Aggressive fungal pathogen discovered in panther chameleons

Aggressive fungal pathogen discovered in panther chameleons

Tiermedizin Science

Fungi of the genera Nannizziopsis and Paranannizziopsis have long been known to cause severe skin diseases in various reptiles. These include species feared in herpetocolture such as CANV (Chrysosporium Anamorph of Nannizziopsis vriesii) and Nannizziopsis dermatitidis, which are apparently obligate pathogens. Now, a similar skin fungus has been detected in panther chameleons in Florida, USA.

Nine adult panther chameleons (Furcifer pardalis) were taken from a wild population in Florida. They were first housed in groups of two or three chameleons in screen cages with natural and artificial plants at a private keeper. A ReptiSun 5.0 lamp and a conventional light bulb were used. The animals were fed with crickets and zophobas every second day and supplemented with vitamins and calcium. All nine panther chameleons, plus a tenth that was captured later, were finally given to the United States Department of Agriculture (USDA) for a series of experiments. They were kept individually in steel aviaries outdoors.

Subsequently, the eight remaining panther chameleons were also examined. In fact, all but one of the chameleons were found to have either missing claws or swelling of the hands and feet, small skin wounds, circumferential proliferation on the body and/or yellow and black skin lesions. Fungal PCR was no longer carried out, but infection with the same pathogen was suspected. All nine panther chameleons still alive were treated with 25 mg/kg terbinafine and 5 mg/kg voriconazole, both given orally once daily.

After six weeks, the panther chameleons were examined again. The skin lesions were still present, in two animals the hand and foot swellings had decreased. After eleven to twelve weeks of treatment, all symptoms had disappeared in seven chameleons. The skin lesions had developed into scars. Only two chameleons still showed swelling in the foot area, but less than at the beginning of treatment. After 14 weeks of therapy, another panther chameleon died. The autopsy revealed kidney and organ damage as the cause of death. Since the contribution of the medication used to the death of the chameleon could not be ruled out, the therapy was terminated in week 15 for six of the eight panther chameleons. The two panther chameleons that still showed swelling of the feet were treated for another two weeks.

This case report is the first detection of Paranannizziopsis australasiensis in chameleons. So far, this fungal pathogen has only been found in green iguanas and Eastern bearded dragons in herpetoculture and in Tuataras, skinks, geckos, and snakes in nature. It remains unclear where the panther chameleons became infected. Three of the screen cages used in the initial private husbandry had previously been inhabited by Veiled Chameleons (Chamaeleo calyptratus) and Knight Anoles. The private keeper had disinfected the terrariums with chlorine bleach. The rest of his reptile population showed no skin lesions. The aviaries used later at the USDA had been empty for years and had previously only been inhabited by small birds. It is possible that the fungal pathogen had been introduced via potted plants from nurseries that regularly observe native reptiles on the premises. However, Paranannizziopsis australasiensis has not been found in any other wild reptile species in Florida to date.

The most likely scenario seems to be that the chameleons were already infected before they were caught in Florida, but the disease only broke out later. The original animals of the population could have been infected by bearded dragons in the pet trade a good decade ago. A latent infection with a late onset is supported by the fact that most of the skin lesions in this case report were found in winter, after temperatures had dropped below 10°C. Moreover, before the onset of symptoms, so-called “thermal limit trials” were carried out, in which the animals were briefly exposed to extreme temperatures of up to 45°C and 6°C. Another chameleon from the same population was caught at a later time and also developed skin lesions, which indeed suggests an infected population in Florida.

A free-ranging chameleon population infected with Paranannizziopsis australasiensis could pose a huge risk to native reptiles. The fungal pathogen is known to be highly infectious and aggressive. In addition, free-ranging panther chameleons in Florida are now being captured by dealers and sold to private owners, which could result in the spread of the disease in private reptile populations. Further research is urgently needed to clarify the extent of the current occurrence of Paranannizziopsis australasiensis in Florida, both in herpetoculture and in the wild.

Dermatomycosis caused by Paranannizziopsis australasiensis in nonnative panther chameleons (Furcifer pardalis) captured in Central Florida, USA
Natalie M. Claunch, Colin M. Goodman, Madison Harman, Mariaguadalupe Vilchez, Savanna D. Smit, Bryan M. Kluever, James F.X. Wellehan, Robert J. Ossiboff, Christina M. Romagosa
Journal of Wildlife Diseases (4), 2023
DOI: 10.7589/JWD-D-22-00018

Unusual parasite discovered in Furcifer campani

Unusual parasite discovered in Furcifer campani

Tiermedizin Science

Physiologists, microbiologists and veterinarians from the USA recently described an unusual case of a parasite infestation in Furcifer campani. This is probably the new discovery of an as-yet-undescribed chameleon parasite.

