----start----

Review Session:

review of the things to carry away and 
not forget; very closely reflecting the exam. not giving us answers but 
giving us the concepts we need to know.

Covering things that should be 
common sense...what should you know as a vet going into practice about 
lab animal med, animal welfare, your legal, moral and ethical obligations 
to animals in society, etc.

There's only one law covering lab animals: 
the Animal Welfare Act. it says all animals, all vertebrates, are 
covered. But the USDA enforces the law. The USDA says that "animal" is 
defined under their regulations as a vertebrate that isn't mus musculus 
or rattus norvegicus (common lab rat and common lab mouse), 
or isnt a 
bird or isn't a farm animal on agricultural study.

people will ask you 
why is this? it's probably because 90%+ of the animals used in research 
are rats and mice and the USDA thought they wouldn't have enough manpower 
to enforce the law but could cut the workload a lot by eliminating rats, 
mice. most of these animals are used for toxicology testing at 
universities where you have to abide by GLP, FDA regulations, etc.

FDA: 
federal body that has jurisdiction, protects us, the people, ensures that 
drugs are healthful, safe, and can be taken without worry. their 
regulations end up covering the rats and mice (under the GLPs)

to get 
Federal money, you have to follow PHS guidelines. these are not law, just 
guidelines. if you break them, you just don't get the money you do not go 
to jail. many rats/mice get used at institutions that need federal money. 
so again, USDA probably figured rats and mice didn't need to be covered 
by AWA. AWA also doesn't cover farm animals used in agriculture research. 
a cow on surgical study in human research lab is covered. but a cow on a 
study to increase milk production isn't covered by AWA.

USDA says if you 
use research animals you must be a licensed, registered place - includes 
zoos, circuses, all places using animals. this is law. can go to jail if 
you don't follow.


PHS oversees all use of animals at places applying 
for Federal money. this applies to the whole institution if any part of 
the institution wants to get a federal grant. have to register with USDA 
(OPRR) and follow PHS guidelines. if you don't, your money is withheld. 


USDA has inspectors come to facilities no less than once a year, 
sometimes more. at research facilities the inspectors are all 
veterinarians. you also file an annual report with USDA spelling out # of 
animals and what they were used for (four categories of use - not 
suffering pain or distress, suffering pain or distress while medicated, 
suffering pain or distress without meds but justifiably, or whatever). 


with PHS, every institution has to file "animal assurance" describing all 
the stuff you do with the animals. follows the Guide for the Care and Use 
of Lab Animals. no law requires you to abide by the Guide, but the laws 
refer to the Guide so it's the document to use. 

as a vet, what is your 
obligation? every institution registered with the USDA or which has an 
acceptable PHS assurance must have an IACUC made of a specified number of 
people, to oversee animal use and protect animals. PHS says must be not 
under 5 people. USDA says not less than 3 people. both say one of the 
people must be a veterinarian. PHS says the veterinarian must be 
experienced, and have appropriate training and background in lab animal 
medicine. 

close to 50% of this class will be a formal IACUC 
veterinarian at some point. if you do this you sign papers which say to 
USDA, PHS, etc that you are overseeing stuff, and that you are satisfied 
that the place has an acceptable animal care and use program. this is a 
huge legal and ethical responsibility. dont just sign things blindly, 
make sure everything is being done appropriately first.

where to go for 
help: 

-local lab animal vet such as Dr Francine Mallon here at ULAR

-ACLAM: board certification organization for lab animal medicine vets

-nearby research institutions also have vets on staff who can help
-vet 
schools
but have someone you can call to get help. know your 
responsibility and authority. vet has authority to terminate any research 
project if animal isn't being treated properly. you can euthanize an 
animal on study if you feel it is appropriate. if it is being operated on 
without anesthesia or something, you can euthanize it. you have this 
authority. you'll have to answer for it later but this is your legal 
right and moral obligation. don't look the other way 
if animals are 
being used inappropriately

ASLAP: made of practicing lab animal vets, 
not board certified necessarily. it's only $20 to join, you get 
newsletters and stuff so if you are a consulting lab animal vet join!


AALAS: all people interested in or working in lab animal science. made of 
vets, PIs, techs, caretakers, industry people, etc. a good resource. they 
have a journal which is a useful reference for the lab animal vet. 


