No.
Dolphins traditionally do not use computers, but when humans are testing their intelligence sometimes they set up sensors that the dolphins can bump with their noses to indicate one of two options.
No, they are dolphins
to study dolphins
dolphins do use them. they use them to catch fish and to tear things apart.
No mammals other than humans routinely use computers. However, some monkeys or chimps have been trained to "type", though whether they meaningfully comprehend what they are doing is not known. For example, if I train Chimp 1 to type "baby", does the chimp know that b-a-b-y means an infant?
They use echolocation!
1. You can use computers to learn new things.
Bats and Dolphins both use sound to navigate.
Italy is a country that does use computers. In this technical age, all developed countries in the world use computers.
they use computers to keep check of what they sell
Dolphins are free swimming and don't use any shelter.
All mammals use a computer: their own brains. However, in terms of analog and digital computers, humans are the only mammals that choose to use computers. Primates and other mammals can certainly be trained to use computers to perform simple tasks (mostly through game-play), however it's doubtful if they gain any real benefit. They certainly don't use them through choice.