In 2021, 11 Furcifer campani had been imported from Madagascar as wild-caught specimens and were kept privately. Two months after importation, unusual behaviour was noticed in one male and one female of the group. The two animals basked in the sun for unusually long periods of time, specifically seeking out temperatures of 29-30°C as well as places with enormously high UV indices compared to the other chameleons. Within the next three months, both Furcifer campani visibly lost weight, although the food supply was increased and a good food intake could be observed. At the same time, a lighter skin colouration was noticed. Faecal examinations by flotation were negative. Finally, both chameleons became lethargic, and closed their eyes during the day. A bloated abdomen and increased watery faeces were observed. Both Furcifer campani died.

Histological examination confirmed muscle atrophy and cachexia. Massive infiltration of the liver and gastrointestinal tract with large amounts of spores could be detected in both chameleons. The spores proved positive in Grocott’s methenamine-based silver stain and the PAS stain. Morphologically, the spores were classified as Dermocystidium-like. Investigations by PCR revealed a high similarity with Dermocystidium salmonis, but the exact pathogen could not be determined with certainty.

The genus Dermocystidum is a parasitic microorganism that is classified as a protist (it is neither a fungus nor an animal or plant). It is interesting that they have so far been known mainly from fish and amphibians, occasionally also from mammals. So far, not a single case of infestation with Dermocystidium has been described from reptiles. It could therefore be an undescribed, new species that is possibly even chameleon-specific. Effective therapy is not yet known.

A unique disease presentation associated with a mesomycetozoean-like organism in the jeweled chameleon (Furcifer campani)
Michael Nash, Emily A. McDermott, Ashley K. McGrew, Juan Muñoz, Dayna Willems
Journal of Herpetological Medicine and Surgery, February 2023
DOI: 10.5818/JHMS-D-22-00033

Parasite treatment in leaf chameleons

Parasite treatment in leaf chameleons

Tiermedizin

Last weekend, the autumn meeting of the AG Amphibien- und Reptilienkrankheiten (working group on amphibian and reptile diseases) took place. With over 500 members, the AG ARK is one of the strongest sub-groups of the DGHT and at the same time the largest association of veterinarians for amphibians and reptiles in Europe. Accordingly, the autumn meeting in Münster was fully booked as usual. Besides the main topic of the meeting, Asian turtles, one veterinarian presented a case report on parasite treatment in leaf chameleons.

In this case, 7.5 subadult and adult Brookesia stumpffi (5 wild-caught, 7 German offspring from different husbandries) were acquired for a breeding project. Fecal examinations of all terrestrial chameleons were carried out. Masses of Choleoeimeria spp., presumably Choleoeimeria brookesiae, were found in flotation and native preparations of almost all terrestrial chameleons. In addition, there were isolated co-infections with Heterakis spp. and trematodes. Strongylid-like eggs with thin shells and larvae as well as adult nematodes were found in the feces of several animals. A treatment protocol with Baycox 50 mg/ml (Elanco Animal Health, Rathausplatz 12, 61352 Bad Homburg, Germany, active ingredient toltrazuril) on days 1, 7, and 14 and Panacur 10% (Intervet Germany, Feldstraße 1a, 85716 Unterschleissheim, Germany, active ingredient fenbendazole) on day 3 and 13 proved successful. The diluted solutions were given into the mouth with a 100 µl pipette. Fecal examinations at the beginning of quarantine and on days 14, 28, and 42 after treatment were suggested as a practical protocol for veterinarians.

The biggest problem during treatment was reinfection with coccidial oocysts from the environment. The leaf chameleons reinfected themselves, among other things, via left feeders and fecal remains on climbed gauze and living plants. Successful quarantine was finally achieved under the following parameters: individual keeping without visual contact in separate terrariums, daily exchange of kitchen paper on the floor and a freshly cut elder branch, use of new gloves for each chameleon, slow-moving food from bowls disinfected daily in boiling water, weekly disinfection with ready-to-use Interkokask® (Albert Kerbl GmbH, Felizenzell 9, 84428 Buchbach, active ingredient chlorocresol). Extremely strict compliance with all cleaning and disinfection measures was necessary.

Parasite treatment in leaf chameleons (Brookesia stumpffi)
Dr. Alexandra Laube
Proceedings of the 57th Workshop of the WG Amphibian and Reptile Diseases, Focus: Asian Turtles
Münster, 04 – 06 November 2022