Upper Respiratory Tract Disease, often abbreviated as URTD or URP, is a common condition in Sonoran desert tortoises.  "Upper respiratory tract disease" refers to an infection of the nose, nasal sinuses, and trachea (wind pipe)  It typically starts as a clear nasal discharge that may persist for weeks.  Sometimes the discharge dries around the nose and forms a white crust.  Some tortoises may have bubbles blow out their nose and some may make whistling sounds, clicks, or even gurgles.  A badly affected tortoise may have its mouth slightly open because mucus secretions have blocked both of its nostrils.  Over time, an ill tortoise may become lethargic and stop eating.  In some tortoises, the disease can erode away the nasal sinuses and create a chronic infection known as sinusitis.

URTD is most commonly caused by a microscopic organism known as Mycoplasma agassizii.  This mycoplasma colonizes the cells lining the nasal passages.  Tortoises pass the infection by living in close contact with each other.  If you have a healthy tortoise that has never had a runny nose, be very careful about introducing new tortoises to your home!

There are antibiotics that are very effective at treating the disease but there is no antibiotic known that will completely clear the mycoplasma out of the tortoise's body.  Once a tortoise contracts mycoplasma, it is a carrier for life.  "Runny noses" may flare up following any stressful situation such as a move to a new home or hibernation.

As a veterinary student, Dr. Jay Johnson was part of the research team that determined the best dose of the antibiotic clarithromycin for Sonoran desert tortoises.  This is one of the few studies done that scientifically documents what happens to an antibiotic in a tortoise's body and was a major advance in developing an effective home treatment for mycoplasmosis.  Dr. Johnson has also studied the impact of the disease on wild populations of tortoises which has helped developed his approach to treating sick pet tortoises.

Runny noses sometimes happen for other reasons such as allergies, foreign objects in the nose or mouth, or other infections such as viruses, bacteria, and fungi.  Occasionally, a nasal discharge is a harbinger of a much more serious respiratory infection of the bronchi and lungs known as pneumonia.  For this reason, it is essential that you set up an appointment to have your tortoise examined whenever it has a nasal discharge that lasts for more than a few days.  It is much easier to treat a tortoise while it is still active and eating than to treat one that has been sick long enough to lose its appetite and energy!