Kei Island Blue-tongue Skink

Blue-tongues (Tiliqua sp.) are by far the most popular hardy skink—if they are captive-bred. Wild-collected specimens may be fussy in their diet and not particularly pleasant in disposition. Wild-caught specimens of New Guinea blue-tongues are still imported: Tiliqua gigas and Irian Jaya blue-tongues, Tiliqua unnamed sp (There is currently debate about the placement of this lizard taxonomically as it has features of the Australian and Indonesian species.) The Irian Jaya is regularly available as captive-bred specimens while the New Guinea is only occasionally available. Two subspecies of Australian blue-tongue skinks are commonly available as captive-bred specimens, the northern and eastern (T. scincoides scincoides and Tiliqua scincoides intermedia). Unfortunately, many of the Australian blue-tongues appear to be interspecific hybrids. Some color morphs have been selectively bred such as sunglow, flame, and high orange. Other bluetongue subspecies that are occasionally bred are Tanimbar Island Tiliqua scincoides chimera and Kei Island Tiliqua gigas keyensis.  An excellent pictorial guide to the blue-tongue skinks is available at www.bluetongueskinks.net

The remaining Australian species are coveted for their odd appearance or beautiful patterns and may fetch high prices despite being common in the wild. The few specimens outside of Australia of Centralian, blotched, and Western bluetongues and shinglebacks are likely the result of smuggled specimens (or breedings of smuggled animals) as no legal exports for the pet trade have occurred in decades. It is possible a few specimens came out of the zoo industry but given the legal requirements now in place it is difficult to imagine any make their way to the pet trade from this route any more. The pygmy bluetongue is actually an endangered species and should not be in the pet trade!

Kei Island Blue-tongue Skinks are extremely variable in pattern and color

Blue-tongues may be sexed by ultrasound, endoscopy, or by careful morphometrics.  Neonates may have their hemipenes “popped” but this can cause damage if done improperly; anesthesia may be needed for full relaxation for this technique to succeed.

Husbandry

In my opinion, captive-bred blue-tongue skinks are much easier to raise than bearded dragons. Blue-tongue skinks are more tolerant of lower temperatures and have lower ultraviolet-B requirements. They do not require live food and do well on a diet of green leafy produce mixed with fruits, legumes and other vegetables, and an animal protein source; many keepers use various prepared foods (e.g., Harrison’s Bird Diets High Potency Coarse Pellets, ZuPreem's Monkey Biscuits, semi-moist dog or cat food, ZooMed’s canned grasshoppers, etc.) as an enhancement to the salads. Young growing skinks need regular supplementation with a calcium product containing vitamin D3 but otherwise eat a diet similar to the adult. Blue-tongue skinks are very tolerant of handling and become quite tractable as they get larger and eventually become “lap lizards” with regular gentle handling. Blue-tongue skinks are much longer-lived than bearded dragons, often reaching their teens and twenties.

The downside to blue-tongue skinks is that most specimens are not very tolerant of other skinks except during mating season so they have to be housed one to an enclosure. If you are keeping one as a pet, it will not mind being kept alone. Many pet blue-tongue skinks will become quite friendly and beg to come out when they spot their main care-giver and some people have even been given their blue-tongue skinks free reign of their home (which I do not recommend).  However, many wild-caught ones maintain a defensive attitude for years, hissing, wriggling, voiding their cloacas, and even biting when handled, and are NOT good “pets.” Another downside is that blue-tongue skinks produce larger fecal boluses than bearded dragons and thus have more of an “odor presence” when their cages are dirty.

All Blue-tongue skinks are keenly aware of their surroundings and most can develop a bond with their care-givers.

A simple blue-tongue skink cage is 36 to 48 inches long, 18 to 24 inches deep, and 18 to 24 inches high. They will climb rocks and thick branches but do well in cages without a lot of height. Some people raise and breed them in sweater box racks designed for small boas and pythons (supporting the conclusion that UVB is not necessary for adults if the diet provides vitamin D3) but I prefer a more spacious and visible enclosure. In drier climates a mix of damp sphagnum moss and cypress mulch works well as a substrate while in more humid areas aspen shavings or newspapers may be good choices. A humid hide box should be provided (filled with damp sphagnum) even in wetter climates; this is essential in Arizona and other dry climates! A hot spot of 85 to 95°F at one end of the cage is sufficient and may be provided by a combination of an under-tank heat element and a basking spotlight. I believe UVB should be provided for optimum health, particularly for neonates and juveniles, and recommend that a UVB bulb (e.g., Reptisun 5.0) should be provided for at least 8 hours a day and be positioned so that the skink is no more than 18 to 24 inches away from its rays.  If the bulb is above a fine mesh screen, you may want a higher output bulb (e.g., Reptisun 10.0) as this screen diminishes penetration of the UVB rays. A water bowl should be available that is in a sturdy untippable crock. When the skink is in shed, the crock should be large enough for it to soak its whole body; at other times a smaller crock will do. The cage should be well ventilated.

A 12-hour photoperiod works well. Breeding skinks requires photoperiod manipulation and cooling and is outside the scope of this web article.  You may see http://www.bluetongueskinks.net for more information on this topic.

