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Howard "Bud" Hughes
SmithKline Beecham guy

he's here to 
discuss anesthesia in lab animals
we'll talk about rat, mice, gpig, 
rabbit, NHP. of course, other spp are also used in labs; hopefully 
anesthesia for other spp will be covered in anesthesiology.... :)

the 
most commonly used spp in biomedical research are the rats and mice. they 
make up 85-90% of the animals used in biomedical research. 

mice -
to 
get a mouse out of a cage will rarely cause severe human injury.
if you 
can handle a mouse appropriately you are less likely to cause injury to 
it or yourself. 
most lab animals are docile, easily restrained.
just 
pick mouse up by his tail and put him on a surface where he can get some 
traction - rubber pad, cage lid - so he can try to pull away from you 
instead of trying to run up your arm and maybe bite you. then grab scruff 
of neck with the other hand. hold that b/w thumb and index finger and 
tail b/w pinky and palm and you have the mouse in a one hand hold. 

can 
use gavage tube to provide oral feedings.
to collect blood, use venous 
plexus of the infraorbital sinus - stick a capillary tube in the lateral 
canthus and stick it back there. you could anesthetize and do cardiac 
puncture. you could snip off end of tail. 
when you use eye bleed, just 
put pressure over it and bleeding will stop.

can give IP injections
can 
give IM injections
can give SQ injections
can do IV injections into 
lateral tail vein with 27 ga needle; also can collect blood here. 
butterfly catheters are good to use here. to facilitate vasodilation, dip 
tail in warm water (rodents lose heat in feet, ears, tails) or stand on 
heating pad, or put animal in a warm area for a minute or two (35 C)
one 
thing about using this vein - when you do this repeatedly, you can cut 
off pieces of hair as you go through and get hair emboli.

you use the 
same one hand grip to do vaginal cytology. use pasteur pipette. 

rats 
aren't just big mice. they are different. you can pick up a rat quickly 
by gripping the base of the tail - like, just to pull out of cage, or 
move cage to cage. but you can't hang from end of tail or the tail will 
come off and you'll be left with a tail. especially embarrassing if it is 
a pet and you have to follow trail of blood to recapture. most rats are 
fairly docile, used to people. so just pick up the rat over his shoulders 
and hold him. sort of cross front arms of rat under his chin. support 
hind end if large rat. anyway, can use same one hand grip to do all the 
same stuff with mice. tail vein used very commonly for blood collection 
and for injections. also can clip toenails to get blood. can anesthetize 
to get blood from saphenous vein.

Hamsters - these will bite you. some 
inbred strains are just downright mean. if you put 6 in your apartment 
you won't have any problems with burglars. you walk up to the cage and 
they do a godzilla impression. kind of intimidating. to handle these guys 
you can try the gentle herding approach (by the way - feed hamster on 
floor b/c will not use a feeder) or push down on hamster against bottom 
of cage, grab as much skin as you can in sort of a mega-scruffing 
technique, and you can hold him that way. to get blood - could do 
retroorbital or cardiac. they have no useful tail. IV injections are not 
really possible or practical. SQ, IM, IP are available. 

most common 
anesthetics in these animals are still Pentobarbital...don't worry about 
doses. thiobarbiturates are not used - cause megacolon. the pentobarbital 
needs to be diluted down 1:10 in saline or saline alchohol mix. give IP. 
still commonly used. however, remember, these small animals have such 
large surface area they get hypothermic really fast esp if you open the 
abdomen so you must keep them warm, b/c anesthetic dose will rapidly 
approach euthanasia dose in a hypothermic animal. body temp can drop down 
5-10 F if you open them up. use heat lamps, recirculating water blankets. 


partial list of drugs capable of producing microsomal enzyme function:

steroids, ether, halothane, DDT, dilantin, barbiturates, aromatic oils 
from wood, diphenhydramine, etc etc. so you have to consider that these 
things may change your required anesthetic doses based on P450 
metabolism. old animals need lower dose. males need lower dose than 
females (mice).

