Worms or Parasites That Can Get Your Reptile Sick

Potentially Harmful Amoebas, Protozoans, Flagellates, and Worms

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Reptiles, like horses or other pets, may have worms or intestinal parasites that may not cause any issues and keep the gut healthy.

But when a reptile is sick, such as is not eating well, is losing weight, or is not defecating normally, there may be too many of these normal parasites for your reptile's system. When the worms and your reptile seem to have a peaceful relationship, then there is no need for alarm.

If your reptile is found to have intestinal parasites and it starts acting sick or having problems, then you will need to get your pet to an exotic animal veterinarian to see what's going on and if intestinal parasites are the problem.

How Do I Know If My Reptile Has Worms?

You may see worms passing in your reptile's stool but, more often than not, you will not see any kind of worm. Many intestinal parasites that people commonly refer to as "worms" aren't worms at all. Amoebas, protozoa, flagellates, and other kinds of microscopic parasites are more commonly seen under a microscope than actual worms.

The only way to know for sure what kind of parasites your reptile has is to look at a sample of their stool under a microscope. Your exotic animal vet will perform a fecal stain, direct smear, or fecal flotation (or all three) to find out if your pet has a parasite problem. If these tests come back positive, then the vet may prescribe appropriate dewormers or other medications to alleviate the infestation.

Even if you think your pet is fine, at least once a year you should take your reptile to the vet to have it looked at, this should include a fecal check.

Types of Intestinal Parasites

There is a long list of possible kinds of parasite your reptile can have or be infected with. Some cause a problem (in larger quantities) while others can be completely normal for your pet to have (in smaller quantities). Your reptile should only be treated for the parasites if it exhibits health distress or if the parasite populates outside of the ordinary amount.


The two most common ways that your reptile can get this infection is if you offer water that is contaminated with this protozoan, or if you feed wild caught prey items that have Cryptosporidium. Cryptosporidiosis was previously considered a zoonotic disease; however, it now appears that some, but not all, of the species commonly found in reptiles do not affect mammals.

It causes terrible diarrhea and weight loss, as do most intestinal parasites. It does not produce a worm that you will see in the feces. Infection with this type of coccidia protozoan does not offer a good outcome for most pet reptiles and typically cannot be seen under a normal microscope. If you or your vet suspects a cryptosporidium infection, a special test should be performed to check for it.


Also known as the threadworm or seatworm, this is a common kind of nematode worm that you cannot see with the naked eye. It can be completely normal for your reptile to have pinworms since they typically contract them from eating infected mice or insects. Your vet may not treat your reptile for a pinworm infection unless it is causing a problem for your pet, such as a decrease in appetite or a fecal obstruction. People can also get these worms passed on to them through reptiles, so it is always important to wash your hands after handling a reptile.


​This is another microscopic parasite that is transmitted through contaminated drinking water or contaminated food. It will cause problems such as vomiting, diarrhea, lethargy, and even bloody stools. It can only be seen microscopically.


A very common parasite in pet reptiles, this protozoan does not always show up in fecal samples. It does not always shed eggs to visualize, so it can be difficult to diagnose but can be safe for your reptile to have in small numbers (unless it is Cryptosporidium, which is more serious). A stressful situation may cause it to overpopulate and cause an issue for your pet.


These worms can actually be visualized in the feces of your reptile. They look like long spaghetti-like worms and are easily treated by your exotics vet.


You will not see these worms in your reptile's feces, but they usually cause bloody stools due to the nature of the parasite. These worms "hook" onto the lining of your reptile's intestines causing the blood you see in the stools. They are typically easily treated.


These little worms look like pieces of rice. They may be connected to form a worm or, more commonly, you may just see the rice-like segments of the worm in the stool. Like most other parasites they can cause weight loss.


Parasites like giardia are a kind of flagellate. Reptiles can harbor many kinds of flagellates, most of which are normal in small amounts. But if your reptile is showing any symptoms of a parasitic infection, your vet may prescribe a dewormer.

Other Intestinal Illnesses

Other than parasites, your pet reptile can get other intestinal illnesses caused by bacteria like Salmonella. You should always wash your hands after handling any reptile.

Article Sources
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  1. Parasitic Diseases of Reptiles. Merck Veterinary Manual.

  2. Cervone, Mario et al. Internal And External Parasitic Infections Of Pet Reptiles In ItalyJournal Of Herpetological Medicine And Surgery, vol 26, no. 3-4, 2016, p. 122. Association Of Reptilian And Amphibian Veterinarians (ARAV), doi:10.5818/1529-9651-26.3-4.122

  3. Reptiles and Amphibians. Centers for Disease Control and Prevention.