Furnishing adequate housing, a good diet, and routine parasite control will help to minimize disease in pet reptiles, as with any other animal.
Heart and Blood Vessel Disorders
Septicemia, a disease caused by bacteria in the blood, is a common cause of reptilian death. The disease affects the whole body and may occur after trauma, an isolated abscess (see Reptiles: Abscesses), an infestation of parasites, or environmental stress. Death may be sudden or occur after longterm signs of illness. Common signs are trouble breathing, lack of energy, convulsions, and loss of muscle control. A tiny purplish red spot on the skin may be found on the lower part of the stomach, and turtles and tortoises develop a redness of the skin on the lower portion of the shell. Keeping a reptile's environment clean and well maintained can be important factors in reducing outbreaks of septicemia. Affected reptiles should be isolated, and antibiotic treatments started.
Reptiles' digestive systems can be upset by viral infections, bacterial infections, protozoal infections, and infestation with parasites.
Adenoviruses may cause fatal liver or gastrointestinal diseases in certain snakes (gaboon vipers, ball pythons, boa constrictors, rosy boas, and rat snakes) and lizards (Jackson's chameleons, Savannah monitors, and bearded dragons). In bearded dragons, the adenovirus appears to be transmitted when contaminated animal droppings come in contact with the mouth. Signs of infection are more commonly noted in younger dragons but can affect adults, usually to a lesser extent. The signs are vague and include lack of energy, weakness, weight loss, diarrhea, and sudden death. The frequency of death is high in young bearded dragons, but good supportive care—such as giving fluids, force-feeding, and giving antibiotics for any secondary infections—can increase survival.
The signs of this disease in bearded dragons are similar to those caused by coccidia (see Reptiles: Coccidial Organisms) and nutritional disorders, so it is important to have your veterinarian confirm the diagnosis, which can be done by a liver biopsy.
Recovered lizards should be quarantined for at least 3 months. The length of time required for a complete recovery (with no detectable virus) is unknown, so you should not plan to sell or trade a previously infected animal.
An inflammation of the mucous tissue lining the mouth (infectious stomatitis) is seen in snakes, lizards, and turtles. Early signs include tiny purplish red spots in the mouth; firm, dry diseased tissue develops along the tooth row as the condition worsens. In severe cases, the infection can extend into the bony structures of the mouth. Bacteria that are commonly found in the mouth are the most frequent culprits. Respiratory or gastrointestinal infection may develop if the stomatitis is not treated promptly. Treatment requires the removal of any dead, damaged, or infected tissue from the wound in order to expose healthy tissue that will allow the wound to heal. The wound then needs to be cleansed with antiseptics or antibiotics. Finally, whole system antibiotics and supportive therapy should be given. Surgery may be needed in severe cases with slow-healing sores or inflamed growth. Vitamin supplementation, especially with vitamins A and C, may be helpful in some cases.
The stress of captivity coupled with a closed environment tends to cause a heavy burden of parasites that live inside reptiles. Many common internal parasites of reptiles have direct life cycles in which the offspring of the parasite can infect the same host it came from. For example, the adult parasite lives in the host's intestine, lays eggs that are passed in the animal droppings, and the eggs then infect the same host. These parasites can multiply to staggering numbers, and poor hygiene is often a factor. Every effort must be taken to rid reptiles of parasite burdens, and to rid the environment of intermediate hosts.
Treatment should be attempted when evidence of an infestation of parasites is found. Drugs called anthelmintics are usually needed to eliminate internal parasites. Many different anthelmintics—some of which are known as dewormers—are available. Your veterinarian can prescribe the one that is considered most effective for the particular parasite involved.
Roundworms of the stomach (stomach worms) are seen in lizards and, when infection is severe, can cause stomach ulcers. Numerous snakes are infected by a hookworm that lives in the upper gastrointestinal tract and causes wounds at sites of attachment. Large mineral deposits caused by this hookworm may cause intestinal obstruction.