if there's any drug that is really the handiest to use - 
ketamine - for procedures in most lab animals. ketamine esp mixed with 
xylazine - 50 mg ketamine, 5 mg xylazine. give IM or IM. will work well. 


another anesthetic commonly used and strongly recommended against is 
ether. ether is flammable - 1:10,000 uses causes explosion. you don't 
want to be in there when it goes up. use only under certified fume hood 
if you must use it. it is cheap, easy to get, very safe for the animal 
unless it explodes. so people like to use it. but, don't use it. if you 
soak cotton in ether and put it in the jar, put a mesh or something over 
it so it doesn't get onto the animal's fur, esp if you are going to be 
using cautery on it. but also can potentiate hypothermia this way. 


chloroform - don't ever use. carcinogenic for you, acute renal tubular 
necrosis in mice from very low fume levels. also hepatic necrosis.

bell 
jar, cotton, mesh - use isoflurane or methoxyflurane this way. not 
halothane - concentration is too high at room temperature.

vaporizer and 
chamber use - can use halothane with that, or whatever else. has exhaust 
system. can maintain via face mask after induction. 3-5% halothane, 5% 
isoflurane, 3% metofane. 

anesthetics are low doses of poisons...so you 
can euthanize with anesthetics if required - can OD on anesthetic, 
although it would be really hard to do with metofane. also sometimes 
people use CO2 for euthanasia, used with a chamber system and a tank of 
compressed CO2 or dry ice. 

other euthanasia methods - cervical 
dislocation is quick, effective - hold neck with thumb/finger, yank tail. 
animal dies quickly. but *never* ever do this in front of a layperson 
because they will freak out. also, in a lab situation, sometimes people 
will do this and then they will pin the animal out on necropsy board and 
stuff - but the spinal reflexes are intact so animal will "jump." it 
can't feel pain of course b/c the brain isn't attached to the body 
anymore. but this is really upsetting to people. rabbits under 1 kg can 
be euthanized this way also. guillotines are sometimes used.  Ugh, I 
think i'm going to be sick. 
anyway. even if you anesthetized animal - 
the anesthesia induction is more stressful than the guillotining if done 
correctly. if done properly, hardly any stress response occurs.

guinea 
pigs - cute, docile, easy to handle. will stampede around a cage and can 
stampede over babies if present. pick up over shoulders like rat, support 
back legs, don't let it flop around. support them well. they are cute. 
they will squeal. to get blood, can cut toenail short (only 3 toes in 
back, four in front), or do cardiac puncture under anesthesia.. IV 
injection in external pubic vein sometimes used. also can give IP 
injection but be careful - do not inject into an organ. hold animal with 
head down so guts fall forward, then inject in lower right quadrant. this 
one gpig got injected with mineral oil into the cecum by accident.


anesthetics - can use most in g.pigs. avoid ether - bronchoconstriction. 
metofane works but takes 20 min to 1/2 hrs to induce and will twitch and 
squeal. halothane, iso are better. ketamine too. 

rabbits: mostly 
reasonably docile. you never want to pick it up by its ears!! can use 
scruff of neck while supporting the hind end. some of the big male 
rabbits can scratch you really bad - they leave long tracks down your arm 
and it hurts so wear long sleeves. to move a rabbit around, use football 
hold - tuck head under your arm, hide eyes. if you fail to handle a 
rabbit correctly or even sometimes if you do -= they can break their 
bones. they have light, fragile skeletons and very strong muscles. this 
allows them to hop rapidly from one place to another and avoid predators 
because almost any predator will eat a rabbit. they have white muscle for 
lactic acid metabolism. so when the rabbit struggles it can kick so hard 
it breaks a vertebra or two. sometimes these animals will subluxate and 
end up with bladder paralysis and other things. this isn't always an 
indication of mishandling. a rabbit can just kick out around in his cage 
and do this! if you have to anesthetize a rabbit, this can happen in 
excitement phase of anesthesia so warn clients this could happen. 
ears: 
there is an inner marginal ear vein, and outer marginal ear vein and a 
middle artery. don't give something IV into the artery (duh). there are 
special rabbit restraining apparatuses with "kick plates" to lessen the 
possiblity of it injuring itself. also can use cat bag or make rabbit 
burrito out of towel. 
butterfly cath in outer marginal ear vein is great 
for blood collection or IV injection. if you warm the ear you can dilate 
the vessel. can tape this in place and then use as catheter. can use 
central ear artery for collecting blood too - about 1 ml/kg of body 
weight. most animals have 6-7% body weight blood and if you take 1/2 of 
that out you kill the animal; if you take about 1/3 out (2% of its 
weight) you start having hypovolemia so take half of that and you are ok. 
so 1 ml/kg/day is probably ok. can use cardiac puncture (clip, clean area 
first; only as terminal procedure is best; anesthetize first).

