Recognizing and Treating Common
Chelonian Illnesses
By Scott Howard 11/15/1999



    I have been an avid amateur herpetologist with an emphasis on chelonians for about 18 years.  From a very young age I housed, raised, and rehabilitated many sick and/or injured turtles and tortoises.  Most of the chelonians that I have cared for have been endemic to the eastern United States, but I have also had a number of the more common exotics.  I have worked as a veterinary technician under six different veterinarians with varying backgrounds in herpetology, herpetoculture, and wildlife rehabilitation.  I have seen that captive propagation can be beneficial to both the wild populations of rare turtles and to herpetological studies.  I disagree with the less than common or rare species being held as captive pets by inexperienced collectors where they will be a genetic “dead-end” or when they are held only for the novelty of possessing the species.  Turtles can be very fun and educational for people of all ages.  Inexperienced keepers should always start with the common and heartier species.

    Chelonians typically are long-lived and hearty animals. Some species seem to be able to live and even thrive in the most adverse conditions.  Species such as the common snapping turtle (Chelydra serpentina), the pond slider (Trachemys scripta), and the stinkpot (Sternotherus odoratus) are common in most areas of the United States largely due to this ability to survive and adapt to almost any aquatic environment.  Other aquatic and semi aquatic species can be much more sensitive to their aquatic environments.  Soft-shelled turtles (Trionichidae), many map turtles (Graptemys sp.), and diamond-backed terrapins (Malaclemys terrapin) are some of the more environmentally sensitive chelonians.

    There are numerous factors that can influence the health of all chelonians.  The three general factors that may lead to health problems are stress, diet, and environment.  I will focus here on map turtles and diamond-backed terrapins since they are some of the more delicate
specimens and tend to share similar health problems with other species while having some unique amongst themselves.  Young specimens are the most susceptible to both nutritional and pathogenic derived problems.  But hatchlings are usually less susceptible to relocation and environmental stresses.  Obtaining captive raised specimens after their first year is ideal.  Hatchling mortality is quite high when compared to older individuals.  Hatchlings also require a great amount of time and extra care to insure a near 100% survival.

External Illnesses

    Bacterial and fungal pathogens are of the most concern when assessing and treating a turtle.  The best defense against all such pathogens is to provide the turtle with a spacious clean environment that is similar to the environment in which the species occurs naturally and to provide a varied and nutritious feed.  Stressed or malnourished turtles become very susceptible to a variety of pathogens due to a decreased immune response.  Inadequate basking areas or lighting may lead to external fungal or bacterial infections.  A white, yellow, or brown film material on the head, neck, limbs, or shell of the turtle may indicate one or more of these pathogens.  These infections can also appear as a cheese like material, blisters, or as nodules on the dermis of infected specimens.  These infections are associated with several named pathogens.  The common names of some of these diseases are shell rot, SCUD, Salmonella, and body slime.  There have been more specific names placed with the causative organisms and a variety of cultures done to identify these pathogens.  I refer you to your local reptile veterinarian or "Reptile Medicine and Surgery", by Douglas Mader if you really want to know the genus or even species of these organisms.

    All external diseases are best treated in about the same manner.  Separate the infected turtle or turtles and place them into a hospital tank.  Clean and sterilize the original housing with a 1:100 dilution of chlorine bleach, clean the substrate and the container.  Rinse all chlorine from the housing before reintroducing your turtles.  Wash, brush, or scrape all foreign material from the shell and dermis of the turtle.  Allow the turtle to be submerged in a 1:100 dilution of povidone iodine (Betadine) or chlorohexadine (Nolvasan) solution for ten to fifteen minutes.  The turtle should be allowed to dry and then apply a topical ointment (Betadine antibiotic ointment or DMSO cream mixed with Nolvasan) to infected areas.  The turtles can then be placed into a hospital tank equipped with a dry full spectrum basking site (80-90F gradient over the site area).  The water temperature in the tank should be 80-82F.  The turtle's food should be supplemented with small amounts of vitamin C.  There should be enough water for the turtle to swim.  This treatment should be repeated daily as the water is changed daily in the hospital tank.  The main housing tank should also undergo some renovations to improve water quality, check for over-crowding.