Another group of roundworms, known as ascarids, also frequently infect reptiles. Severe wounds and death may be seen in infected snakes. Snakes infected with ascarids frequently regurgitate their partially digested food or adult worms and have no appetite. Infection may cause large masses of mineral deposits in the gastrointestinal tract; these wounds may become inflamed and filled with pus, and they may eventually make holes in the intestinal wall.
Many other species of roundworms may be found in reptiles on examination of the animal's droppings. The non-disease-causing parasites of prey items (such as the mouse pinworm) may be found when infected prey is consumed.
Protozoa are single-celled organisms, many of which can cause disease in animals. Entamoeba invadens is the most serious disease-causing protozoon of reptiles. Signs are loss of appetite and weight, vomiting, mucus-like or bloody diarrhea, and death. The disease may spread very quickly in large snake collections. Plant-eating reptiles appear to be less susceptible than meat-eating ones; however, a number of reptiles that seldom become affected or die can serve as carriers, including garter snakes, northern black racers, and box turtles. Other resistant groups include eastern king snakes, cobras (possibly as an adaptation that allows them to eat snakes), and most turtles. Most boas, colubrids (nonvenomous snakes such as king snakes, garter snakes, and water snakes), elapids (venomous snakes such as coral snakes and mambas), vipers, and crotalids (venomous pit vipers, rattlesnakes, and bushmasters) are highly susceptible. This protozoan is transmitted by direct contact with the cyst form. A veterinarian can do simple tests of the animal's droppings to look for the presence of Entamoeba invadens.
An antiprotozoal drug is usually prescribed for treatment. To help prevent transmission among reptiles, turtles and snakes should not be housed together. The potential for this disease to be passed on to humans should not be taken lightly, and strict sanitation and hygiene measures should be observed.
Cryptosporidiosis is an infectious condition caused by Cryptosporidium species of protozoa. It is often associated with regurgitating a meal, marked weight loss, and longterm reduction in strength and energy. In snakes, the organism affects the moist lining in the gastrointestinal tract, resulting in thickening of the natural ridges in the internal organs and loss of segmented movement. Often, but not always, a veterinarian can feel a mass in the stomach area. X-rays or an examination using a medical instrument called an endoscope may reveal ridge thickening. Many lizards, including Old World chameleons and Savannah monitors, are affected primarily in the intestines. A veterinarian can diagnose cryptosporidiosis by performing certain tests on the animal's droppings, on the regurgitated food, or through a medical procedure called an endoscopic gastric biopsy. While several treatments have been suggested, none have consistently worked. Intensive supportive care will often stabilize and help prolong the life of the affected reptile.
Cryptosporidiosis is a disease that can be transferred from animals to humans; however, it now appears that the strains commonly found in reptiles do not affect humans or other mammals.
Although hormonal (endocrine) disorders do not appear to be common in reptiles, diabetes mellitus (defects in insulin action) has been reported in turtles and tortoises. Signs of diabetes in these reptiles include sugar in the urine and abnormally high levels of sugar in the blood. A dramatically increased appetite might also be noticed.
Eye and Ear Disorders
Infections of the eyes are possible in all reptiles. Ear infections are most likely to occur in turtles.
Eye Abscesses and Conjunctivitis
Abscesses can occur below the clear covering over the eyes in snakes, and conjunctivitis occurs in other reptiles. The severity of this condition ranges from mild inflammation to inflammation involving all the tissues of the eyeball. It may occur as a result of the spreading of an infection of the mucous tissue lining the mouth (see Reptiles: Infectious Stomatitis). Topical antibiotic ointments are used in turtles and lizards without spectacles (the clear covering over the eyes). In snakes and lizards with spectacles, surgery is needed to drain the abscess and flush the space below it and the tear duct with an antibiotic solution. Some affected reptiles, especially turtles, may need supplemental vitamin A.
Ear infections occur in turtles, most often in box turtles and aquatic turtles. Swelling may be seen at the eardrum, and firm, dry diseased tissue is present. Many bacteria have been found to cause ear infections. Drainage of the ear and whole system antibiotics are required. Surgery may be needed to scrape the inside surface of the area and to remove any abnormal growths or other tissue. The area should be flushed with diluted povidone-iodine or a similar product for a few days to prevent premature closure and to keep the area clean. Ear infections may occur after a vitamin A deficiency; injections and dietary supplementation of vitamin A may be beneficial.