barbiturate anesthesia - very very narrow margin of safety in rabbits, 
10-20% mortality rate in rabbits. try ketamine, rompun, gas anesthesia 
better!
if you have a palpebral reflex in rabbit going away, that rabbit 
is dead. you want to maintain the palpebral reflex, and use deep pain 
reflex to assess anesthesia. keep rabbit on circulating water blanket. 
you can intubate rabbits too.

rabbits have a vago-vagal reflex just like 
other animals...squeeze on chest and will take a deep breath...to 
continue stimulating that reflex, put a big rubber band around the chest 
- this can, postsurgically, keep rabbit breathing well.

other anesth for 
rabbits: ket/xylazine IV, ketamine/ace, droperidol, fentanyl.
gas is 
best. NOT metofane b/c rabbits have submersion apnea (diving reflex) and 
you will pass out before the rabbit will. use nose cone or induction 
chamber with halothane or isoflurane. can intubate the trachea. 

no 
ether - rabbits too sensitive, will get laryngospasm and hypersalivate


atropine - 35-85% of rabbits have a circulating atropinase enzyme, so not 
useful in those rabbits. 

other technique - can hypnotize rabbits really 
easily - induce their immobility reflex. you have this happen to younow 
and then...if someone comes up and grabs you quickly, you might freeze - 
primitive response. go up, grab around neck, put back of neck in your 
palm, with thumb on one side of mandible and finger on the other - pick 
it up, hold it with head up, feet down, and it will relax, and release 
endorphins, and just sit htere while you do a PE...you can lie it on its 
back like this, and rub the belly while maintaining neck traction and 
stretching it out sort of - it will stay relaxed. this is what they do 
when they get picked up by wolf or something - endorphin release, 
prevents pain when being eaten. once you induce this, can let go even and 
watch them lay there. if you clap your hands, the rabbit will jump up. 
good party trick. but can auscult chest, trim teeth, clean ears, do all 
that stuff while they are zoned out. 

Monkeys - if someone owns one, 
they are probably in violation of at least one law. anyone with a pet 
monkey is probably insane. most monkeys are mean and have scary diseases 
that can kill you. Herpes B is, says Bud, "serious shit." 
monkeybites 
also really hurt. the monkeys have hands and feet they can use to push 
and pull you around, too. note that these slides are out of date b/c now 
you have to use hoods, masks, eye protection, bunny suits, gloves, 
gauntlets, hats, footcovers, etc. for new world monks, don't pull their 
arms back when you hold them, they'll suffocate. to handle monkey - give 
10-40 mg/kg ketamine first. then you handle it. saphenous vein down back 
of leg is useful for IV inj or blood collection. ng tube is useful to 
feed or put stuff into stomach. can shove pill down back of throat with 
hemostat. 

never give ace, valium to monkey - will make it feel tranquil 
and then it will suddenly arouse and be disinhibited and freak out and 
run around and that will suck.  

narcotics are good to use also. if you 
have to get a baby from mom - give mom 10 mg/kg demerol - she'll get 
relaxed, you can take the infant away without her freaking out or 
traumatizing the baby. then you can reverse with naloxone when you return 
the baby. 

anesthesia - halothane, metofane, isoflurane; intubate with 
human pediatric type ET tube. keep them warm.

