Mice Intro

Question 1

Are rats of the genus Rattus and mice of the genus Mus bred for use in research covered by USDA regulation

Answer 1

No

Question 2

Are rats of the genus Rattus and mice of the genus Mus bred for use in research covered by PHS policy

Answer 2

Yes

Question 3

Do mice have a gallbaldder

Answer 3

Yes (unlike rats)

Question 4

The red staining around a mouse’s mouth and nose is due to the accumulation of _____ produced by the _______ gland, a lacrimal gland

Answer 4

accumulation of porphyrins produced by the Harderian gland

Question 5

A mouse in a recent shipment of animals appears dehydrated and you want to give SQ fluids. What is the max volume you can give to an average size mouse?

Answer 5

2-3 ml, up to 0.5 ml/site

Question 6

Continent of origin for the lab mouse?

Answer 6

Asia (Old World)

Question 7

The laboratory mouse genome is a mixture of what 2 species?

Answer 7

M. musculus and M. domesticus

Question 8

What is the difference between axenic, gnotobiotic, SPF, and conventional mice?

Answer 8

Axenic- germ free
Gnotobiotic- only defined GI flora, no other bacteria
SPF- specific pathogen free, but normal commensal flora
Conventional- microbes not defined, can have pathogenic organisms

Question 9

What is the origin of the C3H strain?

Answer 9

From a cross of a Bagg albino female and a DBA male by Strong in 1920.

Question 10

What is the color of C3H mice?

Answer 10

Agouti

Question 11

Typical adult mouse weight

Answer 11

20-40 grams

Question 12

Daily water consumption (ml/d) for a mouse?

Answer 12

6-7 ml/day

Question 13

Daily food consumption (g/d) for a mouse?

Answer 13

4-5 g/day

Question 14

Unique traits of murine urine include?

Answer 14

Urine is highly concentrated with large amounts of protein (0.5-1.0 ml in 24 hours)

Question 15

Diploid chromosome number of the lab mouse? (2n= ?)

Answer 15

40

Question 16

Age of puberty for mice?

Answer 16

Puberty ~ 35 days (range 28-49 days)

Question 17

Mice are polyestrous and cycle every ___ days

Answer 17

4-5

Question 18

What is the significance of a vaginal plug in mice?

Answer 18

Denatured seminal fluid and sperm that signifies copulation has occurred.
80-90% of mice with vaginal plugs become pregnant

Question 19

When does the first post partum estrus occur?

Answer 19

12-24 hours after parturition

Question 20

When does the post-lactation estrus occur?

Answer 20

2-4 days post weaning

Question 21

Mouse gestation period

Answer 21

17-21 days

Question 22

Describe the number and location of mammary glands in the mouse.

Answer 22

5 pair of mammary fat pads just below the skin. 3 thoracic, 2 inguinal
Each has exterior nipple

Question 23

Cohoused male mice may fight. Typical fight injuries occur on which parts of the body?

Answer 23

Scrotal area, base of tail

Question 24

C57BL/6 mice are predisposed to what dermatological condition?

Answer 24

Idiopathic (ulcerative) dermatitis

Also barbering

Question 25

What the genus and species anme of the two major fur mites seen in lab mice?

Answer 25

Myobia musculi and Myocoptes musculinus

Question 26

Name the genuses of two common types of pinworms seen in mice.

Answer 26

Syphacia, Aspicularis

Question 27

Ringtail is associated with what environmental condition?

Answer 27

Low relative humidity

Question 28

Dental formula for mice

Answer 28

I 1/1 C 0/0 P 0/0 M 3/3

Question 29

Describe the approach for an IP injection in mice.

Answer 29

Lower right abdomen, between midline and hind leg

Question 30

Why are IM injections not recommended in mice?

Answer 30

Small muscle volume, injection can cause muscular atrophy, nerve damage

Question 31

Name six sites for blood collection in mice.

Answer 31

``` Medial saphenous vein Lateral saphenous vein Lateral tail vein Submandibular Retroorbital Cardiac exsanguination ```

Question 32

Name 4 sites that are acceptable for blood collection awake in mice

Answer 32

Medial saphenous vein Lateral saphenous vein Lateral tail vein Submandibular

Question 33

Ear punches or ear tags used for ID in mice should be placed where on the ear?

Answer 33

should be placed approximately 3 mm from the edge of the ear pinna.

Question 34

What 2 anatomical sites are commonly tattooed for individual mouse identification?

Answer 34

Tails and footpads

Question 35

When is toe clipping an acceptable means of identification in mice?

Answer 35

Only used when no other individual identification is feasible. 2011 Guide

Question 36

At what age should tail ampuation for mouse genotyping occur?

Answer 36

2-3 weeks of age

Question 37

What is the maximum amount of tail that should be amputated for genotyping?

Answer 37

2 mm

Question 38

How allometric scaling of drug doses performed?

Answer 38

Based on estimation of basal metabolic rate (BMR) BMR = k(Wkg0.75) Wkg= body weight in kilograms k= “species factor”

Question 39

Which "old school" anesthetic is associated with peritonitis and a dynamic ileus?

Answer 39

Choral hydrate

Question 40

Which "old school" anesthetic is carcinogenic and, thus, unsuitable for survival surgeries?

Answer 40

Urethane

Question 41

This "old school" anesthetic was sold under the proprietary name Avertin and decomposes into irritating and toxic products if stored at room temperature and exposed to light?

Answer 41

Tribromoethanol

Question 42

Major disadvantages of pentobarbital for anesthesia?

Answer 42

Controlled (CII), poor analgesia, risk of perivascular necrosis

Question 43

According to ______'s Law a small change in airway diameter leads to big changes in airway resistence.

Answer 43

Poisseille's Law

Question 44

Reducing the airway diameter of a rodent by 1/2 by ET tube placement, increases the resistance by how much?

Answer 44

16x

Question 45

What important consideration is essential for intubated small mammals?

Answer 45

Must be on ventilation

Question 46

Define major surgery

Answer 46

Major –“penetrates and exposes a body cavity, produces substantial impairment of physical or physiologic function, or involves extensive tissue dissection or transection”

Question 47

Define minor surgery

Answer 47

“does not expose a body cavity and causes little or no physical impairment”

Question 48

True or false: aseptic techique in rodents requires the use of a sterile gown and gloves.

Answer 48

False, but tissue handling should be done with sterile istrument tips

Question 49

What is the most appropriate method for monitoring depth of anesthesia in rodents?

Answer 49

Toe pinch test –firm pinch of the foot or toe should not elicit any movement in an adequately anesthetized animal

Question 50

Which rodent spp should not have anesthetic depth assessed by the toe pinch method?

Answer 50

Guinea pigs, toe pinch reflex present at surgical planes of anesthesia

Question 51

What is the grimace test in mice?

Answer 51

A pain assessment tool