Parasite Guide - Compiled by Alexis Jefferson
using Understanding Reptile Parasites 2nd Edition

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Before you dive into parasites and how to treat them, you must first look at the symbiotic relationship the host and the parasite has. There are three different types of relationships: commensalism, mutualism, and parasitism. Commensalism is where the parasite is given food and shelter but doesn't benefit nor harm the host. Mutualism is where both the host and the parasite are benefitted, such as the digestive bacteria in a human's stomach that feed on the foods we eat and also help break down the food we will digest. Parasitism is where the parasite feeds off of the host and may do them harm.

There are two different types of parasites, those that live outside the body (ectoparasites) and those that live inside the body (endoparasites). Examples of ectoparasites would be mites and ticks, and examples of endoparasites would be hookworms[1].

There are three major types of parasites that we should be worried about when it comes to our bearded dragons, protozoa, helminthes (worms), and arthropods. In the means of infection, there are two different lifestyles: direct and indirect[2]. Direct is when an animal can come into contact with its own feces and directly infest itself. Indirect is where there is an intermediary animal, such as a frog or rodent, that needs to ingest the eggs or larvae. Once the intermediary animal is infested, the beginning animal can eat it and become infected.

Signs of parasitism in reptiles can include but are not limited to:

  • Lethargy
  • Refusal to eat
  • Weight loss
  • Failure to grow
  • Regurgitation
  • Diarrhea
  • Blood in feces
  • Nonsolid, abnormally odorous feces

Medication Useful Against Nematodes
Nematodes include: pinworms, roundworms, hookworms, and whipworms

- Fenbendazole (Pancur): Fenbendazole is a very safe and stable dewormer that is hard to overdose your animal on. Doses up to 10,000 times still did not consistently kill mice. It has also been shown not to cause birth defects. When orally given, only a minimal portion of the fenbendazole is metabolized and the rest is excreted unchanged. This drug is best given in one big dose then again in a week.

- Levamisole (Ripercol L, Tramisol): Levamisole is very effective in getting rid of nematodes, and it is liked due to it being effective on nematodes also in the lungs. While it can be given subcutaneously, the window is very narrow. Toxicity shows in signs such as drooling, muscle tremors, head shaking, and respiratory distress. It's safer to give orally. Given once then again in two weeks. Should not be used in reptiles with weak livers or kidneys.

- Pyrantel pamoate (Strongid, Nemex): Substituted imidazothiazole derivative that is similar to Levamisole in the way it works. There should be no interaction with central nervous system (CNS) depressants, tranquilizers, insecticides, and muscle relaxers. Should not be used with Levamisol or organophosphates. After the first dose, repeat as needed at 10 to 14 day intervals, and weights dosages should be precise.

- Ivermectin (Ivomec, Double Impact): Liked because it can be given orally, topically, and via injection. Good to use against nematodes and arthropods, but it doesn't work on tapeworms or flukes. When giving by injection, avoid the CNS. Do not use on turtles/tortoises and take caution or avoid when using Ivermectin with skinks. Be precise with weight and dosages. Give a dose every 2 weeks until the fecal comes back clear. *Should be a last resort option. Ivomec isn't recommended for use in reptiles.

- Milbemycin (Interceptor): Milbemycin was created to be the Ivermectin for chelonians. It isn't the best antibiotic, but it works against mites, insects, and helminthes. It is only available as a pill but when crushed and suspended into propylene glycol, it becomes injectable. If using orally, it would be better to just use fenbendazole but milbemycin has the perk of also being injectable. More studies need to be done.

Drugs Useful Against Cestodes and Trematodes
Cestode parasites are commonly known as tapeworms and trematode parasites are commonly known as flukes.

- Praziquantel: Praziquantel is the only medication known to be effective against cestode and trematode parasites as well as being safe for reptiles. It can be given orally, sub-Q, and intramuscularly. Doses should be given every two weeks. Praziquantel should only be used on reptiles with great care with accurate weights for dosing.

Drugs Useful Against Protozoans
Protozoans include coccidia and cryptosporidia.

- Metronidazole (Flagyl): Metronidazole kills bacteria, trichomonads, and amoebae. It should not be used in weak or gravid animals, or specimens with liver dysfunctions. Vomiting, diarrhea, lethargy, and weakness note toxicity. Doses should always be measured accurately with weight and should only be given long enough to show a clean fecal. Excessive dosages caused signs of CNS damage. It may act as an appetite stimulant when given by balancing the bacteria flora and getting rid of protozoan flares.

