Lola, a 13-year-old Thoroughbred/Quarter Horse mare, delivered healthy twin foals Tuesday, a rare occurrence among horses. (Submitted photo)

"Twin foals that survive are very, very rare ... I think it is about a one in 10,000 chance that both will survive," said Dr. Monty McInturff, the veterinarian from the Tennessee Equine Hospital who delivered the twins. "I have seen one set of twins prior to this to be born healthy and survive."

The birth of twin horses is rare because a horse's uterus cannot normally support two babies. When twin pregnancies are discovered early, they are often aborted to prevent complications with pregnancy and birthing.

McInturff and horse owners Christy Swaze of Shelbyville and her daughter, Evelyn Swaze of Murfreesboro, were completely taken by surprise when Lola, a 13-year-old Thoroughbred/Quarter Horse mare, gave birth to the twins Tuesday.

"After Lola was initially pregnancy-checked at a local breeding facility I assumed everything was normal," said Evelyn Swaze, a trainer at Hunters Court Stables in Murfreesboro. "I didn't have any other ultrasounds done; I just let nature take its course."

McInturff said that while he has delivered one set of healthy twins in the past, the foals were not equal in terms of size and leg confirmation. Lola's twins are very similar in both size and confirmation.

Also, in Lola's case, the twins -- one filly and one colt -- were carried to full term, which is extremely rare when a mare is carrying twins.

"The big surprise is that she carried them to term," he said. "She was one day off from her due date. Usually, when twins are born, they are six weeks early."

The Swazes are fully aware of the blessing bestowed upon them with the birth of healthy, equally-sized foals carried to full term. They are very excited about the future.

Over the next several years Evelyn will train Lola's babies to become hunter/jumper show horses and when the time is right, they'll probably be sold.

The final product is expected to be pretty special, according to Evelyn.

"Lola's official name is Guilt Free and she was bred with a popular Welsh pony named Clovercroft's Abba Adonia. We have decided to name the filly Clovercroft Caught Red Handed and the colt will be named Clovercroft Not Guilty."

When Lola and the twins leave the Franklin-based veterinarian clinic this weekend, they'll make their home at Christy Swaze's farm in Shelbyville. This was the Swaze's first time breeding a mare, so both are very much looking forward to the months ahead.

When they are weaned, in about four months, Evelyn will take the twins to Murfreesboro and begin the training process.

"I want to start training them early," said Evelyn. "I have high expectations."