Captive Husbandry

It is critical for the reptile veterinarian to review the husbandry practices used by the chameleon owner, as most of the problems described here are related to poor husbandry. Specific recommendations should be made, and proper husbandry should be stressed to the owners.^1,2,3,4 The https://chameleonacademy.com is an excellent online resource.

Nutritional Secondary Hyperparathyroidism (NSHP)

Juvenile (growing), young, gravid females, and adult chameleons maintained indoors under poor husbandry conditions are the most susceptible to NSHP. As with other reptiles, the disease is usually the result of low dietary calcium and/or insufficient vitamin D. Excessive phosphorus in the diet can also lead to NSHP.

The most common clinical findings in chameleons with NSHP include stunted growth, soft mandibular and maxillary bones, and deformities and fractures of long bones. In advanced cases, spinal deviations may occur with associated spinal cord involvement. Paresis or paralysis of rear limbs and/or obstipation may result. Dystocia and reproductive-related problems may occur in female chameleons with inadequate calcium reserves. Radiographs can be used to identify and characterize fractures and the severity and extent of the bone pathology.^3,4,5

Treatment for NSHP in chameleons is similar to other lizards, including oral calcium glubionate (230 mg/ml at 1 ml/kg orally every 12–24 hours), vitamin D, and supportive care. Fractures will often heal with medical treatment, proper supplementation, and a “cage rest” approach by temporarily reducing cage size and lowering branches to avoid falling/trauma.

Long-term management should include improving the calcium-to-phosphorus ratio of the dietary intake. It is important to feed invertebrates a high-quality, balanced diet (gut loading), followed by dusting them with a calcium and a vitamin D3 supplement just prior to feeding them to the chameleons. Providing specific feeding stations for chameleons (such as a deep plastic cup hanging from branches in the enclosure) allows them to easily catch and consume food items before the dusted supplement falls off.

Additionally, ensuring safe exposure to ultraviolet light (UVB) through natural unfiltered sunlight or appropriate full-spectrum bulbs (ultraviolet light in the appropriate B range of 285–310 nm) is important. Prognosis is good to guarded, depending on severity and duration. Spinal involvement with associated neurological deficits results in a more guarded prognosis.

Hypovitaminosis A

Chameleons presenting with hypovitaminosis A typically have a history of low-performed vitamin A supplementation. Usually, insects are being fed a poor diet and are only being dusted with a calcium/vitamin D supplement or a multivitamin that has only beta-carotene but no preformed vitamin A.^4,5

Clinical signs of hypovitaminosis A include eye problems, respiratory infections, neurological dysfunction, spinal kinking, dysecdysis, and increased formation of hemipenal plugs. Research in the panther chameleon fed a restricted vitamin A diet resulted in these same clinical signs described, along with increased frequency of dystocia in female chameleons.² Treatment for hypovitaminosis A involves giving a parenteral vitamin A solution (vitamin A palmitate, 100,000 IU/ml; vitamin D3, 10,000 IU/ml; and vitamin E, 20 IU/ml) at a dose of 2000 IU vitamin A/30 gm body weight orally every seven to 10 days for two to three doses. The parenteral drug works well orally and may be safer when used in this manner.^4,5

Because of concerns about the over-supplementation and the possible toxicity of preformed vitamin A in reptiles, several companies producing reptile multivitamins are utilizing vitamin A precursors such as beta carotene instead of preformed vitamin A in their products. However, the amounts, type of vitamin A precursor, and ability of chameleons to utilize these precursors endogenously to manufacture vitamin A is unknown. Therefore, it is recommended to use a multivitamin (for dusting insects) with some preformed vitamin A several times weekly to avoid hypovitaminosis A.

Additionally, feeding insects a beta carotene-rich diet (such as green leafy vegetables, carrots, and sweet potato) prior to feeding them to the chameleons may be beneficial.^4,5

Hypervitaminosis

Organ toxicity associated with fat-soluble vitamins A and D is a common nutrition-related problem of chameleons, especially if they are housed indoors. A relationship exists between these two vitamins and their dietary level of supplementation and the amount of ultraviolet exposure (UVB) in chameleons.^2,4,5

Vitamin A

Excess vitamin A supplementation may interfere with the metabolism of vitamin D3, resulting in NSHP. Excess vitamin A supplementation may also lead to organ toxicity (renal, hepatic). Gular edema is a common clinical sign of organ dysfunction.^4,5

