Eh, it's extremely unlikely that dogs have developed any totally new types of emotions during the domestication process. More like they were easy and useful to domesticate because as intelligent, mammalian, social pack predators, their ancestors were already a good fit for humans, mentally.
There are papers/studies that show that dogs have facial muscles that wolves lack that effectively give them expressive eyebrows. You could argue this is the result of human selective breeding but it does allow them to portray emotion in a way wolves can’t. Not sure how one would define “new emotion” but certainly their ability to communicate emotion to people at least has changed/increased.
Adding on to this, there’s evidence that domestication involved selecting for genetic abnormalities in dogs that are analogous to Williams Syndrome in humans, a disorder which is known to cause pro-sociability, a strong sense of empathy, and relatedly, anxiety.
I’d argue we have pretty good evidence that the emotional processing of dogs has been dramatically altered by domestication.