Parasites

Milben an Furcifer petteri

Parasites are a common problem among chameleons, especially in wild caughts or captive breds from large collections. Generally, there are endoparasites, that settle inside a chameleon, for example in its lungs or inside the gut, and there are ectoparasites that only live on the skin of a chameleon. Not all parasites are equally harmful to chameleons: Some are already a big problem in low infestations, others are rather harmless. By the way, you can recognize only very few parasites with the naked eye in feces.

This article gives an overview of parasites that occur in chameleons, their transmission, and life cycle. To make it a little easier to understand, some class and family orders have been left out. We do not recommend any treatment options on this page, because diagnosis and treatment of a parasite infestation should always be done in consultation with an experienced reptile veterinarian.

1. Endoparasites
1.1 Coccidia and cryptosporidia
1.2 Flagellates
1.3 Microsporidia
1.4 Trematodes (flukes)
1.5 Cestodes (tapeworms)
1.6 Nematodes (roundworms)
1.6.1 Rhabditis
1.6.2 Strongylidae
1.6.3 Spirurida
1.6.4 Filarioidea
1.6.5 Ascaridida (maw worms)
1.6.6 Oxyurida
1.6.7 Capillaria (hair worms)
1.7 Amoebas
2. Ectoparasites
2.1 Mites
2.2 Ticks

If you like to read directly about a certain parasite, just click on one of the links above.

  1. Endoparasites

1.1 Coccidia and cryptosporidia

Kokzidien-Oozysten unter dem Mikroskop

Eimeria oocyst in feces of Furcifer pardalis

The nightmare of chameleon keepers: Every other larger collection has a problem with coccidia. Sporulated coccidia oocysts on feeders that had contact with infectious feces infect chameleons, or they are infected while hatching by oocysts sticking to the eggshell. Infections via contaminated water or stuff that has oocysts sticking on its surface are also possible. These parasites infest the intestinal mucosa, bile ducts, and kidneys. Often the infection is self-limiting: In adult chameleons, a stable immunity may occur with chameleons showing no signs of disease although they still have a massive infestation. Under stress (mating, change of location, rearing young animals) or suboptimal husbandry, coccidia can reproduce well and lead to severe disease including intestinal inflammation and diarrhea. Since every animal experiences some “stressing” things in life that could make coccidia increase, coccidia should never be seen as harmless.

Among coccidia, there are Eimeria spp. and Isospora ssp., while cryptosporidia are not counted anymore as coccidia. Unfortunately, coccidia oocysts are extremely persistent. Under advantageous conditions, they remain infectious for more than one year. Oocysts sporulate in humid and warm conditions (optimum is 25-30°C, under 10°C development suspends). Temperatures above 35°C damage the oocysts, but coccidia are resistant against most chemical disinfection agents. Cryptosporidia are even more durable. They survive cold to -20°C and heat up to 65°C, and may be killed with heat > 70°C lasting more than 10 minutes (each area of the cage has to be treated under this temperature at least this time). At 5°C, Cryptosporidia remain infectious up to five years (!) long. Since popular disinfection agents do not damage the oocysts, you have to talk to your reptile vet about the use of ammonia or chlorocresol (thoroughly speak with your vet about health protection before use!). High resistance against “simple” disinfection agents and lack of quarantine is probably the reason for coccidia being widely spread among chameleon husbandries.

Isospora

Isospora oocyst under the microscope

Please pay attention to the fact that cryptosporidia and coccidia may be a zoonosis, which means they can be transferred from animals to humans. In immunocompromised humans (children, pregnant women, old or sick) cryptosporidia, for example, may lead to severe diarrhea.

1.2 Flagellates

Flagellates is an umbrella term for a bunch of single-cell organisms. Some may be found inside a chameleon’s feces without any corresponding disease, but some need treatment. Infection occurs orally by intake of cysts from the environment or rather by mobile, vegetative stages from feces and urate. Monocercomonas spp. for example (belong to Trichomonads) or Hexamites infest among others urogenital tract, liver, and lungs. In case of a severe infestation of weakened animals, flagellates may cause digestion problems.

1.3 Microsporidia

Microsporidia are rare problems in chameleons but may kill the animal if infected. In most cases, Pleistophora is involved. Chameleons may become infected orally, via aerial distribution, via spores or in case of viviparous chameleons, directly in the oviduct from the female to her offspring. The cyst-like spores of these protozoa live in muscles and other tissues (they are obligatory intracellular, which means they can only survive inside cells). Microsporidia can be killed with heat over 70°C, 10% formalin, or 70% alcohol.