Bone and Muscle Disorders
Abnormal beak growth, which interferes with feeding, occurs in turtles and tortoises; it is often associated with poor nutrition, a deficiency of calcium, or both. A calcium deficiency may cause the skull to become distorted as it develops. This interferes with normal positioning of the upper and lower beaks when the jaw is closed and can affect wear of the beaks. Feeding excessive amounts of dog food or monkey chow may contribute to this condition. Treatment consists of trimming or grinding the mouthparts into a more normal shape. The condition usually occurs again due to the original disorder of the upper and lower beaks growing in uneven positions, and longterm maintenance is required. “Chewable” foods that allow for some natural beak trimming and shaping should be provided to turtles and tortoises in captivity. Items that might be suitable include crunchy insects such as beetles, stink bugs, grasshoppers, and large mealworms. Fresh raw vegetables, such as bok choy and kale, are also good because they require tearing and more use of the mouth.
Brain, Spinal Cord, and Nerve Disorders
Star-gazing is a neurologic disorder with signs that include mental dullness, abnormal posture, and an inability to move forward normally. It is seen in, but not restricted to, snakes, and is characterized by a severely twisted neck, creating a “starward gaze.” A retrovirus that causes a viral meningitis/encephalitis in certain snakes (boas and pythons) is the most commonly diagnosed star-gazing syndrome. This syndrome is referred to as inclusion body disease due to the presence of characteristic masses of virus particles inside cells, referred to as inclusion bodies (see Reptiles: Inclusion Body Disease of Boid Snakes).
Other possible causes of star-gazing are heat damage, trauma, and infections caused by bacteria or other organisms. Bacterial meningitis or encephalitis usually results from an infection being spread through the blood or bacterial particles circulating in the blood from an abscess elsewhere in the body. The outcome of the disease varies, depending on the cause, but the outlook is generally guarded. Whole system antibiotics are usually necessary in bacterial cases. An injection of a corticosteroid may help to reduce the inflammation associated with these infections. Because sores may heal slowly, an early response to therapy is rarely seen, and good supportive care (including fluids and nutrient supplementation) is essential.
Nutritional disorders can be caused by an imbalance in various nutrients, including protein, vitamins, and minerals (see Reptiles: Nutrient Requirements), or by defects or other diseases that prevent proper utilization of nutrients.
Malnutrition and Dehydration
Reptiles that do not have an appetite may need to be force-fed to correct severe deficiencies. This is a process that is best directed by your veterinarian, because feeding a malnourished reptile with severe dehydration can lead to additional, serious health problems. Initial feedings should replace fluids and electrolytes. Dehydration is recognized by skin folds along the sides of the animal, saggy skin, and in severe cases, sunken eyes.
Fluids can be given by soaking the reptile in water, by letting the reptile drink the water, or by having a veterinarian give it by injection. The soaking of mildly dehydrated reptiles is an easy and practical means of rehydration. For reptiles that are alert enough, fluids given by mouth are preferred to other methods; however, if necessary, a veterinarian will know the best method and the correct amount of fluids to provide.
A malnourished or starving reptile is similar in appearance to one that is dehydrated. Loss of tissue below the skin, noticeable bones, and a gaunt, sunken appearance are noted. Initial force-feedings under the supervision of a veterinarian are best done with a prepared mixture rather than with whole animals. Once initial force-feedings have been done, small whole animals can be force-fed to snakes and meat-eating lizards. The prey should be coated with egg white and then gently advanced into the back of the mouth, after which the reptile is allowed to swallow.
Environmental factors such as temperature, light, and humidity should be set to the best conditions for all reptiles showing a loss of appetite. Fluids and nutrients will not be used properly if conditions are not optimal.