Vitamin D3

Excess vitamin D3 supplementation—especially in combination with calcium—may result in organ toxicity. Metastatic calcification and gout/pseudo-gout are common sequalae. Gular edema is a common clinical sign of these problems. Additionally, pseudo-gout has been noted in veiled chameleons fed a heavy supplemented vitamin D3 and calcium-based diet in combination with restricted levels of vitamin A.^4,5 The pseudo-gout (calcium hydroxyapatite) deposits usually appear as irregular firm swellings over joints in the limbs and on ribs. These swellings must be differentiated from true gout, abscesses/osteomyelitis, and cellulitis. Fine-needle aspirate and cytology or biopsy can be used to reach a diagnosis. Radiology may be useful in screening for metastatic calcification and/or pseudo-gout, bloodwork may indicate extremely elevated plasma calcium values in cases of hypervitaminosis D. Reproductively active female chameleons may also have elevated calcium levels as a normal physiological occurrence. As with iguanas, elevations of phosphorus and reduction or reversal of the 2:1 calcium-to-phosphorus ratio in plasma is more sensitive than uric acid for detecting renal disease.^4,5,6 Liver disease is more difficult to assess from blood chemistry values alone. Bile acids may prove to be helpful, but liver biopsy may be the most effective method of diagnosing liver disease.

Treatment for hypervitaminosis is difficult because the clinical disease is usually well advanced by the time the chameleon is presented (i.e., gular edema with renal failure). Aggressive fluid therapy (20–25 ml/kg per day), evaluating the diet and reducing high levels of fat-soluble vitamins, providing unfiltered natural sunlight, and the use of phosphorus binders such as calcium glubionate (230 mg/ml) at 1 ml/kg orally every 12–24 hours or aluminum hydroxide (Amphojel) at 100 mg/kg orally every 12–24 hours may be helpful in managing renal disease.^4,5 Surgical intervention to remove gout or pseudogout if isolated to a single joint or limb may be useful to reduce discomfort associated with these lesions. Non-steroidal anti-inflammatories such as meloxicam may be contraindicated with renal disease. Tramadol at 10 mg/kg orally once daily may be helpful in cases of gout and pseudogout.

Renal Disease

One of the most common causes of death in chameleons is renal disease. Renal pathology is commonly noted at necropsy and on histopathology.^4,5 Similar to the green iguana, the etiology for renal disease may be multifactorial and is not yet well understood.⁶

Possible causes include imbalances in the fat-soluble vitamins A and D, inadequate exposure to UVB irradiation, chronic bacterial infection (possibly from low-grade dental disease), or exposure to toxins. Additionally, one of the most likely causes of these renal changes could be chronic dehydration. Exposure to low humidity or inadequate watering methods could lead to renal failure, especially in conjunction with these other possible etiologies.^4,5,6 Clinical signs are usually vague but include anorexia, depression, weight loss, and weakness. Other common signs include gular edema, generalized edema, exophthalmia, and enophthalmia. For other clinical signs, diagnostics, and possible treatment, see the Hypervitaminosis section above. Ensuring adequate hydration by maintaining proper humidity and providing a method to encourage and monitor water intake is critical. Also, “showering” chameleons with a misting system or on a wooden perch in the bathroom shower for 20–30 minutes once to twice weekly may help avoid subclinical dehydration.

Follicular Stasis and Dystocia

Most chameleons are oviparous (some chameleons are live-bearing, such as the Jackson’s chameleon), and both follicular stasis (pre-ovulatory) and true dystocia (post-ovulatory) are common presentations for females.^3,4,5,7 Unfortunately, healthy young female chameleons will generally tend to become reproductively active even when housed alone and thus, owners must be made aware of this potential risk. Numerous factors may predispose females to follicular stasis and dystocia, including stress, poor nutritional status, disease, and the lack of a proper nesting sites.^4,5,7 Providing exposure to ultraviolet light (UVB) and adequate levels of vitamin A and vitamin D3 may be one of the most important factors in preventing dystocia and other reproductive problems in chameleons.^2,4,5

