Laboratory Rat Flashcards
What are the two most common species of rats?
Rattus norvegicus
Rattus rattus
What is the common name of Rattus norvegicus
Brown or Norway rat
What is the common name of Rattus rattus
Back, house, roof or ship rat
Which rat was responsible for the spread of the “Black Death”
Rattus rattus
What is the average life span of rats?
26-40 months
What is the age of puberty of rats?
6-8 weeks
What is the estrus cycle of rats?
4-5 days
What is the length of gestation of rats?
21-23 days
What is the average litter size of rats?
6-13 pups
What is the weaning age of rats?
21 days
Do rats have sweat glands?
No except for those on the hairless foot pads
How many digits do rats have on their forelimbs?
4
How many digits do rats have on their hindlimbs?
5
What is the type of lacrimal gland called?
Harderian gland
Where is the harderian gland located?
It occupies much of the orbit of the eye
What is the discharge of the harderian gland confused with?
Blood. This is a normal secretion of the gland
What is the condition called when the secretions of the harderian gland increase when the rats are under stress?
Chromodacryorrhea
How many pairs salivary glands do rats have?
3
what is the condition called when the teeth grow continuously throughout life?
Hypsodontic
What is the brown fat of rats called?
Hibernation tissue
Why do rats make a poor model for heart studies?
Their cardiac tissue is more closely related to fish
Do rats have a gall bladder ?
No
Why are rats used in dental research?
Because their molars closely resemble humans
Why are rats used in toxicology studies?
Due to the inability to vomit
What are purpose-bred rats?
They are susceptible to specific human diseases
Why are rats good models for behavioral studies?
Due to their unique ability to adapt to new environments
Wistar strain
Albino, outbred
Sprague-Dawley (CRL:SD)
Albino, outbred
Long Evans
Hooded, black & white, inbred
Gunn Strain
Hooded, inbred
Fischer344 Strain
Albino, inbred
Lewis Strain
Albino, inbred
Buffalo Strain
Albino inbred
ACI Strain
Brown inbred
How do you determine gender?
Males have a larger genital papilla than females and a greater distance between the papilla and anus
What do rats look when they are born?
Hairless
Blind
Deaf
Monogamous Mating System
One female is bred to a single male
Polygamous Mating System
Two or more females are bred to a single male
Intensive Breeding method
Continuous housing of male and female animals
What are the disadvantages to the intensive breeding system?
Effectively takes advantage of the postpartum estrus
Higher incidence of fighting between adults
Greater likelihood of injury to offspring
Higher stress to females because they are nearly always pregnant or nursing
Nonintensive breeding method
Separate housing for the male and female while the female is pregnant
What are rats bred specifically for?
Their susceptibility to specific diseases
Stock
Refers to a type of rat that has been randomly bred
Stock =
Out-bred
Out-bred stocks
Have similar characteristics but are not genetically identical
Strain
Refers to the type of rate that has been inbred
When is a strain considered inbred?
When at least 20 generations of brother-sister or parent-offspring mate
In-bred strains
Concentrates undesirable traits as well as desirable ones
What decreases with inbreeding
Genetic variability
What increases genetic variability?
Outbreeding
What is a group of rats called?
Mischief
What helps keep the incisors from overgrowing?
Continuous chewing
What cages are rats usually housed in?
Solid-bottomed shoebox cages with wire lids
What kind of bedding should be used?
Soft
Absorbent
Dust free
Nontoxic
What kind of bedding should not be used?
Soft woods such as cedar because they contain compounds that affect hepatic enzymes and can cause respiratory problems
What temperature is the ideal temperature to keep rats in?
65 to 75 degrees F
What is the best humidity to keep rats in?
40% to 60%
What does low humidity predispose rats to?
Ringtail
What causes rats to have audiogenic seziures?
Loud noises
How much water should a rat consume?
13 to 20 mls per 100 grams of body weight per day
How much food should a rat consume?
5g per 100g of body weight perday
What are rats?
Coprophagic
What is the shelf life of most commercial rat chows?
6 months
What other food items may pet rats be given?
Fruits
Vegetables
Seeds
What are 4 types of identification
Microchip
Ear Tag
Ear punch
Tattoo
What is the maximum volume to be injected into a rat SQ?
0.2ml/10g
What is the maximum volume to be injected into a rat IP?
0.2ml/10g
What is the maximum volume to be injected into a rat IM
0.1-0.3mL/ site
What is the maximum volume to be injected into a rat IV?
0.05mL/10g
What is the maximum volume to be injected into a rat IO?
0.1ml/site
Where can you give a rat SQ injections?
Nape of neck
Loose skin over abdome
Where do you give a rat IP injections?
Lower left quadrant
Head positioned downward
Is IM injections recommended?
No because of the small muscle mass
What methods are appropriate for evaluating the degree of anesthesia in a rat?
Toe pinch
Respiratory rate
What are common Anesthetic and Tranquilizing Agents used in rats?
Isoflurane (inhalation) Acepromazine (IP) Diazepam (IP) Ketamine/Acepromazine (IP) Ketamine/Xylazine (IP) Propofol (IV)
What determines the method of blood collection that will be used on a rat?
Volume of blood needed
Age of the animal
Skill level
What is the total blood volume of a rat?
50ml/kg
What percentage of blood should not be withdrawn at one time from a rat?
No more than 10%
What vein can be used to collect a larger volume of blood?
Tail vein
What other veins may be used but may require anesthesia
Jugular vein Cranial venal cava Lateral saphenous Retrooribital sinus Cardiocentesis