ILAR: institute for lab animal resources - part of NAS in DC. has a lot 
of publications that are useful - guidelines for various things. 

most 
of these places have websites, you can get info that way. 

Every state 
has an animal cruelty law. know that law for your state and keep it on 
your desk. people - local cops - will ask you about it. once police came 
and asked about a dog being kept in a run in the hot sun with no water. 
Dr R needed to know if this was *legal* or not. 

PHS and USDA protect 
welfare of animals.
also know: AALAC - a voluntary accrediting agency 
available to any institution that uses animals. seal of good 
housekeeping. any institution can apply for accreditation, and if you get 
it, then you are abiding by practices well above the minimum standard of 
care. no agency requires AALAC certification. but 95% of animals used by 
research fall under the AALAC umbrella - large facilities are usually 
participating in this program.

comply with the law (USDA)
get PHS 
insurance
USDA comes and inspects
PHS does stuff by reading your 
assurance statements
AALAC accreditation is another assurance

it's 
required by all three of those accrediting and assuring agencies that 
institutions have IACUCs - that committee has responsibility and 
authority to oversee the animal use program, and reports to the local 
institution official (provost) and the PHS and USDA - directly to them. 
if the institution isn't complying with their assurance statement, the 
committee has to report it to the PHS, for example - not just to the 
provost, etc. this is what really happens.  

that is about it for 
regulations and guidelines
--

mice and rats make up about 90% of animals 
in research.
# of mice and rats are not counted by anyone. USDA doesn't 
cover them so the # isn't reported. some people think the #of animals 
being used is going down/ others think it is going up. however it seems 
to Dr R that they are increasing with transgenic mouse work.

# of 
aniamls as defined by USDA has been decreasing steadily for 10 years. 

quality of work has been going up - quality meaning animals not suffering 
disease or distress or being used inappropriately, so data is more 
valuable and more useful. records show the data and science being gained 
is increasing as # of animals decreases. that idea was started in 1950s 
by russel and birch who wrote a monograph saying we should strive to 
follow the three Rs.

Three Rs: refinement, reduction, replacement

using 
fewer animals = reduction
using more effectively and efficiently = 
refinement
getting data without using animals = replacement --> 
pyrogenicity testing required by FDA - requires you to test all drugs to 
see if they cause fever - previously was mandated that it be done in 
rabbits - but someone figured out they could do the same thing using 
lymph from a horseshoe crab. but you only use 1 crab for each 100 rabbits 
previously used. this is the Limulus lysate test.

in immunology 
research, mAb are produced and usually in mice. this is no fun. you 
inject mouse abdomen with an irritant, then inject antigen, and mouse 
will make monoclonal Ab. there are test tube methods being tested to 
replace this. we're going to be able to do this in test tubes soon, we 
think. this is going to really reduce the number of mice used. 

Norm 
Peterson talked about things like this. 
understand the three Rs are with 
us, being encouraged, what they mean. 

alot of mice are used in 
research, because they are cheap (by law, it's not permissible to use 
cost alone as the reason to choose an animal), because they work, have 
been inbred for many generations - inbred strain has been inbred 20+ 
generations which reduces genetic variation. you make every trait nearly 
homozygous. you end up with almost clones. individuals are almost 
identical. far fewer variants. 

inbred x inbred = hybrid

when you breed 
inbred animals, many recessive traits which are undesirable come to the 
surface. the animals are less efficient reproducers. but for the vast 
number sof toxicology tests, they want animals with hybrid vigor - 
healthy, robust, thriving, easy to maintain, living long - but identical. 
so cross two homozygotes - you get identical offspring each time. so if 
you cross inbred1 x inbred2 you get a hybrid - identical offspring, with 
hybrid vigor. 
these animals are thrifty, healthy, do great - used for 
toxicology tests, mainly.

