The scientific name of the most common species of laboratory rat is ___.
Rattus norvegicus
In rats, secretions from the harderian gland are commonly referred to as ___.
Red tears
What physiologic feature makes the rat useful as a model for toxicology studies?
Inability to vomit
Animals that are produced as a result of random matings are referred to as ___.
Outbred or stock
When 20 or more generations of brother-sister or parent-offspring mating has occured, the offspring are referred to as ___.
Inbred or strains
An animal with a hole punched at the middle of the left ear and a notch at the bottom of the right earis designated with the number ___.
26
An appropriately sized needle to use for collection of blood from the lateral tail vein of a rat is ___.
22 gauge
The most common repiratory disease of rats is ___.
Murine Respiratory Mycoplasma
Tyzzer's disease is caused by ___.
Bacillus pilliformis
A parasite of rats that has significant zoonotic potential is ___.
Hymenolepis nana.
What order is rats in?
Rodentia
What is the subfamily?
Muridae
What are the two common species?
Rattus rattus and Rattus norvegicus
Rattus rattus is usually the color ___ while Rattus norvegicus is usually the color ___.
Black, Brown
The tail makes up __% of the rats body.
85
What are the functions of the tail?
Organ of balance, and mechanism for heat loss.
Where are the sweat glands found?
The hairless foot pads
Forelimbs have __ digits and the hind limbs have __ digits.
4, 5
In rats bone ephiphyses (growth plates) never __.
Close
What is the Harderian Gland?
Lacrimal or tear gland found in all rats
The Harderian Gland secretes ___.
Porphyrin
Stressed or sick rats will have increased chromodacryorrhea or ___.
bloody tears
What kind of teeth do rats have?
Hyposdontic
True or False:
Rats can close their nares when they swim underwater.
True
What is the large brown fat deposit located diffusely around the neck and between the scapulae?
Hibernation Tissue
What is the HIbernation Tissue used for?
Provides energy storage
What are some studies that we can test on rats?
Hypertension, diabetes, cataracts, obesity, behavioral, and dental studies
What studies are rats NOT good for?
Cardiovascular and Gastrointestinal studies
Cardiovascular studies are not good because?
Paired vena cava make their cardiovascular system more similar to a fish than to a human
Gastrointestinal studies are not good because?
Monogastric stomach but is divided into a glandular portion and nonglandular portion seperated by a limiting ridge. They also do not have a gallbladder.
Rats are continuously in ___.
Polyestrous
Their estus cycle last ___ days.
4-5
Rats will go back into estrous within ___ hours of parturition.
24
Babies are called?
Pups
Gestation last __ days.
22
Pups are born hairless, blind, and deaf. Ears open by __ days, eyes open __ to __ weeks, and start eating solid foods by the end of __ weeks.
5.
1-2.
2.
Males have a __ distance between the papilla and the anus.
Greater
When dried semen mixes with secretions from the vagina is called?
Copulatory Plug
What is monogamous mating?
One female is bred to a single male, meaning only two rats in one cage.
What is polygamous mating?
Two or more females are bred to a single male, this means allowing more the two rats per cage.
What is INTENSIVE breeding systems?
Continuous housing of male and females. Allows you to take advantage of the postpartum estrus. Risk fighting between the rats. Maximizes the number of total possible offspring.
What is NONINTENSIVE breeding?
Less stressful on the females as the males are housed away from the females. Breeding doesn't occur until after the current litter is weaned. Fewer total offspring in a colony. Minimizes injury to offspring and fighting between adults.
What is STOCK? What is another term for this?
A type of rat bred randomly. These are NOT inbred! Also called, OUTBRED. They have similar characteristics, but are not genetically identical.
What is STRAIN? What is another term for this?
A type of rat that has been inbred. Inbred is the other term. At least 20 generations of brother-sister or partent-offspring mating has occured. Genetically homozygous or identical. Should all respond to medical treatment exactly the same way. Inbreeding also concentrates undesirable traits.
What strains are used for mammary tumors?
Albany Strain
What are Brown Strains used for?
Myeloid leukemia
What strains do we use for autoimmune disease?
Buffalo Strains
BEHAVIOR:
Normally nocturnal, but can adapt.
Highly socialable.
Females housed together are more likely to fight then males.
Females with litters are more likely to behave aggressively.
Like to burrow, explore, and climb.
Colorblind.
Must chew to keep incisors from overgrowing.
HUSBANDRY, HOUSING, and NUTRITION:
Shoebox cages, solid bottom wire lid.
Bedding should be soft, absorbent, dust free, and nontoxic.
Cedar is NOT used because it can affect the liver, and respiratory system.
Environmental enrichment includes things to climb on, extra bedding, tissues, and boxes to hide in.
TEMPERATURE and HUMIDITY:
__ - 75 Degrees
40- __ % Humidity
Low humidity predisposes an animal to ___.
65.
60.
Ringtail (tail necrosis): A lesion or annular constriction of the tail resulting from the lack of hydration in the skin of the tail.
MORE ENVIRONMENTAL INFO:
Excessive noise can cause:
- ______
- ______
Rats are generally fed __ ____, but some may overeat.
- They need to eat their food in several meals throughout the day and usually eat 5 grams of food per 100 grams of body weight.
- Pregnancy and nursing increases this up to four times.
- A drop in reproduction
- Increase in cannibalism
Ad Libitum.
What does COPROPHAGIA mean. What should rats eat?
Eat their own feces. Commercial rat chow and additional food, vegetables, and seeds.
What are some techniques to indentify rats?
Ear punching, toe clipping, tattooing (tail, ears, toes).
What are some injection techniques?
IV, SC, IP, and IM.
What places do we draw from with IV?
Saphenous, jugular, femoral, or lateral tail veins. Most preffered is lateral tail vein because the small volumes.
Where do we give an SC injection?
Nape of neck.
Why are IM injections not common?
Small muscles, easy to damage nerves. They will self multilate if there is muscle damage.
What injection do we give directly into the lower left quadrant of the abdomen?
IP injections
How do we monitor anesthetic depth?
Toe pinch, and respiratory rates, and maintain body temperature.
What is a normal temperature, respiratory rate, and heart rate? While under anesthesia, what brpm should we not let the respiratory rate fall under?
Temp: 99.8 * F
RR: 71-146 brpm
HR: 313-493 bpm
DANGER under 60 brpm
What are the types of inhalation anesthetics do we use on rats?
Isoflurane and Halothane
What are some methods of collecting blood samples?
Tail clip, toenail clip, venous collection.
What is the best vein to collect from in the venous collection?