Gout is not only a disease of humans; it is also seen in all orders of reptiles. It occurs when the amount of uric acid in the blood is too high. Two forms of gout have been reported. Visceral gout affects the organs, and articular gout affects the joints. X-rays often show mineralized salt deposits from uric acid in the affected organs and joints. Visceral gout can be due to too much protein in the diet (primary visceral gout) or to other causes such as dehydration or kidney damage (secondary visceral gout). Gout can be very painful, causing discomfort to the point that some reptiles refuse to move, eat, or drink.
Primary visceral gout is treated by correcting the diet. Secondary visceral gout is treated by trying to correct the underlying problem, be it dehydration or kidney failure. Drugs that have traditionally been used to treat gout in humans may be effective in reptiles if the diagnosis is made early. However, the outlook for recovery is poor in advanced cases. Medical treatment usually must be longterm, because signs of gout often occur again if treatment is discontinued. Euthanasia (putting the animal to sleep) should be considered in reptiles that appear to be in pain and have no appetite.
Lung and Airway Disorders
Respiratory infections, including pneumonia, are common in reptiles and can be affected by many things, such as parasites infesting the respiratory system or the whole body, unfavorable environmental temperatures, unsanitary conditions, another disease occurring at the same time, malnutrition, and vitamin A deficiency. Open-mouth breathing, discharge from the nose, and difficulty breathing are frequent signs. Septicemia (see Reptiles: Heart and Blood Vessel Disorders) may develop in severe or prolonged cases. Treatment consists of improving environmental factors (such as cleanliness and temperature) and starting whole system antibiotics. A veterinarian will be able to advise you on the proper antibiotic treatment. Reptiles with respiratory infections should be kept at the mid to upper end of their preferred temperature range. Increased temperatures are important not only to stimulate the immune system but also to help increase the output of mucus in the respiratory tract. Turtles often have an underlying vitamin A deficiency, and an injection by a veterinarian may help. Many turtles treated for pneumonia fail to improve until after treatment for vitamin A deficiency.
Paramyxovirus infections are more common in viper snakes, but have been reported in nonvenomous snakes as well. This highly contagious virus causes mostly breathing problems; it is not unusual to see discharge from the nose, open-mouth breathing, dried pus in the mouth, and labored breathing. It appears that the virus is passed from one animal to another through the moisture in their breath. Due to the severe inflammation caused by paramyxovirus, affected animals often develop additional bacterial infections. Neurologic symptoms, including tremors and abnormal posture (extreme stiffness with severe arching of the back and the head thrown backward), are sometimes seen.
A snake with a respiratory infection that does not respond to treatment with supportive care, antibiotics, and nebulization (a way of providing medication in the form of a fine mist or aerosol) may be infected with paramyxovirus. Tests can be performed by a veterinarian as screening tools to help eliminate infected animals and prevent carriers from entering noninfected collections. There is no specific treatment, but supportive care and antibiotics may be useful. Affected snakes should be isolated and strict hygiene used.
Reptiles are prone to a variety of skin diseases and disorders. Good sanitation practices—such as regular enclosure cleaning, providing fresh water, and removing uneaten food—can help prevent infection and parasite infestation.
Abscesses are pus-filled sores, often accompanied by inflammation, and usually caused by bacterial infection. They are seen in all orders of reptiles. Often, abscesses are triggered by traumatic injury, bite wounds, or poor environmental conditions. Infected sores under the skin are seen as small lumps or swellings. Other conditions that may appear similar include parasitic infections, tumors, and hematomas (semisolid masses of blood in the tissues, caused by injury, disease, or a clotting disorder). A number of organisms, often more than one kind at a time, have been recovered from abscesses in reptiles. Small, localized abscesses should be completely cut away to avoid a recurrence, which does happen often. Larger abscesses should be cut open, followed by thorough treatment of the wound. The lining of the abscess must be scraped to remove as much material as possible. Appropriate whole-system antibiotics may also be needed.
Dermatophytosis, a fungal infection of the skin or nails, has been described in all reptiles. In most cases, an injury to the skin provides a point of entry for the fungus. Turtles and tortoises with fungal infections of the shell can be treated by removing the dead, damaged, or infected tissue and applying an antiseptic or disinfecting solution. For skin infections, an oral antifungal drug is usually needed, although antifungal creams have also been used with good effects. Exposure to ultraviolet light also may be beneficial. (Also see Reptiles: Diseases Caused by Fungi.)