Bedding - animals such as rats and mice are 
kept in cages with bedding. some cages have wire bottoms which aren't 
good b/c the animals get sore feet, cut the feet, get irritations. 
rats/mice on chronic studies invariably get sore feet if housed on wire. 
it's been suggested and FDA is considering outlawing wire cages for 
chronic studies in rodents. chronic = more than 6 mos, over a year. 
lesions are seen somewhere around a year of age. 

mice have and rats 
have open rooted incisors, that grow forever. gnawing animals. when they 
gnaw, they wear the tooth surfaces down. teeth grow forever. when fed 
commercial food, sometimes teeth grow too long and they need trimming. 
clip or file them. if you see animals in practice you may have to do 
this.

rabbits have incisors that continue to grow
guinea pigs have 
incisors and molars that continue to grow - float them with a tiny file 
like you would a horse.

rats have no gall bladder - this is going to be 
on your state boards :)
are you aware of the Mosby book - preparation for 
state and national boards? there are a lot of lab animal questions in 
there by dr r. :)

if you use a solid bottom cage, you need bedding - 
change it usually about once a week. be careful of soft-wood beddings 
that give off resins, aromatic hydrocarbons that affect microsomal enzyme 
function. use care with anesthetics - may be increased sleeping time 
especially with barbiturates. it's ok to use pine or cedar as long as it 
isn't a research animal. but know there will be problems with 
barbiturates and do not use them on animals kept on aromatic wood 
beddings. 

pet stores also have hardwood chips. 

what should 
temp/humidity be for small rodent? about 70 F +/- 10; the guide says +/-2 
degrees, making a big point that the temperature should not fluctuate 
widely b/c it gets stressed out. so give extra bedding so he can tunnel 
and stuff if gets cold. also, when you heat air it loses moisture, so 
humidity goes down. many heating systems have humidifiers so you can add 
water making humidity b/w 40-60%. if you get below 20% humidity (and 
manyhomes do), rats and sometimes mice will get chronic URI, ringtail 
(natures way of conserving something in the rat, constricting the vessels 
in tail, losing the end of the tail) raise humidity and condition will 
correct. except, you had a talk about gerbils - gerbils like it dry, they 
are desert creatures. if humidity > 40%, that gerbil will look sick - 
will have bad skin, furcoat, but won't really be sick. fix this by 
lowering the humidity. if you have a gerbil and a mouse, hmmm. use common 
sense. put a wet thing in mouse cage - pan of water will increase 
humidity in the cage a lot.

chinchillas are animals which require high 
humidity

common diseases in mice and rats:

red stuff coming out of 
nose/eyes - often looks like blood but really is harderian gland 
secretion - porphyrin pigments - rats respond to stress by having 
porphyrins secreted by harderian glands, then they groom themselves and 
get this all over. it's any nonspecific stress that can induce this.


many organisms cause URI in mice/rats. good colonies shouldn't have them. 
but pet animals will pick stuff up. in a stressed animal with wrong 
humidity, or cat staring at it all the time, you can see the red stuff 
come out.

it's not uncommon for these porphyrin secreting animals to get 
ulcers of the eye probably due to tear duct blockage. reduce stress and 
tx with eye ointments and will go away.

Gerbils have spontaneous 
epileptiform seizures. if you see them, do nothing, they go away 
spontaneously, it's a genetic trait, you can't fix it, it doesn't respond 
to therapy and it doesn't require tx. just explain to the client.


gerbils are monogamous. best to leave male with the female. books say 
they mate for life. they WILL accept a new mate but do not like to. male 
will care for young with female. gerbils get Tyzzer's disease, bacterial 
disease you should know about b/c they are very sensitive and are used as 
sentinels in some mouse/rat colonies b/c mice/rats do not show clinical 
signs but can get infected. 

most bacterial infections in small rodents 
are tx w/broad spectrum abx in water - chloramphenicol, sulfas, common 
sense. something you have that will dissolve. 

it's not very rewarding 
to inject a mouse or rat with abx, it's much more easy and successful to 
put stuff in water.

albinos - most research rats/mice have no pigment, 
their retinas are susceptible to light. the light in this room is about 
85 foot-candles. if you subject albino rat to 100 foot candles, will go 
blind in 3-4 weeks. need subdued light. can do fine if blind, and you may 
not notice if pet goes blind, but it's not a good idea. in a lab, keep 
light at 30-40 foot candles. typical living room is probalby no more than 
40 foot candles. plenty of light.

gerbils - tail-slip. don't pick 
gerbils up by the end of the tail. pick up by the body or the very base 
of the tail. this CAN happen in rats and mice too, but less often. rats 
may twirl when you pick up and twist off the skin. pick up by the bodies. 


gerbils are nice, curious animals. even ones that aren't handled much 
will come up to you and check you out and don't usually bite very much or 
run away.

