The book is Somewhere a Voice, a collection of seven stories by Eric Frank Russell; you may have read the 1965 Dennis Dobson hardcover or the 1966 Ace paperback or the 1968 Penguin paperback.
The first story has the same title as the collection, "Somewhere a Voice", first published in Other Worlds Science Stories, January 1953, available at the Internet Archive.
Spacewrecked on a jungle planet:
They crawled, walked, tottered or jumped out of the battered little lifeboat, each according to his or her mental or physical condition. There were nine of them. The lifeboat had been designed to carry twenty but only nine emerged and only two remained within it.
All around towered the tangled jungle of a world notoriously hostile to their kind. High above burned the intense blue furnace of a sun that lent their faces a ghastly glow and made them peer through lids narrowed to the minimum. The air was thick, cloying, full of vegetable smells and vaguely reptilian but unidentifiable stenches. The jungle brooded in utter silence, waiting, waiting, waiting.
Sammy loses his legs:
Racing downstream to keep pace with him, Mallet sprang waist-deep into the water, grabbed Sammy by the hair and drew him into the bank. Bending, he grasped him under the arms and lugged him clear of the river.
Or part of him, all but the lower legs. There was nothing below his knees but pulses of blood from severed vessels.
The woman, Mrs. Mihailovik, does not survive; the only survivor is the dog.
The second story is "Seat of Oblivion", first published in Astounding Science-Fiction, November 1941, available at the Internet Archive.
The scientist explains his invention:
"But this can liberate the psyche of any person. It's a major break-through."
"Who wants to liberate his psyche? Who'll pay to have it done and how much will he pay? Hell, pigs can fly these days so what's the use of an automatic psyche-liberator? If I go to see Maisie in the south of France, I go in person, flesh, blood, clothes and all. What would be the sense of sending her my astral body? She couldn't have fun with a ghost."
"You forget, said Wane, his voice rising, "that the gain in life-power is so great that the affected personality can escape and literally take over any other living body it desires, ejecting the natural owner forever—unless, of course, the owner happens to have received treatment giving him power equal or greater."
"That's body-snatching," defined Blenkinsop with another obese grin. "You've developed three or four excellent things in your time but now you've slipped up. I can't make two percent out of a mechanical body-snatcher and I'm not interested in the thing."
"You go off at irrational angles," Wane protested. "I only contemplate the legal transfer of bodies."
"Legal?" Blankenship choked as he tried to laugh with a chestful of cigar smoke. "Whose bodies can be confiscated legally? And for whose benefit?" He prodded Wane's middle with a thick finger. "Who's going to pay for the transfer, who's going to get the money and where do I come in?"
Eying him with unconcealed distaste, Wane said frigidly, "Last Thursday, Collister died. He was the world's leading cancer specialist. On the same day they executed Bats Maloney, a criminal. Collister's brain remained alive to the last but he was physically worn out by a lifetime of service to humanity. Maloney died as an incurably warped and antisocial psyche inhabiting a coarse but strong and healthy body."