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Swine, sheep 
and goats as laboratory animals:
laws, regulations, guidelines.

the 
Animal Welfare Act (AWA) is powerful, affects animals used for research, 
testing, and teaching. doesn't cover genus rattus or mus, or farm animals 
used in ways having to do with food, fiber, livestock management. only 
covers farm animals used in human medical type research. if you're doing 
fetal research, it's covered. get it? 
horses can be considered animal 
under AWA if used to create antibodies. if studying racehorses to 
increase speed around track, not covered. 

why do we use sheep, goats, 
swine?
because they are good models of disease
not because they are cheap 
models of disease
for a long time, dog/cat was used b/c were cheap, 
gotten from pound. when that source dried up, people looked at other 
sources. people were forced to more correctly pick a species to use. 
today, we often buy sheep, goats, and swine in a research production 
unit, they aren't cheaper than purpose bred dogs, so cost isn't so much 
an issue. also there is public sensitivity to use of cat/dog. but 
rationale for selection of animal model should be that it reflects the 
disease you're studying.

miniature swine - new interest. farm pigs are 
huge and difficult to house and feed, costly to have around, hard to 
handle. with minipigs, they are more practical. especially yucatan pig - 
less hair, no adnexal oil glands so less smelly. one problem with typical 
farm pig esp with skin studies is the coarse hair. yucatans have soft 
sparse hair. these have been research bred for docility. you can approach 
the piglets with the sow in the pen and not fear for your life. you can 
actually express milk from the sow. even more dramatic, you can approach 
and handle the mature boars. 

cross b/w yucatan and vietnamese 
potbellied pigs - they took best qualities of both and made a good 
research pig. 

swine anatomy: one must consider especially with boars, 
if not castrated, skin gets very tough, hard to put a needle through it. 
originally, all of them were castrated which cost a lot of money. then 
they stopped doing that. then, it became very difficult to give 
injections. when you don't castrate the males you have this problem. so 
if you're not doing repro work you should get castrated males. one 
advantage of Yucatan is little hair, a disadvantage is they get dry skin, 
and are itchy, and you have to use lotion on them. 

the backfat is deep 
on these pigs. if you try to give in IM injection you can't use short 
needle or you give an IF injection. also, jugular vein is very deep. with 
the jugular vein, typically unless you have a young animal you use a 
pre-caval stick. there is a unilateral left phrenic nerve innervating the 
diaphragm, so if you go too far left, you get a dead pig. go right. 

there are some unique differences about the pig - the thyroid is not 
where you expect it - the thyroid is where the thymus is in other 
animals, and the thymus is in the neck. thyroids in thoracic inlet.

on 
right side - duodenum is there; in pigs, right kidney is caudal to the 
left. you see pancreas, bladder is very small. small intestine is huge

left side: spleen is big, takes up whole side. spiral colon. left kidney 
cranial to right. it's impossible to pass urinary catheter in male pigs. 

there is large preputial diverticulum present as well as corkscrew tip of 
penis. 

physiologically, another thing to consider with minipig vs farm 
pig, the minipig is mature at 6 mos, whereas farm pig not til 8 or 9 mos. 
also blood clotting system not effective prior to 4 mos of age. so if you 
take blood, hold off really well or you get a huge hematoma. 

another 
thing is that often a researcher wants a farm pig b/c it is "cheaper" but 
they want a small pig. so they order a "size" of pig, not an age of pig - 
but they need to know the small animal is much more immature, and immune 
system is depressed b/w 3-4 mos of age so you don't want to use animals 
under 4 mos. 

caging is important. metabolic cages have dividers to 
separate animals but they can see each other; collection area for urine, 
stool, etc. 

another set up - if you feed one pig, within seconds the 
food is gone, so you can have panels separating each pig's portion; then 
you can pull the panels after feeding time so they are group housed. 


it's more unusual to have bedding - but it is preferred - if you can put 
down some straw, sawdust - keep in mind that esp the yucatans with little 
fur need at least four inches of beeding to be comfortable. this is the 
best scenario for them. 

more typically pigs live in dog runs. the 
panels can be removed so that they are together. sometimes pigs defecate 
and urinate on one side, leave the other side clean. allows pair housing. 
flooring - this is the grate type of flooring - realize you will need to 
trim hooves more with this flooring. also with a small yucatan, you may 
find a problem with the sipper tube b/c pig is used to drinking in a down 
position - has to learn how to use waterer -b ut then will like it and 
play with it.

