Archived News

Ultrasound lets vets take a close look at snake eye health

July 29, 2005

Ophthalmology PracticeUsing a leading-edge form of ultrasound technology, Steven Hollingsworth, chief of the Ophthalmology Service, led a veterinary team that spent Saturday, July 16 making the first high-frequency ultrasound studies of the eyes of 12 live snakes.

The study's goal is to improve snake medical care by producing the first detailed baseline information about the structure of healthy snake eyes.


Dr. Hollingsworth, ophthalmology resident Dr. Brad Holmberg, and avian/exotics resident Dr. Anneliese Strunk first evaluated the snakes for signs of their overall health and then examined their eyes. Fourth-year students Leann Sickafoose and Alicia Oakley also participated in the study.

Operating at a very high frequency of 50 megahertz (most units in human clinics operate in the 1-megahertz to 7-megahertz range), the state-of-the-art ultrasound device allowed researchers to make very precise measurements of the dimensions and shape of the snakes' eye structures, such as the cornea and iris.

Snakes do not have eyelids like those in dogs and cats. Instead they have a protective membrane, called a spectacle, over each eye. Tears moisten the area between eyeball and spectacle, or subspectacular space. Hollingsworth, Strunk and Holmberg paid particular interest to the measurement of the subspectacular space, which is unique to snakes and a few types of lizards.

When the snake periodically sheds its skin, the spectacle is shed, too. However, if the spectacle does not shed completely, or if the subspectacular space or the tear duct is affected by disease, the snake's eye can become painful and lose some or all of its function.

Few resources exist for veterinarians needing information about the anatomy of snakes' eyes. By improving understanding of the anatomy of a healthy snake's head and eyes, the study results should help veterinarians provide better care for these exotic pets.


PythonThe animals included ball pythons and two California native species, the California king snake and the gopher snake. Their visit to the Veterinary Medical Teaching Hospital was made possible by arrangement with the Northern California Herpetological Society and Dr. Sue Solomon, professor emeritus in the Department of Management Information Science at California State University, Sacramento.

Dr. Solomon, a snake enthusiast, has spent countless hours rescuing, rehabilitating and finding homes for snakes and other reptiles. Through her long-time association with the school, many snakes have been brought to the teaching hospital for examination or treatment. Those cases have helped numerous veterinary students learn more about exotic pet medicine. Dr. Solomon has also supported clinical research into reptilian disease and treatments, including safe methods of anesthetizing animals for treatment. In recognition of her long-term commitment to developing important advances in animal health and well-being, Dr. Solomon has received the school's 2005 El Blanco Award.

The Companion Avian and Exotic Pets Service and the Ophthalmology Service of the Veterinary Medical Teaching Hospital provide advanced care and treatment for snakes and other animals. If your animal is injured or you suspect an illness, please consult your veterinarian.

For more information about specialized veterinary services at the School of Veterinary Medicine, please visit the Web site of the Veterinary Medical Teaching Hospital. For an appointment at the Small Animal Clinic, you may ask your veterinarian for a referral, or you may call the clinic, (530) 752-1393.

To learn how you can assist veterinary scholars who are developing new knowledge about animal health, please call our Development Office at (530) 752-7024 or visit