Dysecdysis refers to an incomplete or abnormal shedding of skin. Low humidity and other stresses, including decreased thyroid function, skin parasites, nutritional deficiencies, infectious diseases, and lack of suitable abrasive surfaces, may all contribute to an abnormal shed. Often, eyecaps or circular bands on the tail or digits are kept. Eyecaps are best treated by applying an ointment made especially for the eye area twice a day for several days until the remaining skin either falls off or can be grasped with a pair of fine forceps and removed. Be patient—eyecaps should never be forced off because of the possibility of damaging the spectacle (the transparent covering over the eyes).
Stubborn, retained skin is best treated by soaking the reptile in warm (77 to 82°F [25 to 28°C]) water for several hours and then pulling gently with a gauze sponge. A humidity chamber also works well. This can be as simple as a 10-gallon aquarium with an undertank heater in which wet bath towels are placed. The top can be covered with a light cloth to increase humidity levels, but excessive heat must be avoided and can be relieved by allowing more ventilation. It is easier to prevent than to treat an abnormal shed, so make sure that your reptile is free of disease and parasites, is kept at the correct humidity level, and has abrasive surfaces available to help slough its skin.
Parasites that live in the reptile's skin are often a problem with wild-caught and newly acquired reptiles. Infestations are best prevented by thorough examination and a period of quarantine for all new animals entering a collection.
Mites are distributed worldwide, and most species of reptiles are affected. Reduced energy and, in heavy infestations, anemia (a blood condition in which there are too few red blood cells) due to blood loss may occur. The skin of affected reptiles appears coarse, and incomplete and inadequate skin shedding may occur. The mites are tiny—less than 1.5 millimeters long—and are often found near the eyes, folds around the face or neck area, or any other indentation on the reptile. Mites may also transmit disease-causing organisms from other infected animals.
Mites are visible to the naked eye but are hard to see in small numbers. If mites are suspected, placing the reptile on a piece of white paper and gently rubbing it to remove mites will allow the mites to be seen. Affected reptiles often spend a great deal of time soaking in water to drown the mites. If you examine the water dish, you might see the drowned remains of mites.
There are many methods of treatment. In all cases, cages should be cleaned thoroughly, and you should throw away substrate materials, branches, and disposable cage furniture. Newspaper bedding should be used until treatment is completed to help with frequent cleaning and to get rid of egg-laying sites. A veterinarian will be able to tell you the type of mites your reptile has and provide advice on eliminating them from your pet and its enclosure (such as recommending a safe insecticide).
Keep in mind that any enclosure in which insecticide is used should be well ventilated, and any water containers should be removed while spraying and replaced when spray has dried. Do not use any product without consulting your veterinarian, as some may be safe in certain species of reptiles, but deadly to others.
The larvae of trombiculid mites (chiggers) are seen occasionally but are not considered to cause disease.
Ticks are frequently found on reptiles, and have been associated with many diseases. Heavy infestations may result in anemia (a blood condition in which there are too few red blood cells) due to loss of blood. Certain ticks may cause paralysis, with muscle wasting at the site of the bite. Ticks can be removed manually. Whole system antibiotics are often needed due to infections associated with multiple skin bite wounds and, potentially, with transmission of disease-causing bacteria.
Leeches have been found on the legs, head, neck, and in the mouth of a variety of turtles and crocodilians.
Turtles frequently have skin maggots. Botflies create a skin wound in which to lay their eggs. These hatch into bots that live in their cyst-like structures until they are mature enough to leave the wound. The wounds often resemble a lump under the skin; on closer inspection, they have an opening that is often lined by a black, crusted material. Your veterinarian can remove the bot by slightly expanding the natural opening and using a forceps to extract it from the skin. The wound is then flushed with an antiseptic or disinfectant, and an antibiotic ointment is applied. Whole system antibiotics are needed in reptiles that have multiple wounds. Skin maggots may also occur in existing wounds, and the maggots must be manually removed and the underlying wound treated with topical and whole system antibiotics as needed. During heavy fly season, it is recommended that turtles be housed indoors or with screens over their enclosures to offer some protection.