Reproductively active female chameleons typically present for anorexia, behavior changes, and an enlarged coelom. Owners are often unaware that their pet is gravid, although breeders may also present a chameleon for suspected dystocia. A diagnosis is typically made by historical review, coelomic palpation, and/or possible visualization of calcified eggs seen through the thin skin over the coelom. If not obvious from the physical examination, radiology and ultrasonography can be useful to evaluate these females for follicular stasis or oviductal eggs. It is important to differentiate the two conditions as they may involve different management approaches. Follicular stasis may resolve without oviposition or egg/fetus removal as vitellogenic follicles can be resorbed. Oviductal eggs or fetuses must be passed by the chameleon or surgically removed. If follicular stasis is diagnosed, these females can be monitored with ultrasound to see if they eventually resorb the follicles or ovulate.⁷ If these females are pets and in generally good health, ovariectomy may be the best option to resolve this current situation and eliminate this condition in future seasons. If oviductal eggs or fetuses are identified, then providing oral calcium supplementation, proper nesting sites, and monitoring of the female’s status can be offered.⁷

Unfortunately, most truly egg-bound chameleons are presented well past their due date and in distress. These females have often already attempted to oviposit and may have laid some—but not all—of their eggs or have laid none.

In this author’s experience, the use of oxytocin for dystocia in chameleons is limited. It is often difficult to determine if a dystocia is obstructive or non-obstructive in chameleons and if a true obstructive dystocia, oxytocin is contraindicated. As mentioned, chameleons are generally presented well past their “due date,” thus increasing the likelihood of an obstructive dystocia. Radiology can be used to rule out a true physical obstruction; however, ova or fetuses that are retained past normal oviposition or birth often develop fibrous adhesions to the oviductal mucosa. Once adhered the use of oxytocin may result in torsion and or rupture of the oviduct.⁷ Therefore, there is a small window of opportunity for oxytocin to be effective. If used for a non-obstructive dystocia where a portion of the clutch (litter) has been laid or if obvious intense nesting or straining is occurring, then oxytocin is best initiated within 48–72 hours of such activity.⁷ The chameleon should be warmed to an appropriate physiological temperature, well hydrated, and parenteral calcium given if indicated based on her condition and diet review prior to giving oxytocin. A dose range of 5–20 IU/kg IM for oxytocin is used by this author starting with the lower end of the dose range and increasing the dose on subsequent doses if no response is initiated. Dosing can be repeated in six to 12 hours. If two doses have been given with no response, medical therapy will likely not be effective.⁷ If medical treatment has failed or is not indicated based on timing and conditions, the chameleon should be stabilized for celiotomy. Exploratory celiotomy may be performed to remove adhered, retained oviductal eggs and to perform a salpingotomy (in true breeding animals) or ovariectomy or ovariosalpingectomy as indicated.^7,8 Egg yolk coelomitis can occur with both pre- and post-ovulatory egg binding and is an indication for surgery as soon as the patient is stable.^7,8

Respiratory, Sinus, And Ocular Infections

Bacterial infections of the respiratory system are common in chameleons. Signs of respiratory disease include increased mucus in the oral cavity, increased stridor with breathing, open-mouthed breathing, and hyperinflation of the lungs. Frequently, the sinuses of the head are involved and bumps or swellings on the top of the head between the eyes will often occur. These may often be associated with the nasolacrimal duct system.^4,5 Respiratory and sinus infections are typically associated with eye problems. Discharge from an affected eye(s), swelling in the retrobulbar and periocular areas, and/or holding the eye(s) closed are common ocular signs. Also, like iguanas, chameleons have salt glands in their nares, so some sneezing and discharge of clear/white fluid from the nares is normal.

Tracheal culture, deep culture of the lining of the sinus, or culturing fluid from sinuses are useful in directing treatment. Typically, gram-negative bacteria such as Pseudomonas spp., Aeromonas spp., Klebsiella spp., and Proteus spp. are isolated from these infections.^4,5 These problems are often related to underlying vitamin A deficiency (see hypovitaminosis A above).

Treatment of respiratory infections in chameleons should be aggressive and initiated early. Based on culture and sensitivity results, when possible, the use of a systemic antibiotic should be initiated (see antibiotic formulary below), swellings involving the sinuses should be opened for drainage, and purulent material should be removed. Based on culture and sensitivity, a variety of ophthalmic drops or ointments can be used on the eyes or in the sinuses. Nebulization therapy with an appropriate antibiotic may also be beneficial in treating chameleons with severe respiratory infections. Generally, antibiotic treatment should last a minimum of 30 days or longer. A review of the diet may indicate the need to supplement with vitamin A. Other husbandry factors that may contribute to respiratory/sinus and ocular problems include poor hygiene of water sources and insect cultures, poor ventilation, and improper environmental temperatures.^4,5

