I did have this one dream over two decades ago, where I consumed some dog food and was abruptly transformed into a Golden Retriever and was running in a field.
Most of my dreams are bad dreams, or nightmares. If animals are involved, lately, it's often something like: oh, okay, we have cats. Wait, that's too many cats to take care of. We can't do this. How did it come to this?
There will be mice, guinea pigs, kittens, dogs... often it involves stressing about what they have access to, keeping small critters safe, where to put them, etc. Sometimes my cat is lost, and I have to look for him to make sure he's safe.
Rarer, I will dream of not being in this human body, or in a shapeshifting mix, where I can fly and access impossible spaces. Those are much better.