Scale rot (ulcerative or necrotic dermatitis) is seen in snakes and lizards. Humidity and unclean environments appear to be the main factors that cause this condition. Moist, unclean bedding allows bacteria and fungi to multiply. When coupled with exposure to animal droppings, this can cause small skin sores. Secondary infection with other bacteria may result in septicemia and death if untreated. Reddening of the skin, death of the skin tissue, slow-healing sores on the skin, and a skin discharge are common. Although sores are sometimes caused by skin injuries, they more often develop from within. This is the case with classic scale rot in the ball python, in which the disease can develop even when animals are kept under perfect conditions. The condition starts with bleeding into scales, followed by small, round, raised areas of inflamed skin filled with pus that eventually lead to open and slow-healing sores. Treatment with whole system antibiotics, topical antibiotic ointment, and excellent hygiene are essential.
Blister disease was originally considered to be a separate disease, but it is now recognized as simply an early stage of scale rot. The skin has small, round, raised areas of inflammation filled with pus or blisters. These may go away without development of slow-healing sores if treatment is started early. A low-grade heat injury may seem like blister disease due to the possible development of fluid-filled blisters.
Septicemic Cutaneous Ulcerative Disease (SCUD)
Septicemic cutaneous ulcerative disease (SCUD) in turtles is a bacterial disease in which the scales are pitted. The turtle may shed dead skin with an underlying pus-filled discharge. Loss of appetite, lack of energy, and bleeding red spots on the shell and skin are seen; liver damage is common. Whole system antibiotics are recommended. Good sanitation is critical in preventing septicemic cutaneous ulcerative disease.
Another shell disease of turtles is caused by Beneckea chitinovora, a bacteria commonly found in crustaceans. Reddening of the skin and pitting of the shell with slow-healing sores is seen. Septicemia (bacteria in the blood) is uncommon. Treatment with topical iodine is recommended. Feeding your turtle crayfish is often the cause of this condition and should be discouraged.
Disorders Affecting Multiple Body Systems
Some diseases affect more than one body system in a single animal, and other diseases have different effects in different species.
Bacterial diseases are common in all reptiles. Most infections occur in reptiles whose immune systems are already weakened, most likely due to illness. Because of this, it is important not only to determine the type of bacteria that is causing the disease but also to correct environmental and nutritional deficiencies that contribute to ill health. Treatment with antibiotics for a specific type of bacteria will not be successful without ensuring the proper heat, light, hydration, nutrition, and so on.
Several coccidial organisms have been reported to cause disease in reptiles. The severity of disease varies with the species of the coccidial organism and the type of reptile affected. These parasites can increase to tremendous numbers, especially in ill or diseased reptiles. The eggs of these parasites can survive for weeks in a dehydrated condition. Thorough daily cleaning is necessary to remove all animal droppings and contaminated food and water. Insects and other food items must be removed on a daily basis, as they are another source of contamination (for instance, crickets may eat the parasitic eggs while gathering fluid from the animal's droppings). Treatment should include an antimicrobial drug and may take 2 to 3 weeks. Even under the best conditions, treatment will get rid of these organisms in only 50% of cases. However, reducing the number of these organisms is still important, and a veterinarian should periodically check coccidial numbers.
Diseases Caused by Fungi
Excessively high humidity, low environmental temperature, already having another disease, malnutrition, and stress from poor husbandry may be factors in the development of diseases caused by fungi in reptiles. Little is known about the cause, development, and effects of fungal infections of the whole body, which can develop over a long period, but maintaining good sanitation and nutrition seems to reduce the number of these infections. Antifungal drugs may be used to treat whole-body infections, but reports of successful treatment in reptiles are few. For fungal infections that are limited to one area, surgical removal of the mass created by the fungus followed by local wound treatment may be helpful. Basidiobolus species, which can cause disease in mammals, are found in animal droppings of normal reptiles.
