Ch18 - Mice Flashcards
What is the most common form of enrichment for mice?
Group housing
What is the term used when a mouse (or any animal) chews the hair off its cagemates?
Barbering
In addition to having no hair, what is another characteristic of nude mice?
They have a deficiency in their immune system.
If a mouse’s dorsal pelvic bones are readily palpable, and the segmentation of its vertebral column is evident, it would be considered _______________, with a body condition score of _____.
Under-conditioned; BCS = 2
What stocking density (number of animals per cage) for mice is indicated by the Guide?
4-5
How long is the gestation period in non-lactating female mice?
19-21 days
How long after mating can mucous plugs remain in the rodent’s vagina?
24 hours
What is the average weight of a newborn mouse?
1 - 1.5 grams
How often do female mice go into estrus?
Every 4-5 days
What is “tunnel handling”?
Letting a mouse enter an enclosed tube and moving the tube between cages
What is one advantage to feeding mice pelleted feed?
Mice gnaw the pellets, which helps to wear down their incisors (preventing malocculsion)
What is the scientific name for the common laboratory mouse?
Mus musculus
true or false: Removing the dominant mouse will stop mice from fighting their cage mates
False
When is toe clipping usually done?
With neonates, with IACUC approval (not a recommended ID method)
What does the designation “F1” mean for a hybrid strain?
It’s the first generation of the mating scheme
What are three factors that influence the level of aggression shown by mice?
Territoriality, social dominance, and strain
True or False: outbred mice are created by mating a closed population (animals at least 4 generations) of unrelated animals.
True
True or False: Mice less than 10 days old may be cause by cupping the hands around the whole body or by picking up a group of pups together with a small amount of nesting material
True
True or False: Both respiration and heart rate in the mouse are easily measured by observing or feeling the chest
False (heart rate and resp. rate are too fast to observe visually)
True or False: An acceptable management technique that may reduce or prevent fighting among male mice housed together is to house young males together from weaning.
True
True or False: Inbred strains usually have larger litters than outbred stocks
False (smaller litters)
True or False: By 7 days of age, mouse pups are fully furred and their eyes are open
False (occurs ~10-14 days)
What are hybrid mice?
The offspring of two different strains of mice
True or False: Female mice exposed to constant light may stop having an estrous cycle
True
List 5 signs of pain, distress or illness in mice.
- ruffled fur
- dehydration
- hunched posture
- inactive
- weight loss
Skin tenting and sunken eyes are signs of what health problem?
Dehydration
Newborn mice are ___________, meaning that they are born hairless and helpless, with eyes and ear canals closed
Altricial
What is the term for coming into heat 24 hours after giving birth? (time period varies between species)
postpartum estrus
How much does an adult male mouse weigh?
20-40 grams
How much does an adult female mouse weigh?
18-35 grams
What is the average life span of a mouse?
12 - 36 months
Female mice come into heat within ___ hours of parturition
14 - 28 hours
How many pups are generally in a mouse litter?
4 - 12 mice
At what age (days) are mice pups weaned?
21-28 days
Disturbing litters after birth can lead to ________.
Cannibalism
Failure to wean litters on time can lead to ________.
Overcrowding
Females reach puberty/estrus around ______ weeks, but they typically don’t start breeding until ____ days.
4 - 5 weeks; 50 days
Low humidity in an animal room can cause what disease in mice?
Ringtail
