The mood in a Congressional office usually changes when staffers know a Member of Congress is around. But in Rep. Peter Welch’s office, a unique vibe goes into effect when the Vermont Democrat heads home to his district.

That’s when staffers know they have to keep a close eye on their food. And it’s probably wise to have a lint roller handy.

During recess and on the occasional Friday, Welch staffers are greeted by Moose, a 10-year-old yellow lab owned by Chief of Staff Bob Rogan.

Rogan adopted Moose in 2005 and brought him to Washington when Welch was elected and Rogan joined the staff. Moose is lovable, oh-so-cute and universally adored by staff, and he comes into the office on slower days. (He would likely get in the way when things get hectic.)

But when he does come to Capitol Hill, Moose has one goal in mind.

“The only Moose-related rule is to hide all food,— Welch spokesman Paul Heintz said. “The moment he arrives in the office, Moose generally does a full sweep of the area and vacuums up anything he finds that is at all edible. Trash cans have to be stashed out of reach, and lunches have to be watched closely.—

As President Harry Truman once quipped, “if you want a friend in Washington, get a dog.— On Capitol Hill, a place where true friends can be tough to find, there are a lot of dogs. And while some Congressional offices may favor cats or hamsters, let’s face it — dogs are Capitol Hill’s most adoring constituency.

[IMGCAP(1)]Sure, the first pets down the street at the White House get more attention. President Franklin D. Roosevelt’s beloved Scottish terrier, Fala, is immortalized alongside his master at the FDR Memorial, and the press keeps a close eye on Bo Obama, the first family’s Portuguese water dog.

But Bo never would have made it to 1600 Pennsylvania Ave. had Sen. Edward Kennedy (D-Mass.) not have fallen in love with his own water dogs, who frequently join him in the Senate.

Many other prominent Members have had a Congressional canine companion as well. Former Senate Majority Leader Bob Dole (R-Kan.) was often spotted with his miniature schnauzer, Leader.

These days, it’s Sen. Kent Conrad (D-N.D.) who is frequently seen walking his bichon frise, aptly named Dakota, or Rep. Linda Sánchez, who is joined on Capitol Hill by her beagle, Chavo.

“I think having a dog in the office can be a stress-reliever,— the California Democrat said. “Chavo makes sure he stops by to see everyone during the day … mostly whoever is eating.—

Plenty of other examples abound, with Members or their staff bringing lovable pups onto Capitol Hill to help ease the office tension, greet constituents or just provide a little unconditional love.

“Lawmakers are regular people,— said Wayne Pacelle, president and CEO of the Humane Society of the United States. “They have to have good morale and good experiences everyday, too. Pets bring us enormous happiness.—

The Humane Society (the source of many a workplace dog) published a book offering employers tips for keeping pets in the office, “Dogs at Work: A Practical Guide to Creating Dog-Friendly Workplaces.—

Studies show that pets offer huge benefits, including a more creative work environment, improved morale and less truancy — in part because people don’t have to rush home and let the dog out, Pacelle said.

For Conrad, having Dakota in the office seems to lower stress and build staff camaraderie. The Senator and his wife rescued Dakota in March and felt it would be unfair to leave the dog at home alone all day, given Conrad’s lengthy work days.

“Dakota was in bad shape when the Senator first adopted him but is now doing very well and is an extremely loyal companion,— spokesman Sean Neary said. “In North Dakota, it’s not uncommon to have your dog follow along during the day’s activities on the family farm or ranch.—

Like Conrad, Rep. Ed Whitfield (R-Ky.) often brings his Parson Russell terrier, Nigel, to the office on days when he knows he’ll be working late.

“Nigel will usually come in, circle through the office and check up on everyone before settling into the Congressman’s office,— spokeswoman Kristin Walker said.

Whitfield oversees Nigel’s care, taking him on walks and feeding him, but most staffers enjoy having the pooch around, Walker said. Staffers even keep a sign with a picture of Nigel on the office door to let visitors know when the pup is around.

Not all Members are able have their own pets. Rep. Ken Calvert (R) wanted to get a dog but felt having to travel back to his Southern California district so often would make it hard to properly take care of one.

So Rebecca Rudman, Calvert’s communications director, took up the task. After searching local breeders, she fell in love with a female miniature dachshund that she named Cali, and these days, the pooch is an office regular.

Cali’s main spot is a doggie-approved area next to Rudman’s cubicle (complete with plenty of doggie toys), but she also regularly takes naps on staffers’ laps. “She knows who will pamper her and who won’t,— Rudman said.

And although Rudman serves as Cali’s main master, Calvert does have a way with her. “When she hears his voice, she’ll be dead asleep and she’ll get up and run to him,— Rudman said.

It really doesn’t matter who owns an office pet — staffers tend to come together to take care of the animals, creating a sense of camaraderie, Pacelle said.

In Moose’s case, Rogan does most of the dirty work, while “other staffers will occasionally take on the onerous tasks of riling him up, feeding him under the table and scratching his belly,— Heintz said.

Sánchez has found it difficult to find someone to regularly walk Chavo. It’s become a group effort, with the Congresswoman walking him between votes, or staffers or interns taking a break to bring him outside for a few minutes.

Chavo certainly is the office star. In fact, the pup — whom Sánchez rescued from a Pennsylvania shelter in 2005 — arguably attracts more attention than his master and even has been featured in National Journal and the Washington Post.

“Before you know it, he might need his own press secretary,— Sánchez joked.

Perhaps all that fame has gone to his head, because Chavo occasionally finds himself in trouble. For example, when Chavo notices someone sitting in his favorite spot on a couch in Sánchez’s office, he’s been known to squeeze behind the person and nudge her out of the way.

But Chavo has some competition on the cuteness front. Sánchez’s infant son, Joaquin, is a new fixture in the office — and the pooch is a bit jealous of all the attention.

“He’s no longer the cutest thing in the room,— Sánchez said. “But I know that he will become just as loyal to Joaquin as he is to me.—