Things looked grim for the Navy goat.

Nauseated and laboring to breathe, he was rushed by his handlers from Annapolis, Md., to the New Bolton Center of the University of Pennsylvania, the nearest 24-hour large-animal hospital.

Blood tests showed abnormalities in his electrolytes and a high level of acidity. It appeared that Bill - Bill 36, to be exact - might have eaten an azalea bush, toxic to goats.

Holly Roessner, an intern on duty in the emergency room that November night, inserted a tube down Bill's throat and into his rumen, the largest of his four stomachs. Then she administered medicine to absorb the toxins. New blood tests showed it was working, and an addition of a painkiller the next morning had Bill back on all fours.

"He looked great," Roessner said.

On Saturday, healed and healthy, Bill 36 will trot to his place on the sideline and carry out his duty - to bring good luck to the midshipmen when the 116th Army-Navy game kicks off at Lincoln Financial Field.

Credit Penn Vet with saving the day.

Or at least, with curing an ailing goat who twice this fall required treatment at New Bolton - and whose successful care ensured his ongoing role in a tradition that dates to the 1890s.

"He's doing great now," said Naval Academy spokeswoman Jennifer Erickson.

Bill 36 and his twin brother, Bill 35, are 21-month-old purebred Angoras, weighing about 75 pounds and donated to the academy by a Texas rancher. This football season, they began formal mascot training, which includes becoming acclimated to crowds, children, and ceremonial cannon fire.

They'll replace Bill 33 and Bill 34, who are nearing retirement. All four will be accompanied to Saturday's game by a group of a dozen midshipmen known as Team Bill.

The Navy goats, long the target of kidnappers from rival Army, live at an undisclosed location in the Annapolis area, tended by caretakers whose identities are undisclosed.

"It's the Navy's best-kept secret," Erickson said.

To seafarers, it makes perfect sense that Navy has a goat as a mascot. Goats have been brought aboard ships for centuries.

At sea, goats provided crews with fresh dairy, meat, and leather, according to research by the Naval Academy and the U.S. Naval Institute, a nonprofit that studies sea power.

Goats offered advantages over cows - they were smaller and needed less to eat. And they were footsure on rough seas. A storm could turn a cow into a 1,000-pound battering ram, but no one worried about getting bumped by a goat.

Goats dined on scraps and leftovers, serving in effect as the ship garbage disposal, the institute wrote. They offered an added plus if the ship flooded or sank: Goats can swim.

As food storage improved in the 19th century, shipboard goats became more mascots than meals. Yet the story of how a goat became the academy good-luck charm is disputed.

An inscription by the 1957 bronze goat statue at the academy traces the origin to 1890: A group of midshipmen snatched a goat as they marched to West Point for the first game, won by Navy.

Another version holds that after the death at sea of a favorite goat, two ensigns were assigned to take the goatskin to a taxidermist. When their ship docked in Baltimore, they headed to Annapolis to see a football game. At halftime, one ensign wrapped himself in the skin and ran through the stadium, to cheers.

Navy won - and the departed goat got the credit.

A live goat made its mascot debut at the Army-Navy game in 1893. The USS New York docked near Annapolis, and the ship mascot, a goat named El Cid, was brought to a 6-3 Navy victory. Another goat from the same ship was taken to the Army-Navy game in 1900, adorned with a blanket emblazoned with "Navy."

Navy won - and tradition solidified.

Over time, all but three goats have been named Bill. At least one was discharged from duty after football losses. Two died of accidental poisoning after weed killer was sprayed too close to their pens.

The medical travails of Bill 36 began on a September evening, when a dozen Naval Academy leaders gathered to meet the two new mascots. Caregivers realized that Bill 36 was in trouble, straining to urinate. They phoned a veterinarian, who recommending taking the goat to an animal hospital.

At Penn Vet, Dr. Holly Stewart thought the goat had "obstructive urolithiasis," that is, mineral stones blocking his urethra.

An ultrasound and rectal exam appeared to confirm the diagnosis. Emergency surgery was the only option.

Once the stones were removed, Bill 36 was able to urinate. Medications aided in what doctors called a perfect recovery.

Three weeks later, both Bills were castrated, common for young male goats. They're now wethers.

But Bill 36's health problems weren't over.

In early November, he began drooling and vomiting, then struggled to breathe.

Bill was met at the New Bolton center by Roessner, who was supervised by Louise Southwood, a surgeon and emergency-care specialist.

It wasn't Roessner's first goat. The hospital sees quite a few, along with horses, cows, and the occasional zebra or camel.

Roessner said she felt no added pressure in treating this particular goat, despite his prestige.

"We try to uphold the best medical care for all of our patients," she said. "We treat them all as if they were the Navy goat."