"Sanango, a word that essentially means "memory," is a name given to a number of Amazonian plants (Schultes 1979,186)"
"Tabernaemontana sananho Ruiz et Pavon--sanango
In Amazonia, the sanango tree, which can grow as tall as 5 meters, is regarded as a cure-all; the leaves, the root, and the latex-rich bark are all used in folk medicine. (Schultes 1979, 187 ff.) The leaves of the tree are used psychoactively as an additive to ayahuasca and also are combined with Virola spp. to produce an orally efficacious hallucinogen. The plant is also called uch pa huasca sanango and it is known as a "memory plant," a reference to the fact that its inclusion in a psychoactive preparation cases a person to better remember the experiences he or she has has while under the influence of that preparation. It is added to ayahuasca so that a person can, afterward, more clearly recall the visions he or she saw.
In Ecuador, the plant is known as sikta and is available in raw form (short branch pieces) at local markets.
The Jibaro drip the freshly pressed juice intothe nostrils of their dogs so that they may be better
able to locate prey. The plant is also known as yacu zanango.296
It is rich in alkaloids (Schultes 1983a, 270*)."
"Tabernaemontana tetrastachys H.B.K.-uchusanango,
saticu
The Makuna Indians call this plant bee-e-ge and use its latex as stimulating eyedrops (cf. Tabernanthe
iboga). A few drops is said to dispel tiredness and sleep (Schultes 1979, 189)."
from
The Encyclopedia of Psychoactive Plants by Christian Rätsch.
Now we can see the correlation to the statement of sanango being useful for lazy hunting dogs.
I'm guessing Tabernaemontana sananho is synonymous with Tabernaemontana undulata?