Neonatal skinks and young skinks should be fed daily as much as they will eat. At least one feeding a week should have a calcium and D3 supplement (e.g., Rep-Cal with D3), one feeding with a suitable multivitamin containing vitamin A (e.g., Zoomed's Reptivite), and the other feedings should be supplemented with calcium citrate or calcium lactate. I tend to use human vitamin products as their quality control is better regulated than pet vitamins. I crush a pill as I need it and discard the unused portion as the quality declines once the tablets are crushed and exposed to air and moisture. Adult skinks do well on two or three feedings a week with weekly multivitamin supplement and calcium supplements on other feedings. Blue-tongue skinks have to have their food intake monitored or else they readily become obese.

Common Medical Problems

Nutritional secondary hyperparathyroidism (NSHP) should be rare in blue-tongue skinks but unfortunately it is not. Baby skinks are often raised on diets deficient in calcium and without exposure to UVB or a dietary source of vitamin D3. The tips of the tails are often kinked followed by abnormalities of the lumbar spine. Bowing of the mandibles is a sign of very advanced disease. If caught early, treatment may prevent further skeletal abnormalities from developing but will not cause the abnormal features to become normal. Calcium glubionate daily helps correct NSHP in combination with an appropriate  diet. The diet described above will prevent NSHP. UVB lighting is needed, too.

It is rare to find an adult blue-tongue skink with all ten toes intact.  If a cage gets too dry during the shed process, it is common for skin to be retained on the toes and the tip of the tail (as well as on the eyelids). Soaking in warm shallow baths (1/2 inch of 90ºF water) for 60 minutes usually loosens the skin so that it may be gently removed. Toe necrosis and sloughing may happen if several sheds have built up and cut off circulation. The same may happen to the tail tip. A lack of vitamin A in the diet contributes to the retained shed on the toes and tail. It also causes the shed to be retained around the eye and makes the blue-tongue skink squint. It is often misdiagnosed as an infectious conjunctivitis. Raising the environmental humidity to at least 75% and soaking and peeling the shed from the eyelids in combination with oral vitamin A supplements (e.g., a drop of a 10,000 IU vitamin A gel cap once a week is often sufficient to treat this) or occasionally vitamin A injections will often effect a seemingly miraculous cure.

Many blue-tongue skinks that have lived with another blue-tongue skink are missing toes from bite wounds; some fights actually result in loss of an entire limb (or crushing of the jaw).  Since blue-tongue skinks move in a snake-like manner, they typically do not appear impeded when missing a majority of toes or even a couple of limbs. Recent injuries should be cleaned and debrided. The nonsteroidal anti-inflammatory drug (NSAID) meloxicam and nontraditional anti-inflammatories (AVIx Booster) and appropriate antibiotics may be needed.  This frequently progresses to osteomyelitis and amputation is needed in moderate to advanced cases. Osteomyelitis usually requires 3 to 6 months of antibiotic therapy to be effective. Cytologic aspirates and cultures should be performed to rule out gout as a cause of bone lysis. Some bite wounds may penetrate the coelomic cavity and carry a guarded prognosis, particularly if organs are eventerated. Antibiotic therapy should target anaerobes and gram-negative bacteria (eg, penicillin-G and enrofloxacin, among other combinations).

Abscesses may be external or internal. A frustrating condition is weight loss that doesn’t respond to supplemental feeding, anthelmintics, and antibiotics; an internal abscess is often the underlying cause and can only be diagnosed with celioscopy or an exploratory celiotomy. (Celioscopy is often needed to diagnose the wasting blue-tongue skink.) This usually reflects a breakdown in husbandry and is more common in recently imported blue-tongue skinks.

Stomatitis is a condition that suggests fighting or a diet that has too much soft food. Blue-tongue skinks are omnivorous but should have a diet with lots of crunchy and leafy vegetables to clean the teeth as they eat. Unfortunately, stomatitis often results in permanent changes to the shape of the gingiva and even the bone around the tooth socket. Prevention is key. Treatment includes broadspectrum antibiotic with anaerobic coverage, anti-inflammatories, topical cleansing, and a reformulated diet to ensure proper nutrition and proper texture.

Respiratory infections are heralded by sneezing, clear to catarrhal nasal discharge, open-mouthed breathing, or “drooling.” This usually follows inappropriately low temperatures (often during seasonal changes in the household where the cage heating elements no longer can keep up with the cooler room temperature) and poor brumation practices. Provision of background temps of 88ºF and hotspots of 95ºF are key to healing. Daily soaks in shallow warm water are helpful. Antibiotics are almost always needed. Anti-inflammatories are helpful. Clean the nares and perform choanal flushes as needed to remove debris. Resistant infections warrant tracheal cultures or lung washes. Due to ossification of the scales, radiographs to assess pneumonia are typically unhelpful.

Kei Island Blue-tongue skinks are not commonly bred in captivity.

Wild-caught imported blue-tongue skinks suffer from a variety of parasites, particularly amoebas and flagellates.  Nematodes and other helminths are occasionally seen. I find a combination of fenbendazole and metronidazole is more effective at eliminating flagellates than either alone. Nematodes may need fenbendazole or ivermectin repeated in 2- to 3-week intervals. Pyrantel palmoate also may be effective.

Wild-caughts often suffer from “maladaptation” and require set-ups with minimal intrusions to adjust to captivity; some fail to thrive due to underlying illnesses and may even have permanent damage from dehydration or thermal stresses that occurred during the various events prior to or during importation. Endoscopy should always be considered to diagnose a nonresponsive illness.

Copyright 2009
Kevin Wright
Arizona Exotic Animal Hospital, LLC
744 N Center Street
Mesa, AZ 85203
info@azeah.com