The exact method of translating would be the issue - most (or probably all, at least as far as I know) animals don't have a spoken language like we do and rely more on body language combined with scents and noises. There are a few animal species that we can communicate with - dogs and other domesticated animals can learn and respond to basic words. Great apes can be taught to communicate with humans through symbol books and sign language.
Presumably the "translation" you receive would have varying levels of refinement. In all likelihood you would receive mainly emotion words: hungry, scared, happy, ect. That's not the say that animals aren't capable of more complex emotions - for instance, elephants have been known to touch the bones of their dead in a way that may be their version of grieving. Mammals such as dogs are certainly capable of feeling love.
One thing I've seen in the other answers and comments is the idea that animals aren't capable of abstract thought. This is not entirely true. There are a few important measures of intelligence that involve some form of abstract thought which animals pass - recognizing yourself in a mirror is one. Elephants, dolphins and great apes can do so, so they'd likely be the species most effected by your machine. Creating tools is another (both dolphins and chimpanzees do so).
A note on dogs - While intelligence levels vary, they are not at the level of the above animals or humans. What dogs are really good at is communicating with humans. As an evolutionary tactic, they basically outsourced their brains to humans. So while they may be communicating to you very clearly what they feel and be able to respond to you, it's more a sign of how close they are to humans than how intelligent they are. That being said, there's occasional dog who's been breed to think independently (border collies are an example) that will be unusually intelligent.
For the species effected, I think it varies how much will change. Laws may be enacted to protect these species, although some already are protected in some way. I doubt that their lives would be considered equal to humans, but they would probably receive special protection. Elephants would still be killed by poachers. Given all the terrible things humans do to each other, people probably wouldn't stop hurting intelligent animals.
One thing that might change is using them as test animals in labs (effects mainly great apes). This may be banned or may become more tightly regulated.
On the whole, I doubt much would change. Humans still don't always treat humans who are different from them well, and I doubt that they'd treat animals much better. Besides, we already have a fairly good grasp of animal intelligence levels, that this wouldn't be to new. Possibly there would be more public support for animal protection? Or maybe people will doubt the data of your machine.
How widespread your translating technology is will also be important.