Exotics Test #2

Units #3-4 (pg 40-51)

MICE QUESTIONS

what are the three housing options for mice?

1. shoebox caging

2. metabolic caging

3. micro isolation caging

true of false? Housing female mice in pairs or groups is allowed but male mice not of the same litter need to be housed separately to avoid fighting and lower stress

• true

fill in the blanks 

______________ is a dominance behaviour where the dominant mouse pulls the hair from the other mice in the cage. ___________ of these animals should occur to avoid this progressing into fighting.

• barbering 

• separation

note: to determine which one gets removed from the group look for the one that looks the most intact (has most of the hair & is likely the bitch bully)

what type of cage is used to accurately monitor food consumption and waste production of an animal?

• metabolic cages

what type of cage prevents pathogens from entering or exiting the cage in a barrier facility? 

• micro Isolation cages

true or false? To get a hold of a mouse, grip the tail at the tip and lift it out of the cage

• false, grip the tail about midway down its length and lift it out of the cage

fill in the blanks

enough ________ __________ must be gripped otherwise the mouse can twist its head and __________. Therefore if you fail to take enough at the first attempt then ____________________________________.

• loose skin

• bite

• put the mouse back and start again

note: trick is always to let the mouse grip into something such as a metal cage, sleeve, etc as it’ll allow you to adjust and get a good grip. 

fill in the blanks 

mice are sexed by comparing the ___-__________ _____________. 

This is always _________ in males than females.

• ano-genital distance 

• greater

note: to remember which sex has the longer distance remember you need room for the testicles therefore male mice have the longer ago-genital distance.  

true of false? it is easier to tell the sex of mice when they are 2 weeks old rather than newborns.

False, it is easier to tell the sex of a newborn mouse than one that is 2+ weeks old because they haven’t developed yet making it easier to measure the ano-genital distance

what is the most convenient site for SQ injection in mice and how do you perform this injection?

• lumbar area 

• insert needle under skin (caudal to cranial) slightly lateral to the spine so you don't hit it

note: SQ can be given anywhere but near the tail is the best

DON’T BE A ____________ (Tallon’s inside joke)

• Melissa

note: don’t so a SQ injection directly overtop of the spine and almost wipe out an entire species

fill in the blank

up to ____ ml(s) may be injected SQ in mice.

• 1ml

when giving a IP injection in mice why is the head lower than the hind legs?

• so that the abdominal organs fall away from the injection site

fill in the blanks

when giving an IP injection to mice insert the needle just off the __________, halfway between the ________________ and the __________________________. Aim toward the ___________ of the abdomen, use a quick poke to pass the _________, and advance only __ mm.

• midline

• caudal end of the sternum

• cranial aspect of the pelvis

• center

• muscle

• 2–3

fill in the blanks

when doing IV injections in mice the tail may be warmed with a __________, but _____ breeds are sensitive to __________ so be cautious. always inject in the __________ vein, not __________ arteries.

• heat lamp 

• Albino

• light 

• lateral (parallel)

dorsal/ventral 

note: you warm the tail to dilate (open) the veins and improve blood flow, making IV access easier and safer as well as allowing you to find and enter the vein correctly

true or false? the correct site for IV injections in mice is the dorsal tail artery

• false, IV injections in ice are given in the lateral tail vein.

multiple choice

which of the following indicates an injection has missed the vein?
a) rapid blood return
b) no resistance to injection
c) white swelling around site
d) tail turns pink

• C white swelling around the site 

true or false? subsequent (additional) injections should move caudally after the first injection

• false, always start low on the vein and work up so that if the first attempt is a fail you can still try again

true or false? An oral gavage (stomach tube) is sharp for easier insertion and a cough reflex means you are in the esophagus

false, An oral gavage (stomach tube) is blunt and a cough reflex means your in the trachea which is BAD

what is the length and diameter of rodent gavages and what type of tip do they have?

• 10cm long 

• 1-2mm diameter

• blunt tip

note: the gavage will be inserted STRAIGHT from the nose to the xiphoid process (don’t go past) right where the stomach is located.

what is the maximum fluid volume that can be given to a mouse by gavage? approx how long should a mouse be fasted before gavage to allow for a slightly larger volume of fluids?

• 1ml

• 12hr

why would you gavage a mice?

• if they are not eating

• giving medication 

• accurate dosage for testing 

in mice what vein is used for blood collection?

• saphenous vein

what are the 3 steps involved when collecting blood in mice?

1. restrain mouse (use 2cm diameter tub or commercial restraining device)

2. shave area & poke needle in vein (lengthwise to avoid severing the vessel)

3. collect blood in hematocrit tube (used for PCVs, smears, etc)

note: if you are taking blood again that day there no need to poke them again, just take a cotton pad and remove the scab then collect the blood.

when performing a IC puncture on a mouse how much blood can be collected. what is this procedure considered? Large or small needle?

• 1-2ml

• terminal procedure (anesthesia is mandatory)

• larger needle to avoid destroying fibrinogen so that blood can clot for serum analysis

true or false? the longer a mouses heart is pumping the larger amount of blood you’ll get.

• true, once IC puncture occurs massage chest to increase venous return so you get the most blood

what is the blood collection method in mice that can be done no more than once per week, up to twice per eye, with a maximum withdrawal of 1% of the animal’s body weight?

• retro-orbital blood sampling 

note: this is done because it gives you a larger vol of blood compared to saphenous vein.

true or false? in retro-orbital blood sampling anesthesia is mandatory and this practice may be a terminal procedure but unlike IC puncture recovery is possible.

• true

what are the steps of a retro-orbital blood sample collection? 