- Sulfa Drugs (Albon, Bactrovet): Sulfadimethoxine (Albon), sulfamethoxine (Bactrovet), and trimethoprim sulfa are the choice drug to get rid of coccidia and it also works as an antibacterial. Sulfadimethoxine is suggested orally for a consecutive 5 days of doses then every 48 hours until the fecal is clean. Trimethoprim sulfa is suggested orally every 48 hours until the fecal comes back clean. The sulfa drugs are generally well tolerated as long as the reptile is well hydrated, and they shouldn't be used in animals with renal dysfunction. Loss of appetite has been observed while on the medication.

- Toltrazuril: "Liquid Toltrazuril is easier on the digest tract than Albon, which is why this was our choice in coccodiocide. The chmical structure is similar to Ponazuril, which is a metabolite of Toltrazuril. Toltrazuril is about 50% absorbed after oral administration. The highest concentrations are found in the liver where it is rapidly metabolized intro the sulfone derivative Ponazuril. Doses up to 10x have been found to have no adverse reactions in horse and 5x in poultry have been well tolerated. Toltrazuril has activity against many different types of coccidia at all stages." - LK Testing

Drugs Useful Against External Parasites
External Parasites include mites and ticks.

- Ivermectin: When used as a spray, mix 1 mL of a 1% solution to a quart of water. Ivermectin doesn't mix well with water so shake it well before each use, and store it in a dark place, as Ivermectin is light sensitive. It should last 30 days. Spray both the reptile and the habitat lightly every 3 to 5 days. The shortest recommended time is 8 weeks.

- Dichlorvos (No-Pest) Strips: Dichlorvos Strips are very efficient when it comes to killing pests. It is FDA approved safe for reptiles when used as directed. Be sure to keep the area well ventilated to avoid a build up of toxic vapors. Signs of toxicity include twitching arms and legs, ataxia, and seizures. Use a bubble-gum sized piece per 10 cubic feet, avoid reptile-to-strip contact, and make sure the area is well ventilated.

- Provent-A-Mite: When used as directed, Provent-a-mite is harmless to reptiles and kills mites and ticks. It bonds to surfaces so that it provides as longer lasting treatment than other products. It is EPA and USDA backed to be safe when used as directed. (

- Diluted Nix: Nix is used in humans to kill not only head lice, but also their eggs. Due to this, and its economical factor, many people turn to using diluted Nix. The suggested ratio is 1 part Nix to 68 parts distilled water. After the solution is mixed, make sure to keep it in the dark due to it being light sensitive. Remove the reptile and spray it liberally with the solution then clean their enclosure and spray it all down. Clean the enclosure daily when you notice dead mites on the preferably paper towel substrate. Repeat two more times in 5-7 days (

** Probiotics should be used whenever medicine is given as to help replenish the gut flora. **

Going deeper into specific parasites...

Roundworms (Ophiascaris spp., Polydelphis spp., Hexametra spp., Amplicaecum spp.):
Roundworms have an indirect life cycle, which as said above, means there must be an intermediate host of a mouse, frog, fish, etc. before it can be passed to your reptile. Moderate loads of roundworms can be tolerated but the GI tract along with other ducts can become impacted by a heavy load.
Suggested treatment: fenbendazole 50-100 mg/kg PO rep in 2-3 wks OR 100 mg/kg PO rep in 2 wks OR 25 mg/kg PO rep q 2 d for 3 wks.

Hookworms (Oswalsocruzia spp.):
Hookworms have a direct life cycle so much caution should be taken to ensure a clean habitat. They attach themselves into the lining of the intestines and can be found anywhere from the esophagus to the rectum. They feed on blood.
- Suggested treatment: fenbendazole: 50-100 mg/kg PO rep q 2 wks 1x OR 25 mg/kg PO rep q 2 wks until 4 negative fecals obtained.

Pinworms (Oxyurus spp.):
Pinworms are common in many lizards and turtles, and they have a direct life cycle. Caution should be taken to ensure a clean habitat. Other than the parasitism, they cause little other disease. Heavy loads are known to cause rectal prolapse.
Suggested treatment: fenbendazole 100 mg/kg given q 2 wks until clean fecal is obtained.

