AN OUTLINE ON TREATING 'RNS' OR RESPIRATORY DISEASES IN CHELONIA

by A. C. Highfield

RNS or ‘URTD’ are words, or more properly, acronyms, guaranteed to raise serious concerns in all tortoise keepers. Both terms refer to one of the most common symptoms of respiratory disease in chelonians.

Respiratory diseases fall into two recognized groups. Upper respiratory tract disease (URTD) affects the sinuses and nasal area. This is the condition also known as ‘RNS’ or ‘Runny Nose Syndrome’.  Lower respiratory tract disease (LRTD) affects the trachea and the lungs. The conditions may be combined, and may occur simultaneously or sequentially in many cases. A problem may initially show up as a nasal discharge, but can rapidly progress to full-scale LRTD, including pneumonia, for example.

Symptoms of URTD include a persistent nasal discharge, conjunctivitis (inflamed or puffy eyes), and in some cases, an inflamed and reddened mouth.  Symptoms of LRTD are open mouth breathing as the animal struggles to breathe, a foamy or thick mucus discharge from mouth, ‘gurgling’ noises and other signs of respiratory distress, including the head being held at an unusual angle or increased movement of the front limbs. Either hyperactivity or lethargy may accompany the condition. The precise sub-set of symptoms observed is very variable, and often depends upon whether the condition is chronic or acute.   In the case of aquatic turtles, there may be an inability to swim, with listing in the water. They may ‘hang’ near the surface or even stay out of the water entirely due to the difficulty experienced in breathing. All of these are extremely serious symptoms and they demand immediate professional veterinary attention. If you observe symptoms that include open-mouth breathing, gasping, weakness or ‘deep’ respiratory sounds do not delay. Get help as fast as you possibly can.

Tortoises lack cilia and a diaphragm – this dramatically reduces their ability to cope with deep lung infections, or to cough. It is one reason why such conditions can prove so devastating in such a short time. Radiography (X-rays) can help in diagnosing pneumonia.

Tortoises suffering from acute LRTD almost invariably require treatment with injected antibiotics, and intensive care. This article concentrates instead upon what to do if you tortoise or turtle instead demonstrates a chronic condition.

What are the causes?

There is no easy answer to this. All kinds of organisms have been implicated – bacterial pathogens, fungal pathogens, mycoplasma and viruses, for example, are all suspected, sometimes in isolation, sometimes together. The first thing to do if you have an ‘RNS’ tortoise is to get a swab for culture. Check for bacteria and fungal infections. The results may prove very useful in determining future treatment.

Do not ignore simple causes. Some are initiated by nothing more than local irritation caused by a foreign body in the nose. Grass seeds, hay particles, grit and even food particles have been responsible. Such cases often involve a discharge from one nares (nostril) only. We advise ‘flushing’ the nares of affected tortoises twice daily with sterile saline solution and antibiotic drops. We do this using a blank (i.e., without needle) hypodermic to first blow air through, followed by a second syringe containing saline and antibiotic (again without the needle). A 10:1 ratio of saline and enrofloxacin is recommended. The syringe is simple pressed against the nares and ‘flushed’ backwards. During this process a surgical pad is held against the roof of the mouth. After ‘flushing’ this can be examined for pus, blood or other debris.  If pus or blood is present this may well indicate the presence of an internal abscess in within the nares.

Provided the nares are clear, we then follow up by giving antibiotic drops twice daily in each nares. These are delivered by tilting the tortoise backwards, and dropping them on to the nares during inhalation. Typical drops include those based on the drugs gentamycin, ofloxacin, or chloramphenicol.  Simultaneously, we recommend that treatment involving antibiotics by injection should be undertaken; some useful drugs in this context include Marbocyl  (vetoquinol) at 5mg/kg and Baytril (enrofloxacin) at 10mg/kg every 24-48 hours depending upon severity, for a full course of 10 doses. Other drugs that have proved useful include Fortum/Fortaz (ceftazidime) , Pipril (piperacillin) and oxytetracycline (consult your vet for dosage information).

It is very important that possible causal factors are eliminated. Do not use substrates that encourage mould growth, for example. These include ‘rabbit’ pellets or similar materials. Some very nasty lung infections have followed use of such products.

Isolate affected animals completely. Allow no contact whatever, and wash your hands and any feeding utensils carefully. Never – ever – mix species. Mixing species and allowing ‘new’ animals to meet ‘old’ animals is quite simply the number one cause of these problems in captive collections. Quarantine new animals of the same species for at least 18 months. Quarantine different species indefinitely. We have heard of keepers with several affected animals keeping them all together. This may appear logical, but it is not. Constant re-infection will occur in these circumstances. When we recommend ‘complete isolation’ we mean precisely that. Individual isolation.

Affected animals should be maintained in optimum conditions. It is especially vital that they should be allowed to bask properly in order to boost their own immune response. Cold, damp conditions must be avoided at all costs. Substrate choice is also critical.

There is, then, no simple and universal answer to this problem. Good diagnosis, good laboratory work, good support and removal of specific causal factors will all play a role in successful treatment. Prevention is the best cure of all, and avoiding all contact with potential carriers of ‘alien’ pathogens is probably the single most effective way to avoid your animals becoming afflicted in this way.

IMPORTANT POINTS TO REMEMBER

Isolate all affected animals completely.

Aggressive antibiotic treatment involving nasal drops and injections may be required.

Be alert to the possibility of deterioration and consequent pneumonia.

Prevention is the best cure! Do not mix species and be especially careful when acquiring new animals.

                                                           © A. C. Highfield/Tortoise Trust