hamsters are not nice. they are cute but evil. not good pets 
for kids. be careful. they will bite you first and think about it later. 
they also hibernate at 45-48 F which isn't very cool. clients have 
brought hamsters in that appeared nearly dead b/c they turned the heat 
down while out on vacation. when they got home, hamster was comatose, 
breathing slowly, heart rate slow -- hibernating! they come out of it 
with temperature increase, but it takes some time. if you see hamster 
like this find out where he's been, then put him in 70 F room for a 
while. do not heat up TOO fast. 

hamsters have cheek pouches. this is 
important why? b/c they do not have lymph drainage - they are 
immunologically privileged - will not reject foreign tissue - if you need 
to put in foreign tissue or something this is a good place. in practice, 
can get impacted. can clean out from the inside. 

chinchillas need high 
humidity - 50% is too low. they aren't good housepets, really. they need 
high humidity. most homes don't have that. they need dust baths with 
diatomaceous earth or they get skin problems. if clients have chinchi 
with skin problems, raise humidity to 50% + and give some dust baths.


malocclusion of incisors of rats/mice; molar malocclusion more common in 
g.pigs although incisors can happen too.

guinea pigs need high levels of 
vitamin C - commercial foods don't have enough unless very fresh. 
supplement their food. you can put it in water or use green leafy 
veggies, etc. 

no animal likes fluctuations in temp, but g.pigs in 
particular get respiratory problems from temperature fluctuations. they 
can tolerate a wide range but need it to be stable. g.pigs are precocious 
- born with eyes open, running at full speed and eating solid food at 5 
minutes of age. can do fine without mom. do better if they nurse for a 
few weeks to get started but if mom dies, young should be ok on solid 
food - though you may have to teach them to eat. 

female guinea pigs 
have a pelvic ligament that relaxes from 1 day to 4 hours before birth. 4 
hrs before birth, the space is about an inch wide - very relaxed, you can 
put your finger b/w pelvic bones. this must occur or can't give birth. if 
guinea pig isn't pregnant by age of 6 mos, the pelvis will fuse. if you 
have an adult g.pig, do not breed it b/c she won't be able to give birth 
b/c the ligament won't relax. will need c-section. 
guinea pigs also 
unique in that they respond to shrill noise in a certain way - used in 
auditory research. you know those whistles with the ball in them? that 
noise will make a g.pig freeze. not stampede, not get excited - but will 
stop, freeze, and perk up ears. that means they can hear. a number of 
g.pigs are deaf. this is how you can tell if they hear or not. 


antibiotics - rats/mice can get just about any broad spectrum antibiotic. 

guinea pigs, however, can't. gram positive organisms will wipe out their 
flora and cause toxicity and kill them. much less so but still sensitive 
are hamsters, chinchillas, even rabbits - be careful (double check notes 
re: gram +/- stuff)

rabbits are not rodents. they are lagomorphs. 
rodents have four incisors. rabbits have 6. the peg incisors are behind 
the upper incisors. 

picking up rabbits - be careful - strong, muscular 
but weak bones - will kick when nervous (thumping feet when wild rabbits 
are in danger) and can break their own backs. that's not at all unusual. 
if you do this, clients and rabbit will be pissed. do not pick rabbits up 
by the ears. ever. that's not good. 

what disease would a rabbit have if 
it were sick? pasteurellosis. can cause almost anything - abscess, 
diarrhea, upper respiratory disease. if you see sick rabbits, give 
penicillin. pasteurella very susceptible to this.

mucoid enteropathy 
also occurs in rabbits - sometimes in young adulthood 6-16 weeks of age - 
stressed rabbit can get violent, fluid diarrhea and die of dehydration. 
best tx is to cut food back in half. for a few days. tx diarrhea 
symptomatically. (replace fluids?)

rats do not vomit, they have limiting 
ridge in stomach
rabbits do not vomit.
why is this important? well, 
usually you withold food overnight prior to surgery. you should not do 
this for rabbits - they will develop metabolic problems even from a 12 hr 
fast, and there is no reason b/c they won't regurgitate anyway. also 
consider not fasting any rats b/c they don't vomit either. mice ok to 
fast for a few hours.

fasting rabbits causes severe possibly lethal 
acid/base imbalance.

rabbits hold their breath - masking them down is 
difficult. they hold breath then suck in SO much it can be almost lethal 
dose. palpebral reflex is different. don't jump into doing rabbit 
anesthesia - get someoone to show you stuff. very prone to laryngospasm 
and difficult to intubate rabbits. 