The most frequent sites of fungal infection in reptiles are the skin and respiratory tract. Slow-healing internal sores developing on gastrointestinal tissues have been associated with some fungal infections. Disease of the liver, kidneys, and spleen may also be caused by a fungal infection. Few signs other than weight loss—or in the case of respiratory infection, difficulty breathing—are seen before death. Animals may continue to eat until a few days before death.
Flagellates (a type of protozoal micro-organism), especially Hexamita species, can cause urinary tract disease in turtles and tortoises and intestinal disease in snakes. A veterinarian with expertise can usually differentiate between the species and will be able to identify most of these organisms. An anthelmintic or antiprotozoal drug is usually prescribed for treatment.
Herpesviruses have been found in freshwater turtles, tortoises, and green sea turtles. In freshwater turtles, the virus may kill liver cells. In tortoises, the virus may cause death of mucous membrane cells in the mouth accompanied by loss of appetite, regurgitation, and discharge from the mouth and eyes. Herpesvirus infection can be diagnosed by a veterinarian.
Treatment in tortoises usually includes isolating the animal and providing supportive care, as well as giving an antiviral drug (either orally or in the form of an ointment applied directly to mouth sores).
Inclusion Body Disease of Boid Snakes
Boa constrictors and several species of pythons are most commonly affected by inclusion body disease, which is caused by a retrovirus. Boas are considered to be the normal host for this retrovirus because so many (up to 50% of those tested) are infected and they can harbor the virus for years without signs. In essence, inclusion body disease should be considered in every sick boa. Signs may appear suddenly due to any factor affecting the immune system and include a history of failure to absorb food, loss of appetite or weight, secondary bacterial infections, poor wound healing, skin ulcers, and regurgitation. Blood tests may show an increase in the number of white blood cells during the severe phase of the disease, but as the disease progresses, white cell counts tend to decline to levels that are below normal. As the disease becomes longterm (chronic) some boas will exhibit neurologic signs ranging from mild facial tics and abnormal tongue flicking to failure of the snake to right itself when laid on its back and severe seizures.
Pythons are thought to be an abnormal host of the retrovirus because the course of disease is more severe and neurologic signs are more extreme. Although the active disease can linger for months or more in boas, most pythons die within days or weeks of the appearance of signs.
Breeding, fight wounds, and contamination due to animal droppings coming in contact with the mouth are common ways of transferring the virus. Casual handling of an infected snake and then a normal snake does not appear to create enough exposure to cause infection. However, any reptile with a weakened immune system may be susceptible under the right circumstances. The snake mite is likely responsible for the spread of the virus in large, well-maintained collections.
Inclusion body disease is not curable, and many pet owners may choose to euthanize affected snakes. However, snakes can be isolated and treated with supportive measures to ease pain and symptoms. It is essential that you do not sell infected specimens or their offspring, as this has caused the disease to spread worldwide.
Infection of the cloaca (the common passage for urine and feces in reptiles) is often caused by kidney stones or other hard accumulations of the lower intestine, urinary tract, or reproductive passages. It is characterized by swelling and bloody discharge from the cloaca. Accumulated mineral deposits, similar to kidney stones, may form when vitamin or mineral imbalances occur. These should be manually removed by a veterinarian and followed by dietary correction. When abscesses occur in the lower intestine, urinary tract, or reproductive passages, the infection can move within the body and inflame the brain and muscles throughout the animal. Upward-moving urinary or genital tract infections are common after infectious cloacitis. Aggressive treatment, including surgery to remove damaged or infected tissue from the wound, local wound treatment, and appropriate whole body antibiotics, is required. Your veterinarian may need to examine feces from your reptile to identify whether the infection is caused by parasites.
Sores of internal organs may occur as a result of an infection in the blood. Abscesses of the female reproductive system are common and may lead to an infection of the abdomen. In this case, surgery is required, as whole system antibiotics alone are rarely successful.
Certain disease-causing flatworms (trematodes) infect the arteries and veins of turtles, and the mouth, respiratory system, kidneys, and the ducts that carry urine from the kidneys to the bladder of snakes.
