I found the following blurb in Guatemala Citys Nuestro Diario. Please pardon any translation errors.
Adopted by a Monkey
A female monkey was seen carrying a baby dog on the branch of a tree in a rural zone of the Indian state of Jammu and Cachemira. According to the local residents, the monkey lost her baby and adopted the puppy in its place to satisfy her maternal instincts.
Its an interesting story, although I would categorize the locals rationale for the adoption as speculation. I did a quick google search, and was surprised to discover that with the exception of Koko the gorilla, it is actually much more common for pets to adopt primates than vice-versa.