rabbits have coccidiosis - it's 
there in almost all rabbits - causes mild diarrhea sometimes. some sulfa 
drugs are very effective for this. 

ferrets are more and more popular 
these days. one disease the ferret might have - influenza. they get human 
flu. if sneezing and wheezing ferret comes in you could get the flu from 
it. ferrets are used in flu research a lot. 
ferrets are induced 
ovulators like cats, rabbits, meadow voles. (don't need to know meadow 
vole). seasonal breeders, seasonally polyestrous. sexually active in 
spring. ferrets prone to hormonal problems, sometimes cause chronic 
problems and many recommend early neutering. probably that's a good idea. 
pet ferrets are liekly to have hormonal problems. 

many vaccines are of 
ferret origin - MLV vaccines of ferret origin can't be used in ferrets. 
if you use ferret origin vaccine in ferrets, the ferrets will die. 


moving on to bigger creatures.

primates - 

new world  v old world - 
differences?

old world have cheek pouches, ischeal callosities
new world 
- many have prehensile tiles (old worlds do not)

primates need vitamin C 
and D3. this is important. we used to use a rule of thumb - 2 legged 
creatures need vitamin D3. chickens need D3. that may not hold true 
though. primates groom eachother socially, and hsould be housed together 
if possible, social creatures.

the higher on evolutionary scale, and 
larger, the less likely to have multiple births. marmosets have twins, 
triplets; macaques rarely have twins; gorilla, almost unheard of

sex 
skin - visible, dramatic esp in baboons, some macaques - looks like it 
might be abnormal if you'/re not aware. skin is fragile and vulnerable to 
trauma at this time. can see a huge laceration in sex skin and when  the 
sex skin regresses it is just a tiny nick.

TB: all primates get this. TB 
and malaria are big diseases threatening people and TB is a problem with 
macaques, especially rhesus monkeys, which are very susceptible to TB. 
not likely to be carriers but can be, and when they are they shed. many 
people carry TB. someone wrote that it is more likely to get TB if you 
are susceptible, walking through the KoP mall than walking through 
primate rooms, b/c you wear masks in primate rooms to protect the 
primates from TB and measles (and secondarily to protect yourself).

some 
hemorrhagic fevers and viruses can be carried by primates.

Herpes B: 
herpes viruses have a "active" or "fatal" host, and a "carrier" host. we 
are the fatal host of Herpes B and rhesus is the carrier host. 

herpes 
simplex: we are the carrier host, owl monkey is the fatal host

if you 
see a macaque esp rhesus with any ulcer on any mucous membrane, hope you 
didn't touch it b/c it could be herpes B. your chances of getting it even 
if you touch ulcer are under 50% but it is LETHAL and we can't really 
treat it and you do not want to get it so be careful.

if you have an 
ulcer, avoid new world primate colonies b/c you are the carrier host and 
the owl monkey esp is lethal host.

always wear protection when working 
with primates:  (not that kind of protection) - protect your mucous 
membranes from being splashed with saliva - eyes, skin, any cuts or 
abrasions you have, wear gloves, wear face shields, rubber gloves and 
heavy gloves; decontaminate the area if there is an exposure.

use 10% 
chlorox - effective against most viral agents

Freund's adjuvant - is 
used as an adjuvant, to stimulate immune system, often in conjunction 
with antigen to cause Ab response. some vaccines use this. this has been 
used in humans but no more b/c caustic, painful, uncomfortable. be 
careful when using it. 

but, how do you test NHPs for TB? always test 
them. the way you do it is to put mammalian tuberculin intradermally. do 
NOT use PPD. you will get false negatives. you need to use the mammalian 
tuberculin injected ID. look for induration, swelling - hard swelling. 
anywhere on skin ok but commonly done and most easily on the eyelid b/c 
you can easily go ID there, and you can easily see the eyelid when the 
monkey stares you down when you come to check the reaction. 

