06/13/2002 12:00AM

Modern career mares: Pregnant and racing


LEXINGTON, Ky. - When leading female earner Spain heads for the starting gate Saturday in Churchill's Grade 2 Fleur de Lis, she will be carrying a little extra weight. The 5-year-old mare is one month pregnant to Storm Cat but is continuing her racing career, apparently with little need for change in her care.

"The examining vet just said to carry on," Spain's trainer, D. Wayne Lukas, said Thursday morning. "We're doing everything the same."

It's unusual but not unheard of for pregnant mares to campaign. In fact, there's another top-class, in-foal runner training at Churchill now: Caressing, 2000's champion 2-year-old filly, is carrying a foal by Fusaichi Pegasus from an April 21 breeding date.

In 1992, multiple graded stakes winner Fit for a Queen competed successfully while in foal. She won her last start, the Grade 2 Turfway Breeders' Cup Stakes, on Sept. 20, before retiring to have her first foal, a Gulch colt named Ground Swell.

Although a pregnant runner is something of a curiosity, they generally don't require much in the way of special management, trainers and veterinarians say.

Conventional wisdom holds that in-foal mares can race for several months into their pregnancies, but veterinarians caution trainers to be careful with medicating pregnant mares and warn that steroids like Azium, if given in substantial doses, can induce abortion in later stages of pregnancy.

"The first trimester is where you get most of the development of the foal," said Dr. Jerry Johnson, "so you have to be careful of stressful situations and medication. They'll get tired easier and they're essentially feeding another mouth, so you'd probably want to increase the mare's caloric intake as the pregnancy goes along."

"When these mares go back to the track, you keep them on a balanced ration," said Dr. Scott Kendall, Caressing's attending vet. "I don't think racing in the first three months is hazardous. I tend to stop racing them in the fourth or fifth month of gestation. For one thing, they're more susceptible to exposure to infectious diseases after about five months, so they're probably better off away from the racetrack and in a more closed-herd environment."

Other than minor adjustments to feed amounts and judicious medication use, there's little else to do but monitor dam and foal.

"We've scheduled ultrasounds for 14, 28, 36, 45, 60, and 90 days," said Caressing's owner, Carl Pollard. "We just did the 45-day scan on Monday or Tuesday, and she was fine.

"Honestly, I was a little concerned about it, but the vets said they couldn't tell us why not to do it, and other people had done it before us. She actually seems to be a little calmer once she got in foal. She was a handful before that."

Lukas says that Spain's pregnancy also has had no ill effects on her training.

"She actually seems to be thriving on being pregnant," he said.

Blaming the caterpillars

The University of Kentucky released the results of a study Wednesday that links exposure to eastern tent caterpillars and early fetal loss in pregnant mares.

In the study headed by UK entomologist Dr. Bruce Webb and Gluck Equine Research Center scientist Dr. Karen McDowell, three of eight mares exposed to caterpillars during a six-hour pasture turnout aborted their early fetuses. None of the eight mares exposed only to caterpillar excrement, or frass, aborted; one of eight mares aborted in the control group, which had no intentional exposure to caterpillars or frass.

The UK announcement was the second this week to blame the caterpillars for last year's wave of mare reproductive loss syndrome. Earlier this week results were released of a study at Lexington's Rood and Riddle equine hospital. That study induced abortion in each of five mares fed a "cocktail" of 50 grams of crushed caterpillars and 50 milliliters of water; mares fed frass and water or only water did not abort.

"Now we have to figure out how the caterpillars do it," said Dr. Nancy Cox, UK's associate dean for research. "We'll be looking at all manners of exposure and for what the toxic compounds are in the caterpillar."

Dr. Bill Bernard, one of the Rood and Riddle study's chief investigators, said his team is planning a small-scale pilot study within the next several weeks to examine the caterpillar.

"Several questions arise," Bernard said. "Can just two or three caterpillars cause the problem? Do they have to be fresh? Do they release a chemical on the grass? Is the caterpillar itself toxic?

"We don't know yet exactly how it happens, but I really think that if we get rid of the caterpillars, we'll get rid of the problem."

Etc. . . .

The Ocala Breeders' Sales Co. will hold under tack shows for its June 18-19 summer juvenile sale on Saturday, June 15, and Sunday, June 16. Sessions will start earlier than usual, at 8 a.m. . . . Fasig-Tipton has catalogued 228 yearlings for its selected yearling sale at Saratoga from Aug. 6-8. The catalog, which includes 146 colts and 82 fillies, will be available at all Fasig-Tipton offices starting June 24.

- additional reporting by Marty McGee