Cesar Millan is under attack from a former employee who claims she was steamrolled by a runaway llama while on the job.
Adriana Barnes -- who was director of Cesar's dog rehab facility -- says the "Dog Whisperer" worked with many kinds of animals, but untrained employees let them run wild ... according to a lawsuit she recently filed in L.A. County.
Barnes claims the "Dog Whisperer" forced her to work 12-hour days with no lunch or bathroom breaks, and since most of the other employees were inexperienced ... the bulk of the work fell on her shoulders.
In the suit, she claims things got so bad that she was bitten 5-6 times by dogs and on one occasion she "was trampled by a llama."
According to the docs, obtained by TMZ, Cesar fired her when she confronted him about the work conditions.
Barnes says in the suit ... the stress of getting canned caused her to overdose on anti-anxiety pills, landing her on life support for 3 days.
We've reached out to Cesar ... no word back yet.