1.4 Trematodes (flukes)

Trematoden unter dem Mikroskop

Trematodes under the microscope

Among flukes, especially Spirorchiidae are pathogenic (sickening). Chameleons become infected through oral intake of parasite stages. The worms can clog very small blood vessels and thus result in a supply shortage of the affected organ area. Chameleons rarely have trematodes, most cases affect wild caughts due to the fact that most flukes need one or two intermediate hosts (a snail or another invertebrate). This intermediate host will be eaten by the chameleon and this is when infection takes place.

1.5 Cestodes (tapeworms)

Tapeworms are morphodites constructed out of a scolex, a neck and strobila containing proglottids. Each proglottid has sexual organs of both genders. Adult parasites usually live inside the gut, some species prefer the gall bladder. Metacestodes settle inside other organs, too. For lizards, Pseudophyllidae is most interesting. These need two intermediate hosts for their development. As a consequence, they cannot be found in captive-bred chameleons, but in wild-caughts from time to time.

1.6 Nematodes (roundworms)

Heterakis ssp. unter dem Mikroskop

Heterakis ssp. in feces of Furcifer pardalis

Nematodes reproduce sexually. They have four larval stages (L1 to L4) and one preadult stage (L5) which matures to the adult parasite. Between L1 and L4, these nematodes shed four times. They have an impressing ability called “hypobiosis”, which means they can take a “rest” from reproduction or development somewhere in organ tissues. During this time, no eggs or larval stages can be found in the feces of the chameleon. But the parasites are still inside the chameleon’s body and may reproduce again when activated.

1.6.1 Rhabditis

Chameleons may become infected orally through infectious L3 from the feces of another chameleon, but that happens rarely. Usually, larvae migrate from the faeces and penetrate the skin of a not yet infected chameleon. From there, Rhabditis wanders via subcutaneous tissue into blood vessels, and from there with the blood flow to the lungs. In the lungs, they may cause slime growth, lung inflammation, and breathing difficulties. An infestation without symptoms is possible, too. They continue wandering along the throat, esophagus, and stomach to the small intestines, where the development ends and females begin to reproduce (with or without a male). Some larvae wander into tissue and organs, going into hypobiosis. Problems with Rhabditis mostly occur under poor hygiene and suboptimal husbandry, high temperatures, and high humidity. Chameleon eggs can even become infected during egg deposit.

1.6.2 Strongylidae

In Strongylidae, too, parasites migrate from the feces of an infected chameleon to penetrate the skin of another chameleon. Not all Strongylidae are sickening. These parasites live inside the chameleon’s gut, but also roam freely inside the coelomic cavity, lungs, nose, or subcutaneous tissue.

1.6.3 Spirurida

These nematodes live inside the stomach, often in the stomach walls. Since they need an arthropod (e.g. an insect) as an intermediate host which has to be eaten by the chameleon, occurrence in captivity is very low. Wild caughts may be affected from time to time.

Filariose Furcifer pardalis

Filaria under the skin of a young Furcifer pardalis in Madagaskar

1.6.4 Filarioidea

Mikrofilarie im Blutausstrich von Furcifer pardalis

Micro-filaria in a blood smear of Furcifer pardalis

Filariae may gain sizes from few millimeters to 8 cm length. They are transmitted by mosquitoes, so infection occurs only in wild-caught chameleons that have been imported like this. However, you cannot exclude with absolute safety that native mosquitoes in the new countries may transmit filariae. The adult parasites in the chameleon’s gut are called macro-filariae, the L1 in the blood is called micro-filariae. The blood parasites wander with the blood flow through different organ tissues and develop meanwhile. As adults, they migrate into the coelomic cavity, lungs, or in subcutaneous tissue. Under the skin, you can often see them as small, moving worms, that disappear when the skin is touched. Regularly, filariae do not lead to disease, but mass infestations may obstruct blood vessels and macro-filariae wandering can lead to peritoneal inflammations. In chameleons, especially Foleyella furcata is common in wild caughts. Treatment is rather difficult.

