Er, basically anything you find on the effect on humans, it's the same for rats. Only their brains are itty-bitty, so killing a few brain cells does a lot more damage for them than for humans even.

The main problem, though, is their respiratory system.  The two biggest health problems in rats are tumors and respiratory infections, and he's increasing their odds for both of them with smoke.  Is this guy planning on spending the money on a vet when (not if, if he keeps this up) they wind up with a massive infection?  Rather than linking to a couple articles, if you go to google and search for "rats respiratory" (no quotes) you'll find all kinds of hits, it's that big a problem.

My friend, Sarah, had her BF take care of her rats when she went somewhere and he's a major pothead and he blew smoke into her rats lungs and they died b/c of it.

You know, I accidently ran across a scientific study of marajuana and rats several months ago...I will see if I can find it on purpose
I don't allow smoking of any kind around my kids or rats.

Well I did a Google search and found this image:

I managed to convince him that smoke is bad for rats and he told me he didn't know and from now on he won't smoke ciggarettes, cannabis, or burn incense or anything around them.  He still seems to be into getting his dog and rats "high", and insists that if smoke is bad why not feed it to them, so I pulled up a response from this thread about the toxicity level in drugs being much more in small animals than humans.  I personally don't think he should be owning rats if the only activity he enjoys with them is consuming illicit drugs.

Your right Judith....I  said  that out of  anger.....and now on  to the next one:

He didnt know?   

Um....DEARPIE? MASKING TAPE FOR MY MOUTH,  PLEASE?               

*It would save time for  the mods  soo  they  dont have  to EDIT  this! GAH!*

he might be your friend and all, but he needs to stop, just as much as he needs to stop abusing his rats. you might want to consider getting help from law enforcement, or drug re hab.

Blowing any kind of smoke into an animals face is abuse. Feeding an animal controlled substances is abuse. That being said Marijuana is not the evil most make it out to be!! I live in Vancouver BC Canada , and anyone who has been here will tell you that half the city smokes pot! People walk down busy streets in daylight smoking pot , there are pot smoking restaurants all over the city (two within walking distance of my home). and were not all dying from cancer etc.
Pot does have a higher amount of tar than cigarette's (1 cigarrette sized doobie = 10 mild cigarettes) but it does not contain the other 1000's of chemicals that cigarettes do, pot smoke is far less harmfull than cigarettes!!!!!! Have you noticed that when people smoke pot they cough, (sorry i can't remember the word I'm thinking of - it's what you call things that cause healthy coughing to clear lungs and passageways (and no I'm not stoned! LOL)) it is a healthy cough that cleans out your lungs etc. In fact there has been anecdotal evidence that people who smoke pot and cigarettes get less damage from the cigarettes cause the pot is cleaning them out. So i personally believe that pot is far less harmfull than cigarettes or alcohol!!

Now that I've finished my rant about pot not being 'evil' , I'll add no animal has the ability to ask its owner to get it high! You do not have the right to decide for your animal wether or not to risk it's health , emotional wellbeing , etc. Cause you think it's funny to get it high , i seriously doubt that Marijuana effects animals in the same way it affects humans you do not know what you could be doing to it!!!!! So save your pot for yourself (and please try to smoke it in another room) and you can laugh at yourself instead!!

I work for an insurance company, and you wouldn't believe how many of the nurses smoke (it seems like an oxymoron to me... nurses and smoking).  They see people all the time dying of lung cancer and everything, and still do it to themselves....  so I guess people 'not thinking' that blowing pot smoke into animal's faces wouldn't hurt them really isn't all that far fetched.     
And when I had my first rattie in college (before the internet and all the great info), he lived in a 10 gallon tank on cedar (although he was trained to come when I called him and my roomie loved him, so he just used the cage for a litterbox, he could come and go as he pleased), he was an only child, ate seed mix, I would dip my finger in my Coors Light (my taste in beer has since improved, hee hee)and let him lick it off (two dips was all he was allowed, he weighed about 2 pounds), my father fed him spiced gumdrops (Dad loves them and thought it was awesome to sit with Omar and chow on the candy together), pretty much every vice known to ratdom.... and he lived to be almost 4 yrs old with never so much as a sniffle.  But I never thought a bit of beer would hurt him, because gallons of the stuff never hurt me!!!!!!!  Who knew. 

omg!   i understand this person is your friend but he really needs help him and the poor rats. i have an idea but it is wrong and i dont want my message to get deletd. you MUST get those rats OUT!  if hes doing drugs who knows what he may do when stoned. he could get high and decide to see how small he could squeeze his rats or how high they can fly(thrown) and drop them. this is not safe. i recomend getting the rats out (offer to take them off his hands) and then get this poor person some help. drugs are lame and people who do them have a serious problem and need help. stay friends w/this person but only if they start rehab. support them during rehab but if he starts up again you need to stop seeing this person. as a last resort you could call the cops or aspca?as for what i think of this person if i said it out loud i would be expelled from this site forever.      

Yes, sarah-beth, calm down a bit.  Pot is not hallucinogenic unless you do a WHOLE LOT of it at once.  You're mixing it up with other drugs.

I don't smoke pot either (I can't stand anything that involves inhaling a substance, my lungs are way too delicate), but I don't think it makes someone a bad pet owner if they do.  They just need to NOT do it around their pets.  They also don't need rehab unless it's a serious problem that is interfering with the rest of their life - for most people, pot is not addictive, and for most people who do it occassionally it doesn't effect the rest of their lives in the least.  Unlike, say, many people who get addicted to completely-legal cigarrettes and can't concentrate or start shaking if it's been too long since they've had one.  Heck, some people even get that badly addicted to caffeine.

Folks, not to rain on the parade, but the issue at hand is not this person's life choice, or even the legality of the substance he chooses to smoke, but the safety of his pets, period, and what can be done to help keep THEM healthy. Thanks.

Doesn't matter if it's pot, cigars, Marlboros or incense... smoke is bad for rat lungs, period.