Over The Limit? Equine Ultrasounds Can Cause Vets To Test Positive For Alcohol by Paulick Report Staff|03.17.2023|6:41pm Veterinarians may get a false positive in a breath alcohol test after administering an abdominal ultrasound, a study by Dr. Valentina Vitale out of the University of Pisa reports. The false positives are from inhaling fumes of the rubbing alcohol used to saturate the area receiving the ultrasound. Similar false positives have been found from using alcohol-based mouthwashes or from inhaling alcohol vapors from hand sanitizers. Practitioners performing ultrasounds are often exposed to the alcohol vapors for significantly longer than others are exposed to hand sanitizer fumes or mouth washes, Vitale explained. Though ultrasounds can vary in duration, in some cases, like colic, they can be repeated multiple times. If a veterinarian who performed an ultrasound (or multiple) is pulled over by police and given a breathalyzer, he or she may have a false positive test. To test the theory that a positive breath test would be found after an ultrasound was performed, Vitale and a team of researchers had six people perform 36 ultrasounds (six each) on the same 20-year-old Standardbred mare owned by the University of Pisa in Italy. Each person poured the ethanol solution from a jar or sprayed it and examined the horse for 10, 30 and 60 minutes. A breathalyzer test was given immediately after the exam and then at 5-minute intervals until a negative test occurred. The tests showed that alcohol was detectable on the breath of the operators for up to 60 minutes after the procedure, with a median of 7.5 minutes. “Positive” tests – those that are greater than 0.05 percent, which is the legal limit to drive – were detected for up to 35 minutes after the conclusion of the exam. Positive tests that were within the legal limit to drive (0.018 to 0.05 percent) were detected for up to 55 minutes after the exam, with a median time of 5 minutes. The amount of alcohol used also significantly affects the detectable level of alcohol. The operators who used more than 33 fluid ounces of ethanol tested positive for longer. In 83 percent of cases, a positive result occurred immediately after the ultrasound, no matter how much ethanol was used. All participants tested positive several times during the experiment. While those performing the ultrasounds may not have blood alcohol levels that are raised as much as when drinking alcohol, there is an increase in blood alcohol levels following exposure. Though this may not trigger impairment commonly associated with alcohol, it may make operators more reactive to alcohol cues and encourage drinking behavior. The team recommends that practitioners wait at least 35 minutes after an abdominal ultrasound before driving. Read more at HorseTalk.