What was supposed to be a straightforward rematch of Sunny's Halo, Desert Wine and Marfa in the Preakness has become a battle of the ringworm vs. the bleeder vs. the cracked hoof. The 80,000 people at Pimlico on Saturday may want to consult veterinary manuals and law journals along with their copies of the Daily Racing Form.

Although the physical condition of the contestants is an important factor in any horse race it has rarely been so central--or so ambiguous--as it is in this 108th Preakness that goes off at 5:38 p.m. (WJLA-TV-7).

While Sunny's Halo has been in the hands of a battery of veterinarians because of a skin rash, Desert Wine was in the hands of a battery of lawyers today. After the colt was denied permission to use the antibleeding drug Lasix because he didn't qualify for it under Maryland's stringent rules, his owners went to the Circuit Court in Baltimore and got the ruling of the state veterinarian overturned.

The medication is important to Desert Wine. He gave the one bad performance of his career when he bled in the Santa Anita Derby, but when he was treated with Lasix, he finished second in the Kentucky Derby.

The ruling also allows Marfa to use Lasix in the race. Marfa's physical problem appeared to be more serious than those of Sunny's Halo and Desert Wine. The gray colt, who finished fifth as the favorite in Kentucky, cracked his left front hoof during a swift workout on Wednesday, and trainer Wayne Lukas had to summon a blacksmith from California to repair the damage. He covered the crack with an acrylic patch, held in place by piano wire and 13 screws.

"It's a matter of major concern," Lukas said. "We have enough worries without it. But I'm hopeful that the patch will hold." Marfa did not show any noticeable signs of distress as he galloped this morning.

Despite all the publicity about the skin rash that has been plaguing Sunny's Halo, his condition may give him the edge he needs to capture the second leg of the Triple Crown.

Trainer David Cross has fretted constantly about the skin disease, worrying mostly that it would get into his colt's system. He also had to worry that the antibiotics used to treat it might weaken Sunny's Halo.

"It's still a touch-and-go situation," he said today. But the Kentucky Derby winner has trained superbly this week, impressing everyone who has seen him on the track, and unless his condition takes a sudden turn for the worse he will come into the Preakness fit, fresh and sharp.

Sunny's Halo, Marfa and Desert Wine will attract most of the betting on Saturday, with Sunny's Halo expected to be the favorite at 4 to 5 or less. But there are a number of others in the 13-horse lineup with the credentials to score an upset: Play Fellow, Deputed Testamony, Paris Prince, Current Hope and Flag Admiral.

If the health of the principals does not determine the outcome of the Preakness, the tactics of the riders may. At Churchill Downs, Sunny's Halo and Desert Wine had everything their own way, stalking a slow early pace, avoiding the heavy traffic in the 20-horse field, never having to exert themselves seriously until the final turn.

The Preakness will be run differently. There is a speedster in the field, Bet Big--who in keeping with the theme of the race has been suffering from two shin splits. He ought to set an honest pace. And Desert Wine isn't going to wait to challenge Sunny's Halo as long as he did in Kentucky. "He's a free-running horse," jockey Chris McCarron said, "and we're going to let him run his race. If we try to take him back--especially on this track--we'd only hurt him."

The faster pace ought to give the stretch-runners who failed in the Derby a much better chance today. Marfa, Play Fellow and Paris Prince all made decent moves on the turn at Churchill Down, but the horses in front of them were too strong to catch.

With a forecast of rain for Saturday, the condition of the Pimlico racing strip could also affect the outcome of the Preakness. Today there were some signs of the rail-favoring bias that carried Aloma's Ruler to an upset victory here last year.

If the track is wet, none of the favorites is likely to be hindered by it, but the chances of Play Fellow would be helped. He won the Blue Grass Stakes at Keeneland in the slop, and when trainer Harvey Vanier surveyed the wet conditions this morning, he said, "I'd like to run right now."

Most of his rivals, tending to their horses' assorted ailments, are in no such hurry.