    With diamond-backed terrapins a special note should be made in regards to adult males and females with shell rot.  Adult female terrapins usually shed their scutes at least once a year.  Males typically do not shed scutes except in cases of trauma or other external stimuli (i.e. barnacles).  In the case of many captive raised female terrapins, the scutes may not come off naturally.  When a new scute grows underneath the outer scute, it may not shed completely and water can get trapped between the layers.  If this water remains between the scutes for a few days then a perfect environment for fungus is created, leading to extensive shell rot.  The turtle will indicate when she is shedding her scutes by basking for long periods of time.  If air or water can be seen underneath the outer scutes or if the scutes are curling up at the edges then those respective scutes should be removed easily.  Also, remove all infectious material.  Apply Betadine antibiotic ointment or DMSO cream mixed with Nolvasan to the infected areas.  Do not apply the DMSO cream over extensive areas of the turtle.  The appearance of a gray or silvery tissue is indicative of healthy tissue regeneration.  As with any sign of external infection, prompt and aggressive action should be taken as soon as possible to prevent further complications.

    Macroscopic external parasites such as mites and leeches, or barnacles along for a ride on wild caught terrapins do not usually pose as large of a problem as the fungi or bacteria.  Leeches and barnacles can usually be removed carefully with tweezers or hemostats.  There are several commercial reptile sprays available for mites in aquariums.  The container, basking site, and the nesting areas should be sprayed with sprays approved for such.  Do not spray the turtle. If necessary submerge the turtle in a 1:100 dilution of Betadine or equivalent.  Most mites of aquatic turtles are only active on the basking site.  When the turtle returns to the water the mites should fall off or drown, but the dry areas of the aquaria must be treated.

Internal Illnesses

    Bacterial and possibly viral pathogens are of the most concern when assessing and treating a turtle for internal illness.  Again, the best defense against all pathogens is to provide the turtle with a spacious clean environment that is similar to the environment in which the species occurs naturally and to provide a varied and nutritious feed.  Stressed or malnourished turtles become very susceptible to a variety of pathogens due to a decreased immune response.  Inadequate basking areas or lighting may lead to pneumonia.  I use the term “pneumonia” to describe any form of respiratory distress that may lead to or include signs of excessive draining of mucus or other liquids from the nasal or oral openings in chelonians. If a turtle basks at night due to an external infection or other stresses then the individual may get to cool and become infected a form of pneumonia.  This can be devastating to weakened or ill turtles.  Cold drafts such as those from air conditioning vents can also leave basking turtles susceptible to pneumonia.  Supplementary vitamin C in the diet and a warm basking light goes a long way towards preventing most respiratory diseases.  I refer you to your local reptile veterinarian if any sign of pneumonia is evident.  One to three injections of gentomycin sulfate are usually sufficient to help clear the turtle of pneumonia.

    Pneumonia is one of the first infections that result from stress and one of the most difficult diseases to detect.  Early detection of all internal bacterial infections is critical to the treatment of these infections.  There are a number of signs to watch for.  An early indicator of any infection is excessive basking with a reluctance to leave the basking site.  With pneumonia this basking behavior maybe coupled with occasional gasping or other troubled breathing.   The neck of the turtle may become slightly swollen and mucus or bubbles may come out of the turtle's mouth or nose. In more advanced cases the turtle may float tilted to a side.  There may be a loss of appetite and the turtle may have trouble submerging in the water.  Swollen limbs can also occur due to some pathogens associated with pneumonia.

