Sen. Edward Kennedy arrived on Capitol Hill Monday with his wife and two dogs — the first time the Massachusetts Democrat has been at work since July after he was diagnosed a month earlier with a brain tumor.

Kennedy said he's feeling great and wants to work on an economic stimulus proposal before trying to expand health care for all Americans through legislation next year. He was in town for the start of the lame duck session of Congress, expected to last about a week before finishing up for the year.

In a statement, Kennedy said he will "continue to lay the ground work for early action by Congress on health reform when President Obama takes office in January. We've been making real progress in our discussions about a consensus approach and I'm optimistic we'll succeed."

He added that he is "grateful for the prayers and good wishes I’ve received over the past several months. They have certainly lifted my spirits, as has the election of Barack Obama as our 44th president."

Kennedy was greeted by cheers as he entered the main hallway of his Senate office building. He joked that his two dogs, Splash and Sunny, were behaving well and vying to be top dog.

Kennedy, 76, was last on Capitol Hill for a July 9 vote on a Medicare bill that passed despite Bush administration opposition. That was his sole return to Congress following surgery on June 2 for a malignant brain tumor that usually gives patients only a few years survival.

Kennedy delivered a speech at the Democratic National Convention in Denver in August. He was an early supporter of Obama.

FOX News' Heidi Noonan contributed to this report.