Mice Flashcards
Scientific name for mice
Mus musculus
Order of mice
Rodentia
Family of mice
Muridae
Most common color of mice in research
Albino
4 Strains of mice genetics
- Outbred
- Inbred (isogenic)
- Congenic
- Transgenic
Result from random mating to achieve genetic variations to represent the diversity of human population
Outbred strain
Result of brother/sister, father/daughter, mother/son matings for a minimum of 20 consecutive generations
Inbred strain
Animals are genetically different at a specific locus
Congenic strain
The result of microinjection of DNA into mouse eggs for the production of very specific disease models
Transgenic strains
2 Most common strain of mice used in research
BALB/c and C57BL
Used in research more frequently because they are nicer
BALB/c
5 ecological types of mice
- Germ-free/axenic
- Gnotobiotic
- Specific pathogen free
- Conventional
- Sentinel animals
Ecological type that is free of ALL detectable microflora that must be housed in special circumstances and diets
NO MICROFLORA
Germ-free/axenic
Ecological type that is Associated known microflora
Gnotobiotic
Ecological type that is free of specific pathogens and has normal flora
Most common used in research
Specific pathogen free
Ecological type that is animals with undefined microflora and housed with no special precautions
Mostly pet store animals
Conventional
Ecological type of healthy animals placed in a room with other animals as a means of detecting the presence of a dz
AKA “surveillance animals”
Sentinel animals
Why are mice used more than any other animals in research? (7)
- Short life span
- Short gestation
- Lg. litter sizes
- Great genetic diversity
- Inexpensive
- Easy to maintain
- Good models for toxicity tests
Have a tendency to fight when they hit puberty, so should be housed alone
Males
When a dominant mouse in a group will remove the facial hair from all other mice in the cage
Barbering
Nice are active at night, so they are considered
Nocturnal
Most common cage type used
Shoe box cage
A cotton square mice can tear apart to keep them mentally stimulated and they can use as a nest
Nestlet
Mice have highly developed senses of
Smell and hearing
A mouse’s sense of _____ is not highly developed
Sight
Average life span of a mouse
1-3 yrs
The average body temp of a mouse
98-101 degrees F
Average HR of a mouse
300-750 BPM
Average RR for a mouse
70-120 RPM
Average gestation of a mouse
19-21 days
Average weaning age of young mice
21-28 days
How to properly restrain a mouse
Lift by the base of the tail and do a full body scruff
When picking a mouse up too far towards to end of the tail, it may result in this type of injury
Degloving
Rodent teeth are considered
Hypsodontic
The color that rodent teeth turn when they age
Yellow/orange
________ may occur, so clipping/cutting the teeth may be necessary
Malocclusion
2 functions of a mouse’s tail
Balance and thermoregulation
2( I 1/1, C 0/0, P 0/0, M 3/3)
Rodent dental formula
Most common neoplasia seen in mice
Mammary tumors
How many mammary glands do mice have?
5
________ are more prominent in females
Nipples
Makes have _________ _________ to retract their testicles. They must be closed during neutering.
Inguinal canals
Rodent teeth are __________, meaning they continuously grow.
hypsodontic/open rooted
2(I 1/1, C 0/0, P 0/0, M 3/3)
Rodent dentistry formula
May prevent normal wear on teeth, so they should be clipped or cut
Malocclusions
The mouse’s 2 tail functions
- Balance
2. Thermoregulation
Mice lack these glands throughout their bodies
sweat
The most common type of neoplasia in mice
mammary tumors
How many mammary glands do mice have?
5
These are more prominent in females than males
nipples
Males have open ________ _________ and they must be closed when they are neutered to prevent hernias
inguinal canals
Male mice have this bone
os penis
The predominant WBC in mice
lymphocytes
Mouse urine has
high protein content
The lacrimal gland behind the eyes that produces red tears
Harderian glands
Substance that makes mice tears red
porphyrin
A sign of pain, stress, or illness
chromodacryorrhea
The distance between the anus and genitals that helps determine the sex of mice
Anogenital distance
The anogenital distance is longer in
Males
Female mice’s estrous cycles are
polyestrus
What kind of ovulators are mice?
