functions.

19. Anatomy
• Porphyrin Glad behind eyeball
• Small size 25-40 grams
• Open rooted incisors
• Males have larger spleen than females
• Extensive mammary tissue

20.  Mouse Lifespan : 1-3 years
Gestation : 21 days
Weaning : 21 days
Sexual maturity
Females : 6 weeks
Males : 8 weeks
Estrus : 4-6 days
.

21. Guinea pig(cavia porcellus)
Guinea pigs (400-600gms) are the commonly used experimental animals.
They are used to study local anesthetics, and as a models in experimental
amoebiasis and cholera as they are sensitive to these microorganisms.
Guinea pig tissues such as ileum is the most common preparation used to
study spasmogen and antispasmodics.

22. Vitamin C cannot synthesize their own. Must be supplemented
Serum of Guinea pig contain enzyme Aspariginase which shows
Anti leukemic action
Guinea pig needs high levels of Folic acid, Thiamine, arginine and
vitamin K – good model for nutritional deficiency
Serum containing natural pain killers known as enkephalins
Plasma of Guinea pig contain low density lipoprotein- useful in
cholesterol metabolism
Guinea pig gestation period 59-72 days– useful to study birth
effects
Useful in development vaccine for diphtheria, Tuberculosis
Bio assay of Digitalis
Allergic reactions and Asthma
Histamine and Antihistamine drugs screening
Guinea pig Use in research

24. Two Species are commonly used
Golden or Syrian hamster
Chinese hamster
 Their cheek pouches do not have lymphatic drainage-
hence ideal sites for tissue transplantation
 Hamsters live an average 18 to 24 months and have a
gestation period of 16 days.
 Used in Oncovirus, Infuenza virus