Horses with diaphragmatic tears (also called rents) are given a relatively poor prognosis to make a full recovery, but the condition is not a death sentence, according to the results of a recent retrospective study. Alfredo E. Romero, DVM, of Syracuse Equine Veterinary Specialists in Manilus, N.Y., and colleagues found that the overall survival rate for horses presented with a diaphragmatic rent was 23%, and surgery to correct the rent produced only a 46% survival rate.

The diaphragm is an essential organ in the body that controls the horse’s breathing. Diaphragmatic tears are "seldom diagnosed," said Romero in his study, and they are generally associated with trauma or congenital defects (i.e., there’s little owners can do to prevent the occurrence of rents). When diagnosed, horses often present with signs of colic.

"Vague clinical signs are the hallmark of diaphragmatic herniation," he continued. "These include colic most often, but can also include tachypnea (increased respiratory rate, decreased respiratory volume). Additionally, tachycardia (increased heart rate) can also be observed and is most often associated with pain in general."

In the study Romero wrote that there "have been no substantial surveys of diaphragmatic rents or defects seen at referral hospitals," and most of the studies in the past have examined no more than six cases. For the current study, Romero and his team examined the records of 31 horses that were diagnosed with a diaphragmatic rent between January 2001 and June 2006 at Hagyard Equine Medical Center in Lexington, Ky., or the University of California, Davis, Veterinary Medical Teaching Hospital