1. anesthesia 

2. micro-hematocrit capillary tube placed at medial canthus of eye under nictitating membrane  

3. gently thrust tube past the eye 

4. retro orbital sinus will get punctured 

5. blood is collected

note: eye should remain uninjured and topical anesthesia is administered to reduce post procedural pain. 

RAT QUESTIONS

true or false? rats are housed in the same manner of mice but in larger cages with females in groups of 2-4 and mature males housed alone.

• true, they have bigger cages, f are in groups of 2-4 and mature males are housed alone.  

true or false? unlike in mice female rats have the greater ano-genital distance than male rats. 

• false, sex identification for rats is the same as mice

what is the difference between rats and mice when it comes to behaviour?

• rats are more friendly and cooperative than mice as they only bite when over stressed and genuinely are friendly curious animals. 

What two things can help when it comes to handling rats?

• socialization and positive conditioning can greatly help in handling rats

fill in the blanks

stress in rats can be detected by the presence of __________ “red tears” secreted around the nostrils and eye by the _______ gland this is known as _____________________

• porphyrin

• harderian

• chromodacryorrhea

note: porphyrin starts off as red dots appearing on the nose and progress into the red fluid coming out of the eye and or nose

What does dried porphryin look like and when does it happen?

Dried porphyrin which has been groomed away from the rats face has a similar appearance to flea dirt and happens under chronic, physical or environmental stress

what are ways you can confirm the gavage tube is in the right place? 

1. palpation of throat

2. inject small amount to see if there is a cough response

when removing a gavage tube what should you ALWAYS do? what should you apply to it before insertion?

• pinch it so they don’t aspirate any fluid that may drip out of tube when being pulled out

• apply lube

RABBIT QUESTIONS

how are rabbits normally housed?

• rabbits are housed individually shortly after weaning as fighting is common in both sexes even among litter mates.

• they are grouped housed in large enclosures to assess their natural behaviours (encouraged whenever possible in compatible animals not just rabbits)

fill in the blank

rabbits are generally quiet and docile but they frighten easily because they are ___________ animals.

• prey animals

how do you pick up/restrain a rabbit?

1. approach slowly

2. scruff neck and draw rabbit back towards you

NEVER LIFT FROM EARS

3. slide hand under belly and lift up

4. place thumb around each leg above the hock

5. tuck head under your arm (calms them)

fill in the blank

when returning a rabbit to its cage it must go in _____________

• backwards to it doesn’t leap forward potentially injuring itself or the handler

note: easily attain spinal damage if not handled correctly

how do you tell the sex of a rabbit?

• apply pressure in front of the genital opening. if male the penis is extruded but if female only a vulval sits visible

true or false?

• testes are usually retracted in the male rabbit even when mature

• true

how can you verify a stomach tube is in the right spot for a rabbit?

• throat palpation

• feeling no air exiting the tube on exhalation

how do you place a stomach tube in a rabbit?

1. estimate the length of the stomach tube before insertion 

2. apply lube to the 2-4mm in diameter red rubber catheter (used as a stomach tube in rabbits) 

3. place 1.5cm diameter gag in the mouth behind the incisor teeth

note: a gag is used to prevent rabbit from biting stomach tube

4. insert red rubber catheter with gentle pressure until rabbits swallow reflex naturally kicks in 

5. attach syringe to the tube and give solution slowly

what vessel is used in rabbits to collect blood?

• lateral ear vessel

note: shave or pluck the site and then cut the vein longitudinally for about 1mm using blood lancet or small scalpel blade.

what is used to collect blood in rabbits?

• capillary tube (drop)

• needle & syringe (small volumes)

true or false? blood samples larger than 5mls may be collected using a needle and syringe in the central artery of the rabbits ear

• false, blood samples >5mls may be collected using a vacutainer from the central artery of the rabbits ear.

note: insert needle with the bevel TO THE SIDE this prevents the arterial wall from occluding the opening to the needle 

what do you know about rabbit SQ, IP and IV injections?

SQ: technique is same as cats and dogs

IP: advance needle no further than 1 cm into abdomen

IV: given in ear vein 

true or false? after an IV injection in the ear vein either the restrainer applies pressure to the site or a paper clip can be used if done alone.

• true, but don’t forget to remove the paperclip (placed halfway across the vein) after 1-2 minutes or it can stop circulation and cause damage

how do you collect blood from a rabbits ear vessels?

1. shave or pluck site

2. cut vein longitudinally for about 1mm using blood lancet or small scalpel blade)

3. collect blood 

• drop → capillary tube

• small volumes → needle & syringe 

• >5mls → vacutainer (use central ear artery)

note: insert needle with bevel to the side to prevent the arterial wall from occluding the open needle

LABRATORY ANIMAL BREEDS

how are animal models selected for human medical research?

• based on the similarity in physiology and anatomy to a human 

example: pigs are omnivorous and have similar GI function to humans, therefore are commonly used for gastroenterology research.

what are the two legal ways to source research animals?

1. purpose bred animals

2. random source animals

fill in the blanks

_________________________ are born and raised under controlled contains and may be genetically manipulation. this is becoming more common as researchers demand animals with particular genetic makeups. 

• purpose bred animals 

fill in the blanks

___________ ___________ laboratories and ___________ laboratories are the largest source of purpose bred research animals in Canada and the US.

• charles river

• jackson

fill in the blanks

animals that are purchased from shelters, farms or breeders are considered  _______________

• random source animals 

why are random sourced animals preferred to purpose bred animals in some cases?

• cheaper since no genetic modifications or SPF were done plus not all species are available from reach breeding facility like sheep. 

true or false? random sourced animals do not have to be legitimately/legally acquired as outlined in the AUP

• false they do have to be purchased legally and legitimately as outlined in the AUP

what 4 things must be considered when selecting the appropriate breed of laboratory animals?

1. litter size

2. life span

3. ease of handling

4. genetic modification availability