Belmont winner Rags to Riches back in form after bone scan

On June 9, 2007, Rags to Riches nosed out Preakness winner Curlin in a courageous duel down the stretch to become the first filly in 102 years to win the Belmont Stakes, and only the third filly to do so in its 139-year history.

In top form: Jockey Garrett Gomez rides Rags to Riches to an easy victory in the 133rd Kentucky Oaks race at Churchill Downs in May. The filly later won the Belmont Stakes, then underwent a high-tech full examination that included a bone scan before being pronounced fit to run again.

Sired by Belmont Stakes winner A.P. Indy and half-sister to 2006 Belmont Stakes winner Jazil, Rags to Riches has five wins in five starts in 2007 and earnings of $1,292,528.

But just six weeks after Belmont, Rags to Riches spiked a fever while stabled at Belmont Park on New York's Long Island and was quickly declared out of the July 21 Coaching Club American Oaks race.

On Sunday morning, July 22, Rags to Riches was to breeze five furlongs but, after just one-sixteenth mile into the workout under exercise rider Lauren Robson, she was pulled up abruptly. Though the 3-year-old filly reportedly showed no signs of injury, Robson felt something was amiss and took the horse back to the barn.

Whether Rags to Riches stepped on something or just took a bad step is unknown.

Dr. Steve Allday, DVM, was called to give the horse a physical exam the next morning. While finding her generally sound and in good condition, Allday believed it prudent to recommend she be taken to the University of Pennsylvania's New Bolton Center for a complete physical, including a bone scan.

"She's here for elective nuclear scintigraphy, a bone scan," said Ben Martin, VMD, DACVS, associate professor of sports medicine at New Bolton.

'Gamma camera' view: Bone scan picks up the radioactivity from the tracer substance and notes where the tracer is absorbed (a "hot" spot) or not absorbed ("cold" spot) as darker and lighter images.

Nuclear scintigraphy is an effective methodology for horses where lameness is minimally detectable, cannot be localized or remains uncertain after a common lameness exam and radiographs that determine bone damage, especially to limbs and pelvis.

A bone scan involves intravenous injection of a radioactive tracer substance, Technectium 99m, bound to a phosphate compound, 99mTc-MDP, "the bone-seeking agent," or tracer. The tracer travels first through the blood (phase 1 or vascular phase), which may show impaired circulation in a limb; then to the soft tissues (phase 2), which may show an area of inflammation, possibly a problem with the suspensories, a tendon; and finally to the bone, where a concentration of material indicates increased bone metabolism/increased bone remodeling (i.e., possible fracture, stress fracture or infection).

The vascular phase is noted immediately post-injection, the soft-tissue phase within 30 minutes post-injection and the bone phase within two to three hours. Areas that particularly absorb the material are known as "hot spots," as opposed to those that do not, dubbed "cold spots."

The "gamma camera" takes bone images, picks up the radioactivity and notes these hot and cold areas as darker and lighter aspects of the computer-generated images.

That completed, other modalities, including "blocking," radiographs, ultrasound and/or MRI, can be used to further diagnose the potential injury site.

"Particularly in the Thoroughbred racehorse, catastrophic injury is a potential," says Martin. Thoroughbreds can get stress fractures in their shins, tibia or humerus. "The horses may be quite lame one day and the next they're fine, so one of the big advantages of using the bone scan is that you can figure that out, without putting the horse or the rider at risk," Martin explains.

'We're looking for America'

'With the bone scan, as opposed to MRI, one can check the whole leg, back or pelvis, while an MRI only can check from the knee down. Things happen in the rest of the horse's body that can't be accessed with MRI, one of the key advantages of nuclear scintigraphy.

"Basically, like Columbus was looking for America, we're looking for America in the horse's body essentially," Martin says. "We're looking for that dark spot or spots that may be clinically applicable."

Horses also have hot spots that are not clinically meaningful, so part of the clinician's job is to figure out what's real and what's artifact.

"It's not a big deal for someone to refer a horse for scintigraphy," says Martin. The next step for Rags to Riches was further imaging that might locate an area that doctors might want to radiograph or look at with ultrasound, or perhaps an MRI.

"If it's her foot, you might want to look at it with an MRI, if you don't see anything on radiograph," explains Martin. "It's kind of a stepwise search."

If a horse is lame and has never been "blocked," one would proceed forward and start blocking. It often occurs that horses come to New Bolton fairly lame, get a bone scan with basically poor results, then must go back to the sort of basics performed 10 to 20 years ago — blocking the horse see where, or if, it is lame.

A decision to make

In the case of Rags to Riches, if the horse looked fine and the bone scan was totally negative, then her owners would have to decide what they wanted to do.

"I could say physically she's perfect and she's sound and she's happy, etc. Then they'd need to decide, do they want to keep training and racing her, do they want to give her the rest of the year off and run her next year or send her to the breeding shed? Those are all fairly common choices," Martin explains.

On the other hand, if they found something they could address, they would form a plan to do so. The three most likely outcomes are (A) she goes back to the racetrack, (B) she gets retired or (C) she has a period of rehabbing.

"Even though she supposedly didn't show any obvious signs of lameness and her veterinary exam at Belmont Park was fine, I never say it's good. I always say it's guarded, because you just never know," says Martin. "They're so fragile. Hopefully she's healthy and she'll be running at Saratoga (in the Alabama) in a few weeks, knock on wood."

On July 28, Rags to Riches' trainer, Todd Pletcher, said Dr. Paul Thorpe, DVM, of Lexington, Ky., attending veterinarian for owners Michael Tabor and Derrick Smith, was returning from a prior commitment in Ireland and would also inspect the filly.

Everyone had been waiting on Thorpe's input. "He's going to process all the information — the scan results, the X-ray, the complete physical workup that they did on her," said Pletcher. "He'll examine the filly himself and hopefully give us a clean bill of health, and we can move forward."

It was decided after the complete exam at New Bolton Center that Rags to Riches could resume training. On July 31, the horse had her final gallop at Belmont Park prior to shipping on to Saratoga to resume training.

According to Pletcher's team, "she looked great, was doing well," and was vanned to the upstate racetrack to get her back in physical condition. Thorpe had a chance to examine her again there. "She looks fine," he said.

The daughter of A.P. Indy galloped 1.37-mile at Saratoga on Aug. 2 and had an easy half-mile breeze in 49.86 on Aug. 5.

Apparently the hiccup on July 22 was nothing more than that.

The care given by Martin's staff and the technology of nuclear scintigraphy allowed for a detailed look at her musculoskeletal integrity.

At press time, the horse was set to race against older fillies and mares Sept. 8 in the Grade 1 Ruffian for F&M 3-and-Up at a mile and a sixteenth. Pletcher's ultimate goal is to run the horse in the Breeder's Cup in October, at Monmouth Park, N.J.

Ed Kane is a Seattle author, researcher and consultant in animal nutrition, physiology and veterinary medicine, with a background in horses, pets and livestock.