Entamoeba invadens:
E. invadens can cause a high death rate in snakes and a lesser rate in lizards, but it causes chronic disease and should be treated promptly. It is acquired by eating or drinking cyst-contaminated water. Having the hot side of the tank at 95F can help inhibit the amoeba's growth.
Suggested treatment: Metronidazole given orally for 3 days then every 48 hours for a total of 5-10 total doses.

Flagellates (Leptomonas spp., Hexamastix spp., Hypotrichomonas spp., Trichomonas spp., Tetratrichomonas spp., Trichrichomonas spp.):
There are many species of flagellates found in snakes and lizards, and many are generally are seen as normal gut flora. However, things such as stress and incorrect temperatures can cause them to explode in number. It is acquired by eating or drinking cyst-contaminated water. They are diagnosed by direct smears.
Suggested treatment: metronidazole 25-50 mg/kg PO, rep in 3-4 days if needed

Coccidia (Eimeria, Isospora, Caryospora, Cryptosporidium species):
Coccidians are often acquired by exposure to contaminated food, water, and environment. Stress and poor care can cause blooms, and due to a direct life cycle, it is imperative to keep a clean habitat. Isospora amphibohtri is the parasite in bearded dragons. They destroy the epithelial cells of the intestine, biliary system, and/or kidneys, which can cause fibrosis and ulcers. Suggested Sulfadimethoxine treatment: give orally for 3-5 days consecutively then every 48 hours until parasite is eliminated.
Suggested treatment: toltrazuril 20 mg/kg PO rep q wk 1x for 2 wks, 3 if needed
** Sulfa drugs should not be given to emaciated or dehydrated dragons due to the prospect of renal harm.

Cestodes (Tapeworms):
To get tapeworms, your reptile must eat an intermediate host, meaning it's an indirect lifestyle. Signs of a cestode infestation are malnutrition, inflammation, and obstruction of the GI tract. Suggested treatment: praziquantel orally or via injection (sub-Q or IM). Give the next dose in 2 weeks.

Trematodes (flukes):
Monogenetic trematodes have a direct life cycle and digenetic trematodes have an indirect life cycle. Flukes can live in multiple different animals, monogenetic favoring fresh water fish and digenetic favoring snakes, in multiple different organs. Adult flukes in the mouth of snakes can be removed by cleaning the mouth with a q-tip.
Suggested treatment: one dose of praziquantel rep in 2 weeks.

Enclosure Clean Up
Hospital Enclosure page is here : Setting up a hospital enclosure

- One of the most important steps in keeping a habitat/enclosure clean is to remove stool as soon as possible. The longer the stool sits, the more time the direct life cycle parasites have a chance at getting back into your reptile.
- Make sure to clean dirty water as soon as it is noticed and if it isn't dirtied, clean it once every 24 hours.
- Steam cleaning with steam that gets at least 165F is a good, nonchemical way of killing many parasites.
- Ammonia solution: 1 part ammonia to 10 parts water
- Bleach solution: 1 part bleach to 10 parts water

How to Kill:
- Pinworms: Steam, bleach solution
- Roundworms: steam or high heat from a blow torch, chemicals do not work
- Hookworms: bleach, heat, freezing, direct sunlight (eggs)
- Tapeworms: it isn't certain whether bleach kills tapeworms, but it helps loosen them and makes them easier to wash away, they can die at 14F or lower
- Coccidia: steam, heat, freezing, ammonia solution

* Never mix bleach and ammonia
* Don't apply heat to cold glass- it may shatter
* Laminated materials may lose the lamination when exposed to extreme heat
* Materials that could melt should be cleaned with chemicals

How to read dosages:
rep: repeat
q: every
wks: weeks
___x: number of times
PO: per os/by mouth

Ex.: 50-100 mg/kg PO rep q 2 wks 1x = 50-100 mg/kg repeat every 2 weeks 1 time

** This is not a substitute for vet care. LK Testing takes no liability of any potential harm done by self-prescriptions. **

** The vast majority of this was put together using Klingenberg's Understanding Reptile Parasites 2nd Edition. Credit goes to him unless otherwise noted. If you are interested in reading it, it is available on multiple websites including Amazon. **


Klingenberg, Roger. (2007). Understanding Reptile Parasites: From the Experts at Advanced Vivarium Systems 2nd Edition. Advanced Vivarium Systems (cleaning and toltrazuril) (Nix mite killer) (dosages)

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