    Other internal bacterial infections can enter the turtle through an injury or an irritated toenail.  A serious bite from another turtle, a fish, or other animal can also cause an infection that if not treated early may cause a long slow death.  There are some bacteria associated with tropical fish tanks that are not easy to treat effectively.  Mycobacterium marinum is one such bacterium that can be dangerous to both turtles and humans.  With this infection a human can look forward to weeks or months of rifampicin therapy.  I have found little that even slows down some soft tissue infections in turtles.  Once established the limb or other infected portion will become necrotic and eventually the infection will spread to the remaining parts of the turtle.  I have heard of amputation being an only option in cases of very resistant bacteria.  I have frequently used UV sterilizers on tanks where complete water changes were a problem.  This necessarily reduces all free floating bacteria, protozoa, and fungi significantly.  If there is any signs of excess swelling, discoloration, or discharging of mucus from any portion of the turtle then refer to a qualified veterinarian immediately.  The turtle will likely need to receive systemic antibiotics, depending on the type of infection and the opinion of the veterinarian.  Cleaning all wounds early with Betadine and then applying a triple antibiotic ointment, Betadine antibiotic ointment, or DMSO cream mixed with Nolvasan should prevent any bacteria from becoming established in fresh wounds.  Oral antibiotics are not recommended for turtles due to their slow and inconsistent metabolism.

    Internal parasites are rarely a problem with aquatic chelonians.  In large numbers the intestinal parasites can be a problem.  Treatment for internal worms should only be done in instances such as: if the individual is passing visible worms, if it is a hatchling from a suspect source, or if the individual is eating well but is losing weight.  To treat for these parasites, allow the turtle to dry out for a couple of hours and then place the turtle in a solution of piperazine for about thirty minutes.  Consult your veterinarian in any case of intestinal parasites. Never give any chelonian ivermectin or any solution containing ivermectin.  This is the equivalent of turtle euthanasia.

Nutritional Illnesses

    Typically, keep the turtles in clean water, provide ample basking area with full spectrum lighting, and provide them with a varied and balanced diet.  “Sick” turtles often have acquired some type of pathogen as a result of a depressed immune system, stress, or a break down in membrane integrity.  Each of these weaknesses in a turtle's health can stem from a vitamin deficiency.  All of the veterinary costs, antibiotics, steroid injections, vitamin supplements, ointments, and medicated baths can usually be avoided if a varied and balanced diet is provided to these jewels.

    Young turtles frequently get soft or deformed shells.  This is typically a result of a calcium deficiency.  The deficiency may be in the diet or from a lack of ultraviolet light, which allows the turtle to utilize and absorb calcium present in its diet.  Vitamin D supplements can be given, but the turtles need the warm basking light to dry and prevent fungus anyway.  The full spectrum incandescent bulbs are becoming quite reasonable in cost, insure these lights do have some output in the 280-380nm range of the spectrum.  Map turtles and diamond-backed terrapins can be provided with some crushed coral in the substrate to provide them with additional calcium as needed. This is typically used with enthusiasm by nesting females.

    Turtles of all ages are prone to vitamin A, B-12, and C deficiencies.  Vitamin A insures membrane integrity.  Deficiencies in vitamin A or retinol result in a breakdown in the mucus membranes of the eyes and intestinal tract.  Swollen eyes and discharge from them are symptoms of a vitamin A deficiency.  Vitamin A is prominent in fish liver and can be obtained as cod liver oil.   Whole fish in the diet would be best to prevent this.

    Vitamin B-12 or cyancobalamin is essential for the overall health of turtles and to prevent partial paralysis.  Vitamin B-12 can be presented in trace amounts in the diet or from shrimp and some fish.  Vitamin C is present in most commercial pelleted foods when they are fresh.  Vitamin C is one of the first essentials that degrade in commercial foods, so check your expiration dates.  Small amounts of vitamin C can be supplemented in prepared foods weekly.  Vitamin C is necessary to maintain the strength of any animals’ immune system.  With a strengthened immune system turtles are much less prone to most pathogens.  Vitamin C and all other vitamins should be given according to veterinarian anytime an animal is ill.  Do not administer vitamins if you are unsure of the dosage or body weight; hypervitaminosis can have more adverse effects than some deficiencies, so consult your veterinarian.

    All chelonians typically are long-lived and hearty animals.  Map turtles, and diamond-backed terrapins are not the exceptions.  Providing the proper conditions and care, they may live well beyond 20 years.  The three primary factors affecting the health of turtles are stress, diet, and environment.  Given adequate room, proper lighting, clean water, and a balanced diet your turtles can live a low stress and a long life, and they should reproduce if given the chance.  Prevention is by far the easiest and most effective method of combating diseases and nutritional deficiencies.  Admire and observe these jewels and get involved in any conservation and public education efforts you can.