1.6.5 Ascaridida (maw worms)

Spulwürmer

Maw worms from the coelomic cavity of a panther chameleon

Infected chameleons excrete the first larval stage (L1 inside an egg) via feces, then the larvae develop to infectious L3 as parasite egg in the feces in a humid and warm environment (optimum is 22-25°C like in a terrarium). Other chameleons become infected with these parasite eggs. The infectious larvae hatch inside the small intestine and develop to a long, yellowish worm that may grow up to 12 cm. Maw worms wander outside the intestines, too. In lizards, Diaphanocephaloidea, Oswaldocruzia, Kalicephalus, Ophiotaenia, Proeocephalus, and Crepidobohyrium occur, in chameleons sometimes Heterakis additionally. These parasites may lead to bloody ulcers and obstipation in case of mass infestation, which can perforate the intestinal wall and even make parts of the gut necrotize (die-off). Some infiltrate the skin. Left untreated, a maw worm infestation can end deadly in chameleons soon. Unfortunately, ascarid eggs are extremely long-lasting and are thus often transmitted by humans unnoticed from cage to cage.

1.6.6 Oxyurida

Oxyurids are very common in captivity. They are very host specific and easy to treat by your vet. Chameleons become infected through oral intake of eggs containing larvae, from the feces of another chameleon. The infectious L3 hatches inside the gut and continues to develop there until the females begin to reproduce. Oxyurid eggs are excreted then via feces. Oxyurids are only sickening in case of severe infestations, they often remain undetected until a first fecal sample is examined. Oxyurid eggs remain infectious inside the cage over months, and keepers mostly unintentionally spread them from animal to animal by hand.

Oxyuris Furcifer pardalis

Oxyurid egg in feces of Furcifer pardalis

1.6.7 Capillaria (hairworms)

Chameleons become infected with hairworms by oral intake of eggs, of which infectious L1 hatch. The eggs only develop in high humidity and 20-24°C. In some species, earthworms take in the eggs, the L1 hatches and migrate through the worm’s tissue to develop an infectious stage. Capillaria live inside the chameleon’s small intestine and grow up to 8 cm in length. Eggs survive temperatures of -7°C and +12°C over two weeks.

1.7 Amoebas

Cysts from the feces of infected chameleons may infect other chameleons via oral intake. In the large intestine, the cysts develop to the so-called trophozoite and reproduce, some become cysts and leave the host. For chameleons, only the high infectious species Entamoeba invadens is of interest. These amoebas live inside the large intestine and penetrate the intestinal wall. Chameleons may get bloody gut inflammations that lead to emaciation and dehydration, partially the gut slowly necrotizes. Via blood, the amoebas can reach other organ tissues (mainly liver and kidneys) where they also cause inflammations, ulcers, and necrosis. The whole disease is called amoebiasis.

In immunocompetent animals, the infection may remain inside the gut and pass without symptoms, but stress may make the disease break out.  Since Entamoeba invadens develops at an optimum body temperature of 27-29°C, transmission to humans or other warm-blooded animals is not possible. Cysts survive at least eight days in soil and may be carried around by feeders or cage stuff. Disinfection with boiling water works well.

  1. Ectoparasites

2.1 Acari (mites and ticks)

Milben an Furcifer petteri

Mites in the axillary pits of a Furcifer petteri female in Amber Mountain

Mites and ticks belong to the arachnids and develop from an egg to a larva and a certain number of nymphs to the adult parasite. Larvae have three pairs of legs, adults have four. In some species, a nymph hatches from the egg without a larval stage. Between all stages, the parasites have to shed and feed on blood once.

2.1.1 Mites

Mites are sucking arachnids, that can be found around the eyes, in skin folds such as axillary pits and around the cloaca of chameleons. Most mites are 0,2-2 mm large and dark brown to reddish colored. You can see them with the naked eye or with magnifiers as small red dots on the skin. Severe infestations may lead to anemia (blood loss), itching may happen. In Madagascar, mites are rather common among chameleons in rainforests.

2.1.2 Ticks

Lizards mostly carry Ixodidae (hard-bodied ticks) that have a spine label made of chitin. Inside the first leg pair, the have Haller’s organs that are able to recognize potential hosts. Hard-bodied ticks develop from an egg via one larval and one nymph stage to the adult parasite. After one blood meal, the tick may survive a long hunger period. Males and larvae can spend their whole life without blood in some species. Full females can become 3 cm in length. Tick infestations may happen when cages are kept outside during warmer seasons in captivity, but it seems to occur almost not at all in reality.

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