HVAC is important in these facilities. we try to keep 
environmental factors constant. pigs can be odiforous. want 15-20 air 
changes/hr, temp 65-70 F measured at PIG LEVEL. lighting is 12/12 cycle, 
humidity about 45-65%. feeding twice daily is recommended, b/c they don't 
have normal situation can cause themselves to bloat. 

one important 
thing in research animals is acclimatization period - pigs have been 
taken from home, trucked, brought into a weird new place. you need to 
rest them and let them get used to it before putting them on study.

pigs 
are gregarious, they like people and other animals, so best situation to 
control vices/stereotypies is to group house, give toys, and socialize 
with them. one way to see if pigs are being treated well is to see if 
they come up to you. this one pig barnaby would jump into your arms if 
you let him. he was obtained as a baby, and imprinted on staff. 
sometimes, though, pigs will run the other way. but if they've been in 
your facility for a few montsh, and they don't come up to you out of 
curiosity or for comfort, recheck your husbandry practices. toys: 
basketball, garden hosed

it's hard to show how to pick up a pig in 
slides. you hold the ear for a second as a twitch, just to get his 
attention. you don't pick him up by the ear. this is a small pig. with a 
big pig, one person would hold ear, one would hold thorax, one would hold 
butt. but the way she picks it up, looks like picking up dog. main thing 
is making it feel secure. do not let it sense fear. if you are fearful, 
they sense it. bend knees and lift with straight back, btw. your body is 
the most valuable thing you have.

as you know, animals go down and get 
up with hind or forefeet differently. if you put front legs down first 
pigs dno't like it. put back feet down first. 

to herd the pig, can use 
a board to push, or you can walk along and move him with your leg - not 
kicking him, just sort of acting as a wall to get pig to go the direction 
you want.

pigs can be restrained in slings- these are pretty handy. they 
have different sizes for different pigs, some with hydraulic lift systems 
for really big pigs. they can fall asleep in these slings. there are 
openings for limbs and for area of precaval stick. can give premeds, 
other meds, can do oral gavage. there are ties on the legs - put those on 
with double bind so that you don't cut off circulation, just like tying 
in dog for anesthesia. do front feet first so they don't try to crawl 
out. can put lotion on while these pigs are in the sling, too. not 
mineral oil - dries them out more. 

need to know if animal is in pain - 
will be grinding teeth
if goes off feed - probably stressed
if not 
moving, not coming to you - stressed

again, part of preventive care 
scenario is fully understanding the behavior of the animal. pigs have 
personalities, like dogs do. one may be quiet. one may be aggressive. one 
may be friendly and outgoing. know normal. listen to animal caretakers 
who work with them all day. don't blow them off if they tell you an 
animal isn't quite right. 

vaccinations are important - typically lepto, 
erisypelas, bordetalla, pasteurella, hemophilus. should be brucellosis 
and pseudorabies free animals. avoid intermixing farm pigs with purpose 
bred pigs. some farm pigs are exposed to things that research animals are 
never exposed to - research animals do not have natural resistance. 


zoonotic diseases from pigs: 
leptospirosis, erisypelas - controlled by 
vaccination
brucellosis - use brucellosis free herd

intubation is 
difficult - they have a blind diverticulum. it is easy to go up into 
that. 

you can go in, turn tube 90 degrees, then go in, then straighten 
it. b/c tube has a curve, so when you turn it you avoid the diverticulum 
and enter the trachea. 

one thing recommended with pigs for anesthesia 
is to give atropine, b/c they salivate a lot and this makes intubation 
much easier. don't use halothane - use isoflurane b/c it elminates the 
liver toxicity that can occur associated with halothane. still some 
animals do get problems with malignant hyperthermia - can give dantrolene 
prophylactically. if treating a pet or something, consider this 
carefully. 