Freund's is 
a killed tuberculin, but exposure to this will immunize the individual to 
TB to some extent. some people are immunized this way - BCG vaccine - in 
europe. but once exposed to this Ag, you are hypersensitive to it any 
time you get exposed in the future. so if you get infected you will have 
immune response; or if you have skin test you will respond as a positive. 
an animal will do this too.

a visiting scholar from China came here. he 
had to get TB tested to get cleared to go into the primate rooms. his 
test was of course positive. animals will test positive this way too. if 
an animal tests positive, make sure prior to euthanasia that it wasn't 
immunized or ever injected with Freund's adjuvant. 

now, when someone is 
vaccinated with BCG and then tests positive, how do you tell if they are 
really positive? well, humans with TB form calcified granulomas which 
show up on radiographs. NHPs do not form calcified lesions so you can't 
even test that way in NHPs. if an animal was vaccinated/injected with 
Freunds, don't even bother testing b/c it will test positive.

Pigs: what 
to know. people like white skinned, hairless pigs for research purposes. 
the yucatan is a mini pig with white skin, little hair. drawing blood 
from pig - ear vein, also pre-cava is easy, common; up in the triangle of 
the neck. but pig has phrenic nerve on left so do not try to draw blood 
from left side of pig neck. always go in on the right side. 

pig 
restraint - use a pig sling (patapento sling? )
pigs are very social; 
they *need* social enrichment. they like to interact. if theycan't 
interact with each other, they must have toys. they can bowl with 
tremendous accuracy and quite some speed. 

erisypelas - diamond shaped 
raised red welt - occurs in pigs and people can get it from them. 

Goats 
- unique thing about goats is they have tiny RBCs so automated cell 
counts are screwed up if you don't set them correctly. so know red cells 
are smaller so this changes other parameters. they are also higher in 
number b/c you need more b/c they are smaller.

sheep: know husbandry 
things - if you bring them inside fully wooled, shear them. trim their 
feet. sheep are used in fetal research. intrauterine surgery was mainly 
developed in sheep. 

sheep get contagious ecthyma/orf - lesions on mms - 
lips, commisures of feet - people get it too; one tech here got it - it 
was a dramatic lesion. one of the zoonoses to know about.

q fever - 
rickettsial organism - causes little clinical problem in sheep, severe 
problems in immunocompromised or stressed humans so often serious 
problems in hospitals, etc. organism is concentrated in placental 
tissues. the unique thing about q fever is the tests we have are Ab 
presence tests, there is no good skin test; animals with Ab aren't 
necessarily shedding; animals w/o Ab aren't necessarily shedding but 
might be; test is a waste; should buy sheep from a herd that has a 
history of absence of Ab and should be aware of the problem in general. 
people using sheep here at Penn want to MRI them, and the MRI machines 
are in the hospital, so you have to be careful to protect people.

what 
should you know? how much blood can you take from an animal? rule of 
thumb: 7% of your body weight is blood. calculate blood volume. you can 
take up to 10% of total blood volume without causing any hematologic 
problems or any undue stress. you can take up to 20% without being life 
threatening. over 20% is life threatening. remember those numbers. 
remember that blood regenerates or is produced over 3 week period. you 
can take 10-20% of total blood volume over 3 weeks. do not exceed that. 
if you need normal blood parameters, do not exceed 10%. remember that. 
that's good in everything from mouse to elephant.

gestation periods of 
common animals - you should know these
they fool you.
hamster: 14 days

mice/rats: 19-21 days
rabbits: 31-32 days
rhesus: 150 days (5 mos)
cow: 9 
mos
pig: 3 mos, 3 weeks, 3 days (111, 114)
horse
elephant: ? 24 mos?


chimpanzees - why are they used in research? 
if you use one in research, 
per federal law, you are financially responsible for housing that animal 
for the rest of its life and you can't euthanize it b/c you do not need 
it anymore. but they are very valuable for some research uses - they are 
used in hepatitis research, as a model in some AIDS research. 

it would 
be fair to ask us to draw blood from any common lab animal and you should 
know where to get the blood from safely from the common animals.

guinea 
pig: clip toenail real short, take a drop  - that's one way. if you need 
more blood, there is an ear vessel you can use. also the saphenous.


mice/rats: medial canthus of eye with pipette while under sedation; also 
lateral tail vein

rabbit: lateral ear veins; central ear artery

rhesus 
monkey: femoral triangle, saphenous, jugular

these are the obvious 
things to know for the exam. there will be some "common sense" questions 
from Norm Peterson. he makes you think a little. it is common sense, 
though. nothing to memorize. like, know that mice are smaller than 
elephants, and if you need a lot of generations you want animals with 
short gestation, etc. 

which animals come naturally as SCID? SCID mice, 
SCID dogs (colony here at Penn). 


----end----