Parkinson said that, in most cases, the benefits of having a catheter in place—allowing the veterinarian to give fluids, use more effective medications, reduce the need for painful injections, and give rapid venous access in emergencies—far outweigh the risks. | Photo: Anne M. Eberhart/The Horse

Veterinarians regularly use catheters to deliver medications, fluids, and more, especially in hospitalized horses. While this tactic is helpful in most cases—reducing the number of needle sticks the horse must endure—in rare cases air can leak into the bloodstream. This phenomenon, called a venous air embolism, can have serious—even deadly—complications.

“This is a problem that we have known about for a long time, but we are generally reluctant to talk about it due to the difficulty in proving what has happened,” said Nicholas Parkinson, MA, MS, VetMB, Cert. EM (Int. Med.), Dipl. ACVIM, MRCVS, a veterinary clinical lecturer at the University of Edinburgh Royal (Dick) School of Veterinary Studies, in Scotland. “There is also the worry that a veterinarian might be perceived as being ‘at fault’ should this complication occur. Even when the catheter had been placed by experienced qualified veterinarians, it can still occur.”

Parkinson recently worked with colleagues to describe the surrounding circumstances, clinical signs, treatment, progression, and outcome of venous air embolism in 32 hospitalized horses