slide: hydraulic table. it's effective to give telazol 4.4 
mg/kg (don't need xylazine with that), then you can put pig on this 
table, which will raise itself to level of surgery table. then you 
intubate. b/c jaw is so long, you need a long ET tube and long 
laryngoscope blade (or short one with tongue depressor taped to it but 
not a curved food animal blade) and a mouth gag.it's hard to open the 
mouth of a pig b/c really strong muscles. using this, you don't even 
really have problem with epiglottis - you can just see what you are 
doing. cetacaine can reduce laryngospasm.
can mask down in the sling 
after giving the telazol; can use V board to put in dorsal recumbency. 
different people have been taught to intubate in different ways. some 
people put pig on the side, some people do it with pig on the back, you 
get used to your own way of doing it. 

preemptive analgesia - this is 
used to allow you to use less anesthetic and reduce postoperative pain. 
buprenorphine is a good drug for pigs. fentanyl patches not so good in 
pigs b/c of hair - will literally grow rapidly and push patch off. doses 
in handout. 

blood collection - somewhat of a problem. if you need small 
amounts, can use ear veins that are very accessible - to produce 
peripheral vasodilation, stick qtip in oil of wintergreen, swipe over 
vessel - for large volumes, use precaval stick, during which you must 
stay to the right to avoid the left phrenic nerve. 

erisypelas produces 
a red inflamed skin - erythematous patches, in rhomboid shapes. similar 
pattern can be due to septicemia, as in this postoperative staph 
infection. 

slide: barnaby's belly - has an allergic reaction to the 
bedding.
slide: nasty skin lesion - looks like burns. turned out they 
found an autoimmune disease - bullous pemphigus. 
slide: pig with tetanus 
- farm problem

a few models of disease you should know about: pigs are 
good for cardiovascular studies since heart/blood system similar to 
humans; skin similar to ours so burn studies, other skin studies; 
esophageal ulcers, hyperthermia, malignant melanoma.

swine are used much 
more than sheep/goats.

if you understand ruminant physiology/anatomy, 
that's sufficient for understanding this. just remember - RBC much 
smaller in these animals so PCV higher, MCV lower. Goat RBC can sickle 
normally; but if you see rouleaux, that indicates severe disease. as with 
other ruminants, lymphs outnumber PMNs.

slide: goat herd in forest. 

slide: goats in milking parlor

husbandry is important
HVAC should be 
operating well. 65-70 F, humidity 50-70%, 10 air changes/minute.
you can 
house on concrete or raised flooring of metal or mesh, can use bedding 
but not oat straw b/c they will eat it. avoid high concentrates, don't 
give rabbit chow b/c of high concentrate level and copper. w/ sheep and 
goats, remember hooves need trimming routinely. sheep may need shearing. 
to restrain sheep and goats, put sheep in dog sitting position. put goat 
in corner of room. to get blood, you need help. 

preventive medicine is 
important - know normal animals, give acclimation period, PE should 
include fecal, bloodwork, TB test, brucellosis test, and be aware of Q 
fever zoonotic potential..
coxiella burnetti causes disease in people  - 
be very careful esp with pregnant or lambing ewes - placenta/milk filled 
with organisms. try to get coxiella free animals or restrict access, use 
air filters, carefully dispose of waste, and use personal protective 
equipment. 

slide: chronic interstitial nephrosis
slide: leptospira with 
silver stain

when you see a pregnant ewe, and you don't know her 
coxiella status, assume positive and take precautions. food animal vets 
do not use gloves that much. rethink that.

slide: goat with abscess - 
caseous lymphadenitis with pus coming out, caused by corynebacterium 
pseudotuberculosis. common. spreads through herd. 

Orf - contagious 
ecthyma - lesions on hoof and muzzle. wear gloves. this hurts. 
for 
intubation, anesthesia - dorsal recumbency, raised position of head, fast 
prior to anesthesia, mouth small, hard to intubate, be sure to recognize 
trachea is smaller than dogs so need smaller size.

research uses:
AIDs 
stuff, liquid ventilation, fetal research, experimental surgery, antibody 
production.


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