Photo of Dr Doug Mader by Geraldine Diethelm, DVM
At the AIUM Annual Convention in San Diego, Debbie D’Agostini, Frank Tessler, and I shared the rather unique experience of scanning a 20-foot python—Joan Embery’s “Joyce.” Plenty of snake for all of us, Joyce placidly indulged our group with barely a writhe as the three of us took turns probing his ventral surface, peering at his 3-chambered heart and stretched-out abdominal organs. The experience of scanning such an exotic creature, not knowing exactly what to expect to see under his scales, resonated with that catch-in-the-throat wonder that accompanied my earliest experiences scanning humans.
For veterinarians Kevin Fitzgerald, DVM, and Doug Mader, DVM, scanning snakes and all manner of slippery, scaly patients is part of day-to-day practice. For years these two experts have used ultrasound to confirm pregnancies, evaluate hearts, identify tumors, and diagnose intestinal obstructions in a variety of reptile and other exotic patients. In fact, Dr Mader’s patient waiting room at the Marathon Veterinary Hospital in Marathon, Florida, must be a veritable Jurassic Park! Florida is home to more amphibian and reptile species than any other state in the United States, and Dr Mader welcomes most of them to his examining table. Besides caring for garden-variety snakes, turtles, and all kinds of lizards, Dr Mader sadly remembers a time several years ago when he was unable to save a fire eel with heart failure. “An ultrasound exam revealed ascites and possibly an enlarged heart. I suspected some form of cardiomyopathy, like DCM (dilated cardiomyopathy), but who knows for sure? We had nothing to compare it with.”
It’s humbling to contemplate the anatomic variety our veterinary ultrasound colleagues encounter as they scan patients of various species, many of which have not yet been fully described in the ultrasound literature.
And besides the challenge of anatomic mystery, there are the technical challenges of reptilian body habitus. With turtles, the sizes of inguinal openings that serve as scan windows are the issue. With snakes it’s the scales. When imaging snakes, an ideal method for reducing scale-induced artifacts is to submerge patients under water, a technique we chose not to attempt with 150-pound Joyce, opting instead for a generous application of gel.
Despite scales and shells, ultrasound plays an increasingly important role in reptile diagnostic imaging. According to Animal Planet luminary, “Emergency Vet” Kevin Fitzgerald, radiology is great for bones and certain organs, but it provides limited tissue information in reptiles. “Ultrasound is much more sensitive and revealing for tissue imaging. The benefit of ultrasound is its increased resolution of internal imagery when compared to radiology and its relative ease, safety, and noninvasive nature. It’s a powerful tool.” Hopefully powerful because Dr Fitzgerald reports ultrasound’s recent application for finding hemipenes in Komodo dragons. At up to 10 feet in length and more than 300 pounds, the clawed members of this ancient but endangered species have sharklike teeth and a nasty bite. Not the patient I want to go poking at looking for hemipenes.
Not much danger of that, really. According to Dr Fitzgerald, diagnostic radiology in veterinary medicine is performed almost entirely by trained veterinarians. Robert D. Pechman, DVM, executive director of the American College of Veterinary Radiology, confirms: “Although some are now employing and training sonographers to physically do the exam, veterinary ultrasound is mainly done by board-certified veterinary radiologists in this country. Each one has undergone 3 years of training in diagnostic imaging, including ultrasound, and has passed a rigorous examination on all these subject areas.”
But there is one ultrasound application that actually puts the transducer in the hands of lay individuals: animal breeding. According to Shawn Fisher of Fisher BioMedical Inc, among serious snake breeders the use of ultrasound to monitor follicle length and check for pregnancy
is “the standard.” The company markets equipment directly to breeders and offers technical instruction on its website and through personal face-to-face instruction. “Ultrasound maximizes results. It is also a lot of fun if you love snakes and breed them, even as an amateur.”
Love snakes? I have to admit to a certain fondness for Joyce, which is all the more reason for my questions and alarm. Could an amateur injure a snake while scanning? What about bioeffects? Is amateur scanning even legal? What are the moral issues? Where are the overlaps and differences between human and nonhuman ultrasound practice and philosophy? I welcome a dialogue on these issues and invite your comments to the Practice Matters blog. As for the legality, there seems only to be an issue if a lay person charges for services or makes a diagnosis, which would constitute practicing veterinary medicine without a license.
Whatever the future of “lay” ultrasound use may be, diagnostic veterinary sonography will certainly continue to improve the welfare of animals and fascinate us humans with its exploration of all manner of life forms. According to James E. Oosterhuis, DVM, principal veterinarian at San Diego’s Wild Animal Park, “Virtually all zoos have ultrasound units and will use them for diagnostic evaluation of snakes with medical problems.” And fire eels and turtles, as well as Komodo dragons with identity issues.
Posted by Kathi Borok 