1. Introduction to common Laboratory Animals
Division of Laboratory Animal Science.

2. RODENTIA
3 suborders
A. Myomorpha- Mouse like (Rats, Mice, Hamsters etc.)
B. Sciuromorpha - Squirrel like
C. Caviomorpha- Guinea pigs, Capybara (Largest rodent-66kg)

3. Mouse- Mus musculus Class- Mammalia Order- Rodentia
Chromosome number-(2n)- 40
Blood volume (ml/ 100 gram)- 6ml
Olfaction highly developed.
Poor vision
Large S.A/ gram body weight- So dramatic physiologic changes in response to ambient temperature.
Length of tail= L. of body

4. Contd. Heart rate= 300-800 bpm Body temp.- 36.5-38.0 deg C.
WHITTEN Effect:- synchronisation of estrous of a group of females when a male is introduced.
BRUCE Effect:- After a successful mating, within 24 hrs, if female is housed with a second male, implantation is prevented and comes to heat in 4-5 days.

5. Contd.
LEE-BOOT Effect- Group of females housed together becomes anoestrous or pseudopregnant.
STRAIN- Inbred colony
STOCK- Outbred colony.
Eg; of mice strains are- BALB/c, C57BL, C3H, nude/ Athymic mice etc.
Mice are used in acute systemic toxicity studies, L.D.50, E.D.50 etc.

6. Rats- Ratus norwegicus
2n Chromosome number= 42.
Thermoregulation centre matures 2 weeks after birth- Since then, Cuddling of new born animals.
Rats regulates its own body weight and food intake.
Strains
Wistar came first – Wistar laboratories
Sprague Dawley- From Wistar x Unknown wild by R.W.Dawley of Wisconsin.

7. Contd… Long Evans hooded- W x Wild male
SHR- From Wistar Kyoto by truncation selection process.
Rats are used in

8. Hamster- Mesocricetus auratus
Chromosome number- (2n)- 44
Cheek pouches present- Tumour research
Hibernation
Short day, Low temp., Solitude, adequate food, nest etc. induces hibernation.
Golden/Syrian hamster- Commonly used, Chinese hamster

9. Guinea pigs- Cavia porcellus.
2n Chromosome number is- 64
5th most used lab species (Mice>Rats>Birds>Fishes>Guinea pigs>G.P)
Most fragile among lab animals
Maximization sensitization tests

10. Rabbits- Oryctolagus cuniculus
Stocks- Outbred
New Zealand white, Soviet chinchilla, Silver fox etc.
Pyrogen testing
Intracutaneous irritation tests
Bone implantations for orthopaedic implants

11. THANK YOU