Tapeworms are found in all orders of reptiles but are rare in crocodilians. The complex life cycle of tapeworms and the need for intermediate hosts limit the number of cases in captive reptiles. When present, segments of a tapeworm's body may be found in the lower intestine, urinary tract, or reproductive passages of the reptile, or typical tapeworm reproductive cells may be found in animal droppings. The infective larvae of some tapeworms may be found as soft swellings in the layer of connective tissue below the skin. These larval stages may be removed surgically.
Roundworms (nematodes) are found in all orders of reptiles. They are often microscopic, and include examples such as pinworms and hookworms. These parasites can inhabit the intestinal tract of reptiles; certain larvae are seen in the respiratory tract and respiratory cellular waste product, as well as in the mouth. They can sometimes be found in the animal's droppings. Infections often are mild but may lead to more serious diseases, such as pneumonia. In severe cases, death may result.
Some roundworm larvae may penetrate the skin, rather than entering the reptile through its mouth. This type of infection often goes unnoticed until the reptile is overwhelmed by parasites. Close attention to the immediate removal of animal droppings and urine-soaked areas of the substrate, as well as good sanitation practices, help to reduce parasite burdens in captive reptiles.
Skin sores caused by the spirurid worm (Dracunculus species) may be seen in reptiles. Numerous species of spirurids infect the stomach lining, body cavity, or blood vessels. These worms require an organism such as a mosquito or tick that transmits disease-causing microorganisms from infected animals to other animals, so they are less common in captive-bred reptiles or in reptiles that have been in longterm captivity. Treatment consists of increasing the environmental temperature to 95 to 98°F (35 to 37°C) for 24 to 48 hours. However, some “cool-adapted” reptiles may not tolerate this treatment.
Tongue worms (pentastomes) are found in a wide variety of reptiles, with variable abilities to cause disease. Infections are occasionally associated with signs of pneumonia, but these parasites can inhabit any tissue, and signs will vary with their migration path. Tongue worms were first noticed in tropical poisonous snakes; however, they have been seen in other reptiles as well. Treatment with the usual drugs (anthelmintics) often fails to eliminate these worms. In some cases, it may be possible for the veterinarian to use an endoscope to locate and mechanically remove all the adult worms. Recognition of these infestations is important because tongue worms are thought to present a risk of infection to humans. Euthanasia (putting the animal to sleep) is a valid consideration due to public health concerns.
Mycobacterial infections are often associated with chronic wasting (a gradual loss of body condition caused by longterm infection). These infections generally affect the lungs of turtles and tortoises, whereas lizards, snakes, and crocodilians show small mass growths on their internal organs. The drugs required to fight these infections cause liver damage in reptiles, and their longterm use is unlikely to be safe.
Cancers and Tumors
Tumors are much more common in reptiles than previously thought. In addition to spontaneously developing cancerous (neoplastic) diseases, tumors have been associated with parasites and certain viruses. Tumors in reptiles are usually easily identified through various tests performed by a veterinarian. Once tumors are identified, treatment protocols similar to those used in other animals could be adapted. Your veterinarian will be able to recommend the appropriate treatment.
Retroviruses found in Russell's vipers (viper virus), corn snakes (corn snake retrovirus), and California king snakes may sometimes be associated with malignant tumors.
European green lizards appear to pass viral particles from one lizard to another through bite wounds. The resulting papillomas (small growths) are approximately 1/16 to ¾ inches (2 to 20 millimeters) in diameter and may be single or multiple. While there are no signs in the initial phase, affected lizards may lose their energy and appetite and die. Diagnosis requires a veterinarian to test for signs of viral particles. Single masses can be surgically removed, but regrowth is common. Isolating any affected lizards may be the only way to prevent spread.
A papilloma-type virus also appears to affect Bolivian side-neck turtles and appears as white, oval skin sores distributed over the head. Slow-healing shell sores are also seen, primarily on the lower portion of the shell. Diagnosis requires a veterinarian to test for signs of viral particles. Treatment requires supportive care and treatment of signs; affected animals should be isolated from other turtles.
Last full review/revision July 2011 by Roger J. Klingenberg, DVM