The only ones I’ve seen first hand are many dogs and a couple of cats who seemed to enjoy the taste of their owners’ mary jane stash. They definitely did not enjoy the results of eating said mary jane.
Hmm, what else, now that I think about it dogs don’t do well with coke or amphetamines, either, though I haven’t seen more than a couple of those.
I understand that elephants will also seek out fermenting fruit, or human-made liquor. I recall reading many years ago of an incident where a herd of elephants invaded a village, ripped open a building to get at the illegal moonshine operation inside, and after slurping up the supply did further damage to the village staggering drunkenly into walls and such.
I also note that Wikipedia has a short article on Zoopharmacognosy (animal self-medication) which includes this:
I’m glad I didn’t have to be the first one to post the link to the effects of drugs on spiders. Very informative. Anyone ever get any more information about the crack spider’s bitch?
Many common antibiotic drugs (the …cillin or …mycin ones, for example) are effective on both humans and common domestic animals (horses, cows, pigs, cats, dogs).
Sedative/tranquilizer drugs have similar effects on humans & other animals, but side effects may be serious. For example, some horse tranquilizer drugs are misused by humans for their mind-altering side effects (They might do this to horses too, but we can’t tell.) Dosages are also often critical.
With painkillers, many seem to affect both humans & and animals. But appropriate dosages are often critical – so much so that many are not used on both. The original one, opiates (like opium, morphine, heroin, etc.) works on humans, horses, cows, pigs, & dogs – but not cats! (It works on cats – too well. They can’t excrete it, so t stays in their system, eventually overwhelming them, usually fatally.)
I have this image of a drugged spider shaking and clawing at itself, and saying to another spider “Humans! I’ve got humans crawling all over me!!”
I’ve observed cats and dogs high on marijuana on a few occassions and the only obvious visible effects that I noticed was a sort of lethargic behavior. ie: They slept more than they normally would.
Well, at least, the dog did. There also didn’t seem to be any visible after effects, either.
He may have had the ‘munchies’, but most dogs that I’ve ever owned seemed to be hungry all of the time, anyway. 
It was kind of hard to tell with the cats, though. IMHO, cats seem to be high, all of the time. 
And before all of the PETA dopers start up a lynch mob, the animals weren’t mine,
and I didn’t get them high.
(This happened, many years ago.)
One of my previous dogs has been given prednisone, antibiotics, and when both previous dogs got stung by bees (the german shepherd was trying to catch and eat them - guess she got one), childrens’ benedryl was recommended. Knocked them right out but they were fine by the rest of the day.
I don’t have a cite but I think ibuprofen (advil) is very bad for dogs.
A dedicated stoner friend of mine had a cat that was exposed to great billowing clouds of secondhand reefer smoke more or less all day every day.
That critter was paranoid. She hid all the time, and then would strike from unexpected directions. She popped up in between the couch and the wall and clawed the crap out of the back of my head many times.
So, at least when it comes to cats and weed, people drugs turn animals into psychotic ninjas.
Giving PCP to a gorilla that had been trained to use a spear, and then forcing it to fight a grizzly bear would be awesome.