Dr Ed Peters, a Canon Lawyer who I guess could be termed a real "Liturgy Cop", who blogs at In the Light of the Law, raises the the issue of a "Joisey" pastor who brings his dogs to Mass with him:
A saying in canon law runs thus: "There's no law against it till somebody does it." Well, somebody's doing a new "it", so maybe it's time for a new law.
Per the New Jersey Herald News and the Te Deum Blogspot, Fr. Louis Scurti, a campus minister at William Paterson University in New Jersey, "brings his two dogs everywhere [oh?] and that includes Sunday Mass." His pair of pooches set themselves up in the sanctuary during Mass, "making people feel included" [huh?] and providing a "symbol of domesticity" [double huh?]. Although the apparently untethered canines "have been known to growl" at late-comers, Fr. Scurti assures us that his dogs "don't remove the sacredness of the liturgy at all."
The dictates of common sense are hard to put into words. If one has to explain to a pastor why his mutts don't belong in Mass, one goes into the effort with the uneasy feeling that such words might be wasted on, well, someone who needs that kind of thing explained in the first place. But most folks can tell the difference between a liturgy and a living room, and many Catholics are out of patience with priests (granted, in shrinking numbers) who still treat the Mass as their personal property. [snip] Read It All
The Curt Jester takes umbrage at criticism of dogs at Mass and has some thoughts as to their potential usefulness:
Now a conscience-sniffing dog trained at a Padre Pio obedience school might be useful at times. Though they would have to be trained to differentiate between public and private sinners. The dogs howling when many modern hymns are sung could be a problem, that is if you could tell. Ushers with dogs that growl when you only throw in a dollar during the offertory could be beneficial. Attack dogs trained to only go after liturgical dancers would be useful in some parishes or ones that start to froth if you pick up a tambourine.
If you had to choose a breed of dog allowed at Mass what would it be? Sacred bloodhound? Papal Bulldog? Hound of Heaven would be nice, except for all the chasing. Would a Dalmatian wear a dalmatic. Priests with French Poodles (especially ones with clothes) should already be weeded out prior to seminary admission. Would their animals have to go to pet seminary? Sure obedience training would be required. In fact I can think of some priests that could also take a refresher in obedience training. None of these are good options, after all Jesus didn't tell Peter "Tend my sheepdogs."