Is a runny nose in a desert tortoise always a respiratory infection or could it be something else?
question from Karen Keller, Carson, California
A clear nasal discharge that is watery in nature (serous rhinitis) may be caused by numerous factors, but is
abnormal unless associated with recent water drinking. Reptiles lack a complete hard palate so there is a direct
communication between the oral and nasal cavities (choanae) that can allow a reflux of water back out the nostrils. I
have seen rhinitis associated with the stress of heavy intestinal parasite loads, which cleared up upon treatment with
a deworming agent. This can be diagnosed at a veterinary facility by microscopic examination of a fecal smear and
floatation of a stool sample. Bladder stones (urinary calculi or uroliths) can cause internal trauma to the lungs and
result in nasal drainage. Excess salivation and inhaled irritants such as pollen or foreign bodies can also lead to
Environmental conditions that are suboptimal, such as too damp or cold, can predispose chelonians to severe
contagious upper respiratory infection, which may progress to lower respiratory tract disease (pneumonia) with grave
consequences. Likewise, stress from over-crowding or malnutrition can predispose to upper respiratory infections, so
quality of the diet should be considered as well as over-all husbandry. For example, vitamin A deficiency
(hypovitaminosis A) causes thickening of the lining tissues of the eyelids and nose and may lead to secondary
bacterial infections. When a bacterial infection affects the nasal sinuses (sinusitis), the discharge tends to be
copious, opaque and thick (mucopurulent rhinitis) and may be one-sided (unilateral).
Prescribed antibiotics should be used to treat the rhinitis at this stage, preferably based on bacterial culture
and sensitivity test results. In chelonians of many species, but especially in the desert tortoise, the primary
infectious bacterial agent is Mycoplasma agassizii with common secondary gram-negative bacterial agents such as
Pasteurella species complicating the condition. There is a blood test for the Mycoplasma available at
the University of Florida, Gainesville that should be performed if infection is suspected as the cause of the
Dennis L. Fees, DVM
Arcadia Small Animal Hospital, Arcadia, CA
Tortuga Gazette 34(10): 9, October 1998
I frequently find a "pile" of white powder that I believe is coming
from my female desert tortoise. It appears to be passed in the urine. Is it anything to worry about?
question from Marty Haynes, California
Reptile owners frequently wonder about the "white powder" that is excreted by their pets. The material is uric acid
and its salts (urates). Be assured that it is normal for tortoises to pass it.
Uric acid is the end product of protein metabolism. It is cleared from the blood by the kidney into the bladder.
Uric acid and urates are relatively insoluble and crystallize into small chunks that are passed with the urine. The
amount of urate present in urine varies depending on diet and water intake. Urates are usually white to light yellow
On rare occasions, abnormalities may develop where urate crystals deposit in soft tissues forming the disease known
as gout. Another disease is cystic calculi or "bladder stones". These calculi are made up of uric acid salts similar
to those that are normally excreted in the urine. In this case the urates build up to form a large solid mass in the
bladder. Desert tortoises appear to have a high incidence of calculi. While the exact cause is not known, improper
nutrition and limited access to water have both been implicated.
Remember to provide water for them regularly.
Thomas J. Greek, MS, DVM
Greek & Associates Veterinary Hospital, Yorba Linda, CA