Upper Respiratory Tract Infections

     Signs of URTD in tortoises may include runny nose, watery eyes, swollen or sealed eyelids, and a slight reddening in the inner corner of the eye. Severely ill tortoises may be lethargic, barely able to move despite what is going on around them, and basket when it's too cold.

This is a condition that most owners of North American tortoises are familiar, whether personally or through other reptile owners. Typically, the syndrome manifests as nasal discharge, conjunctivitis, oral lesions, or more serious respiratory disease. The only confirmed bacteria associated as causative agents are Mycoplasma agassizii and Mycoplasma testudineum. Other microorganisms can also be associated with URTD, but as secondary pathogens. These include Pasteurella testudines, viruses such as herpes or iridovirus, and several fungal organisms.

Mycoplasmosis is transmitted through the primary route of direct contact, typically when one animal has nasal secretions. The mycoplasmal organism lacks a cell wall and therefore is not very stable in the environment, being easily susceptible to desiccation. Therefore, the organism has adapted the ability to enter the area between cells of the nasal passages and enter a dormancy stage, waiting an opportunity when the immune system wanes.

The clinical disease of Mycoplasmosis is hallmarked by rhinitis and conjunctivitis. Signs of illness can manifest as quickly as several weeks after exposure.  Mycoplasma strains can vary in their virulence and extent of clinical expression.  Presentation of the illness can be cyclic, emphasizing the chronic nature of the disease. Clearance of infection is rare, although sub-clinical disease can last for years, prior to return of clinical signs.

Environmental stressors are often associated with initial infection and clinical recurrence. Sub-optimal husbandry, inadequate nutrition, cold damp conditions, and increased population densities are associated with the disease.

Once exposed to the mycoplasmal organism, the organism adheres to the epithelial cells of the nasal passages, leading to damage to the normal cells. The immune response attacks the invading organism, creating thick mucoid discharge that can obstruct nasal breathing, Accumulations of mucoid and secondary infections can lead to erosion of the nasal cavities, further compromising the immune system of the sinuses. Chronic infections result in scarring of nasal tissue further decreasing the function of the upper respiratory tract.

Diagnosis of URTD can be achieved through the direct culture of mycoplasma, polymerase chain reaction detection of the DNA of the organism or the detection of antibodies to the disease. 

Mycoplasmas are generally difficult and time-lengthy to culture. Blood access is sometimes difficult making antibody testing problematic. Nasal swabs for the detection of the DNA of mycoplasma are easy to obtain, results received relatively quickly, are fairly inexpensive and therefore the preferred test.

Treatment resolves around targeted antibiotics whether topical to the nostrils or given systemically. Antibiotic injections are usually easy to administer, even by novice owners, after instruction presented by a veterinary clinic.

This is a condition that requires treatment and will not go away on its own. If symptoms are evident, please make an appointment with a veterinarian familiar with tortoise care. A list of veterinary specialists are posted on this website.