Stomatitis and Dental Disease

Stomatitis in chameleons usually involves the mucous membranes along the lips, the commissures of the mouth, or sometimes the tongue. Clinical signs include anorexia, inability to close the mouth completely, loss of symmetry to the mouth, and inability to use the tongue. Prior to treatment, it is useful to collect a deep culture of oral lesions to help guide antimicrobial treatment. Aggressive initial debridement, drainage, and flushing with diluted betadine should be followed by systemic (see formulary below) and topical antimicrobials. Good choices of topical drugs include 1% silver sulfadiazine cream, gentamicin sulfate ophthalmic ointment or drops, and ophthalmic quinolone drops.

Chameleons have acrodont teeth (not rooted but simply attached to the surface of the mandibular and maxillary bones), which predisposes them to dental disease and potentially osteomyelitis. This unique dentition results in a gum line along the lateral surface of the mandibular and maxillary bones which can be readily permeable to bacteria.^4,5,9 Regular oral exams should be done to inspect the gum line for signs of discoloration, irregularities in surface, and loss of tissue. If suspicious lesions are present, gentle curettage with dental instrumentation is useful to assess soft tissue and bone involvement. Radiographs may also be useful to determine bone involvement and presence of osteomyelitis. Deep culture of lesions is important for management, and general anesthesia with dental cleaning, aggressive surgical debridement, and curettage may be necessary. Appropriate systemic antimicrobials (minimum of four to six weeks of therapy) and supportive care should be initiated immediately. The prognosis for chameleons with mandibular and/or maxillary periodontal osteomyelitis and loss of bone is fair to guarded depending on severity and progression. Lifetime dental prophylaxis with an oral cleansing product (Maxi Guard, Oral Gel) utilized to gently clean the oral cavity one to two times weekly for life may be necessary to reduce progression and minimize recurrence of osteomyelitis.^4,5,9

Abscesses, Cellulitis, and Osteomyelitis

Abscesses are common in chameleons and are typically the result of damage to the skin. Trauma from sharp edges in cage materials, bite wounds, or scratches from cage mates or other animals will often result in abscesses. Damaged nails from screen injuries or from pulling chameleons off branches, or dysecdysis of the toes often results in abscessation of toes, subsequent cellulitis, and osteomyelitis.

Abscesses must be treated aggressively. The prognosis is guarded if they progress to cellulitis, joint involvement, and osteomyelitis. Treatment involves surgical intervention for aggressive debridement and drainage. Whenever possible, infected bone should be surgically removed. Often, amputation of involved limbs may be necessary for the chameleon to recover. Radiology is useful to assess degree of bone and joint involvement. Culture and sensitivity of the abscess wall or deep within the affected tissue is important in determining the appropriate antimicrobial therapy. Four to six weeks or even several months (osteomyelitis cases) of systemic and topical antimicrobial therapy may be necessary for resolution.

A combination of systemic antimicrobial therapy and initial aggressive flushing with diluted chlorhexidine or betadine may be necessary. For topical treatment of deep wounds involving bone, a solution of DMSO and enrofloxacin (22.7 mg/ml injectable solution) using 7.5-ml DMSO and 0.5-ml enrofloxacin or DMSO and amikacin (50-mg/ml injectable solution) using 7.5-ml DMSO and 0.25-ml amikacin can be applied once or twice daily to encourage deep local penetration of antibiotics.^4,5 It is important that the wounds are first flushed or cleaned prior to applying the DMSO solution. Silver sulfadiazine creme (1%) is also a good topical medication and can be packed into wounds once daily after flushing. Abscesses on the head and around the eyes may involve the sinus system (see Respiratory, Sinus, and Ocular Infections and Hypovitaminosis A sections).

Parasitic Infections

Nematodes, cestodes, coccidia, flagellates, and amoebae are all intestinal parasites commonly found in chameleons.^3,4,5,10 Clinical signs of parasitism include weight loss, anorexia, regurgitation and vomiting, and malformed and malodorous stools. Parasitic infections are not seen as often in the more commonly captive-bred species such as veiled chameleons and panther chameleons. But nematodes (primarily oxyurids) and coccidia can still be found in captive-born chameleons, and fecal exams should be performed. Flagellates, amoebae, and other nematodes may also be present in captive chameleons that live in mixed collections (both captive and wild-caught reptiles kept) or facilities with poor isolation and quarantine practices.

