Interesting...have seen the documentary on youtube this was taken from. Self medication and intoxication is actually quite widespread throughout the animal kingdom, particularly among mammals. Harmaline and the related alkaloids in the ayahuasca vine have been shown to be strongly anti-parasitic, and anti-bacterial, helping purge intestinal worms, and this is one of its medical uses among tribal peoples. So my guess would be the jaguar is ingesting the ayahuasca leaves as a anti-parasitic purgative.
As to the intoxicating effects...that's a tricky one. It's hard to enough to figure out what's going on in another human's head, letalone another species'. Its an interesting theory that they ingest it to enhance their senses for hunting, but this may be more myth than fact. Its interesting though as I've heard similar things about animals ingesting Iboga in the African rainforest.