An oversized Reader’s Digest (?) book about animals

In 1984, I became the proud owner of an oversized secondhand book, nicely illustrated with color and B&W photos, about the animal kingdom. There was plenty of text—in two columns, I think. The cover was a kind of acid-green buckram; the book no longer had a dust jacket, so I don’t know what it looked like. It was a folio-sized book, fairly hefty. It was published anytime during the 1960s or ‘70s. It wasn’t new when I acquired it.

One of the anecdotes—my favorite—recounted in this book dealt with an elephant in Africa (I think it was Africa). A veterinarian or zookeeper encountered a wild female elephant with a badly infected wound in one of her front legs. It had to be treated. So he had her tied up between four stout posts, or a cagelike structure, and once she was immobilized, applied disinfectant to the wound. She screamed and roared in pain and tried to break free, but couldn’t. The next day, he continued the treatment. She cried out, but not as loudly. By the third day or so, she seemed to have caught on that what he was doing was for her benefit, and displayed less resistance. Finally, he was able to complete the treatment without tying her up, and she endured it willingly and quietly. He had to leave her for a while—weeks or months—and when he returned, she gently took his hand with her trunk and placed it on the now-healed leg, just where the wound had been, as if to say, “See, my wound is now healed and I’m grateful that you treated it!”

This book was published by "Reader’s Digest," I think. Or by "National Geographic," or "Newsweek"—something like that.

Marvels & Mysteries of Our Animal World or Animals you will never forget? My family had both when I was a child in the 60s. My mom was a big buyer of Reader's Digest.