It is important to have several fecal exams performed on every chameleon that enters a collection. Wild-caught chameleons may best be prophylactically treated with both nematocidal and cestocidal drugs (see antiparasitic formulary). To attempt to ensure that parasites are eliminated, at least three negative fecal samples may be necessary.

FORMULARY

Antibiotics (Some Examples Used by the Author)

Amikacin: 2.5 mg/kg SQ over cranial dorsum q 72 h. An initial loading dose of 5 mg/kg can be given. May cause a temporary dark color change in skin after injection. Ensure that the lizard is well-hydrated prior to and during treatment.

Enrofloxacin: 10 mg/kg PO q 24 h for 21–30 days. Be aware that parenteral dosing may cause damage to the skin and/or muscle, resulting in possible permanent skin color changes (thus, PO preferred).

Ceftazidime: 20–40 mg/kg SQ over cranial dorsum q 48–72 h for 30 days (often used in combination with amikacin or enrofloxacin).

Piperacillin: 100–200 mg/kg SQ over cranial dorsum q 48–72 h for 30 days (often used in combination with amikacin or enrofloxacin).

Antiparasitic Agents

Fenbendazole: 20-25 mg/kg PO q 7 d x 3 doses. For nematodes.

Praziquantel: 8–10 mg/kg SQ q 14 d x 2–3 doses. For cestodes.

Metronidazole: 20–40 mg/kg PO q 7 d x 2–3 doses. For flagellates and amoebae.

Trimethoprim-sulfa: 30 mg/kg PO q 24 h for 10–14 days. For coccidia.

It is not recommended to give more than one or two of these drugs simultaneously to debilitated animals, and the patient should be well hydrated during treatment.

Ivermectin: 0.2 mg/kg PO q 10–14 d x 2–3 doses. Ivermectin is another antiparasitic agent that may be used in chameleons. However, there have been reports of deaths in chameleons given this drug, so it should be used with caution.¹⁰ In most cases, the antiparasitic agents discussed previously are safer and just as effective. Ivermectin may be useful and necessary when attempting to treat lungworms, such as pentastomids, or migrating nematodes, such as filarial worms. Do not treat debilitated chameleons with ivermectin. The author has found this dose to be safe with these considerations and precautions in mind.

References

1.  de Vosjoli P, Ferguson G, eds. Care and breeding of panther, Jackson’s, veiled, and Parson’s chameleons. The Herpetological Library. Lakeside, CA: Advanced Vivarium Systems; 1995:128.

2.  Ferguson GW, Jones JR, Gerhmann WH, et al. Indoor husbandry of the panther chameleon Chameleo (Furcifer) pardalis: effects of dietary vitamins A and D and ultraviolet irradiation on pathology and life history traits. In: Garrett CM, Chiszar D, guest eds. Advances in Zoo Herpetology, Zoo Biology. 1996;15(3):279–299.

3.  Jenkins JR. Husbandry and diseases of Old World chameleons. In: Proceedings of the North American Veterinary Conference; 1992;6:687–691.

4.  Stahl SJ. Captive management, breeding, and common medical problems of the veiled chameleon (Chamaeleo calyptratus). In: Proceedings of the Association of Reptilian and Amphibian Veterinarians; 1997:29–40; Houston, TX.

5.  Stahl SJ. Pet lizard conditions and syndromes. Seminars in Avian and Exotic Pet Medicine. 2003;3:162–182.

6.  Boyer TH. Diseases of the green iguana. In: Proceedings of the North American Veterinary Conference; 1997;11:718–722.

7.  Stahl SJ, DeNardo D. Theriogenology. In: Divers SJ, Stahl SJ, eds. Mader’s Reptile and Amphibian Medicine and Surgery. 3rd ed. St. Louis, MO: Elsevier; 2019:849–893.

8.  Stahl SJ. Reproductive tract. In: Divers SJ, Stahl SJ, eds. Mader’s Reptile and Amphibian Medicine and Surgery. 3rd ed. St. Louis, MO: Elsevier; 2019:1077–1089.

9.  McCraken. H, Birch. Periodontal disease in lizards: A review of numerous cases. In: Proceedings of the American Association of Zoo Veterinarians; 1994:108–115.

10.  Barrie M, Castle E, Grow DT. Diseases of chameleons at the Oklahoma City Zoological Park. In: Proceedings of the American Association of Zoo Veterinarians; 1993:1:3.