There is no “Catholic view.” It’s not something the Church has ever envisioned happening, and so has not made any statements about it. We can only rely on common sense.
Common sense seems to me to indicate that unless the dogs are service animals, whose presence is necessary to enable your niece to get married, then there is no reason for the dogs to be in the church. If there is no reason for the dogs to be in the church, then they should not be there—especially if their presence will cause a distraction to the liturgy. Distractions can be from congregants oohing and aahing over how cute the animals are; or from congregants annoyed to see them in a church; or from congregants who happen to have an allergy to dogs and did not realize that they would need to protect themselves from an allergic reaction to a dog at a wedding.
That said, if the priest approved of the dogs’ attendance at the wedding, then there is nothing you can do about this. I can only recommend doing your best to ignore the dogs and to focus your attention on the liturgy.