Spontaneous ovulators
Female mice produce this 12-36 hours after copulation
copulatory plug
Female mice are ready to breed again ____ postpartum
24 hrs
Pups are usually born at
night
Mice cages should be cleaned and food/water should be placed __ _____ prior to partuition
one week
Average litter size
10-12 pups
Baby mice are born _______ and _______
naked, blind
When a group of female mice are exposed to a male (or the scent of a male), the majority will be in estrus by the third night
Whitten Effect
A pregnant female will return to estrus when exposed to a strange male, or the scent of a strange male
Within 48 hrs of copulation
Bruce effect
If a female is bred during postpartum estrus, she will have an extended gestation
Lee Boot effect
Mice do this to recycle B vitamins that are produced by colonic bacteria
coprophagy
Two parts of the mouse stomach
glandular and aglandular
Mice are unable to regurgitate and _______
vomit
Mice have a lot of ______ fat between the shoulders and around the kidney
brown
Rodents have a large ________ within their digestive tract
cecum
Allows food to pass to stomach and does not allow vomiting
Limiting ridge
Supplies 10x the amount of energy than white fat
Brown fat
Energy is stored as _______ in brown fat
glycogen
Most common way to identify mice in a research setting
Notching and punching
This form of identification should have the PI name and contact info, strain, DOB, biohazard info, and # of mice
Cage cards
After a cardiac puncture blood draw, the mouse will have to be
euthanized
These 3 methods of blood sampling can be done when the mouse is awake
- Saphenous
- Lateral tail vein
- Submandibular
These 2 blood sampling methods that need to be done when the animal is sedated
- Retro-orbital
2. Cardiac puncture
Total blood volume calc.
7% x body wt. in g
How much blood can be drawn from a mouse every 2-3 weeks?
Between 10%-15% of total blood volume
Materials needed to do an injection
- 23-25g needles
- tuberculin syringe
- alcohol swabs
To give an IV in the lateral tail vein, it is recommended that you
warm the tail
How much can be given in a IM inj.?
0.05 ml/per site
This route allows for higher volumes of fluid injections
Animal’s head should be tilted lower than the rest of the body to move abdominal organs
IP
Can receive 2-3 ml of fluid with this route
SQ
Max dosing volume for an IP injection
2.0
Max dosing volume for a SQ injection
2.5
Max dosing volume for an IM injection
0.05/site
Max dosing volume for IV injection
0.125
Max dosing volume for PO
1.0
The two common analgesics used in mice
Butorphanol and Buponorphine
Self mutilation is often a sign of
pain
Respiratory dz with morbidity close to 100%
May see with pneumonia as well
May be seen in young weanlings or in stressed mice
Rough hair coat, hunched posture, dyspnea, and chattering are some C/S
Sendai virus
Most common respiratory dz in mice and rats
Bacteria can cause chronic respiratory dz
Rhinitis, head tilting is seen as C/S
Treated with antibiotics in water
Mycoplasma pulmonis
Pasteurella pneumotropica
Caused by the corona virus
Common in immunosuppressed mice
Dehydration, Wt. loss, diarrhea and sudden death are C/S
NEED TO CONTROL WITHIN A COLONY because it is highly contagious and high mortality rates
MHV (mouse hepatitis virus)
Caused by corona virus that causes the swelling of lymph nodes and harderian glands
Animal may have ocular lesions and become photophobic
Sialodacryodentitis
Common in wild mice that is passed by arthropods
Zoonotic
C/S: hunched posture, photophobia, convulsions
Can cause meningitis and flu like symptoms in humans
Transmitted through bites, urine, and infectious tissue
Lymphocytic Choriomeningitis (LCM)
Caused by rotavirus
Common in mice less than 2 weeks of age
C/S: soft, yellow feces
Epizootic diarrhea of infant mice (EDIM)
Caused by Clostridium or bacillus piliformis bacterium—with clostridium being more common
Causes wt. loss. rough hair coat, listlessness, and sudden death
Due to poor housing
High morbidity and mortality
Tyzzer’s Dz
Mouse parvo
Two main types: MPV type 1 and Mouse Minute Virus (MMV)
Targets intestinal and lymphoid tissue—usually subclinical
Causes immune dysfunction
Mouse Parvoviruses
2 common endo/ectoparasites
- Pinworms
2. Mites
Cellophane tape test is used to diagnose this
Pinworms
Common antihelminitic used for treatment of pinworms and mites
Ivermectin
2 mite species that infect mice
- Myobia musculi
2. Myocoptes musculinus
Caused by having wet skin for too long
Moist dermatitis
A mouse’s diet classifies it as a
omnivore
Preferred diet for mice
pelleted
Most common euthanasia method in research
Overdose of CO2
CO2 overdose sometimes will not be successful in mice under
16 wks of age
Injectable drug used with euthanasia in vet offices
Barbituate
