Nematodes in Lizards

Nematodes in Lizards - Symptoms, Causes, Diagnosis, Treatment, Recovery, Management, Cost
Nematodes in Lizards - Symptoms, Causes, Diagnosis, Treatment, Recovery, Management, Cost

What are Nematodes?

The nematode is one of the most often reported parasites in lizards and has been found on over 500 different types and forms of reptile. These parasites can infect the bloodstream, lungs, liver, trachea, esophagus, large and small intestine, stomach, and mouth. In the wild, it is quite normal for a lizard of any kind to have nematodes, but these parasites can be a problem for captive lizards (like your pet). In fact, some types of nematode can be fatal if not treated. Nematodes are roundworms that most often found in the digestive tract of lizards where they are able to feed off whatever your pet eats. There are a few that prefer the lungs or outer body cavity, but the majority are concentrated in the gastrointestinal system.

The most common nematodes in lizards are Kalicephalus, Parapharyngodon, Physaloptera, Physalopteroides venancioi, Rhabdias, Spauligodon oxkutzcabiensis, Dracunculus, and Strongyluris. However, there are hundreds of nematodes that can affect lizards and other reptiles. These parasites are able to reproduce and lay their eggs in the lizard’s body and when the eggs hatch, the larvae will feed off the protein and other nutrients they find in the digestive system. A large infestation can quickly overtake your lizard’s system and may be fatal without treatment. If your lizard is not acting normally, has no appetite, and just looks ill, you should take your pet to a veterinary professional right away.

Symptoms of Nematodes in Lizards

There are different symptoms depending on which type and what area of the body they inhabit. Some of these include:

Kalicephalus, Parapharyngodon, Physaloptera, Physalopteroides venancioi, Rhabdias, Spauligodon oxkutzcabiensis

  • Nausea
  • Vomiting (regurgitating food and possibly worms or larvae)
  • Diarrhea
  • Ulcerative lesions
  • Depression
  • Fatigue


  • Dermal lesions anywhere on the body
  • Depression
  • Not eating
  • Weakness
  • Sudden death


  • Agitation
  • Breathing abnormally
  • Lethargy
  • Depression
  • Diarrhea


There are many types of nematode that have been known to infect lizards such as:

  • Dracunculus is a spirurid worm that attacks the peritoneum and blood vessels
  • Kalicephalus is a hookworm that infects the upper gastrointestinal tract and causes eroding lesions
  • Parapharyngodon are roundworms that infect the stomach of the lizard
  • Physaloptera is a stomach worm commonly found in the large intestine
  • Physalopteroides venancioi infects the stomach.
  • Rhabdias can be found in the lizard’s lungs and stomach.
  • Spauligodon oxkutzcabiensis inhabits the stomach and intestines.
  • Strongyluris larvae incubate in the lungs and the adults infest the large intestine.


Causes of Nematodes in Lizards

  • The cause of nematodes in lizards is usually due to:
  • Eating insects already infested with nematodes
  • Large groups of lizards living in one environment
  • Access through a lesion in the skin
  • Through the vent
  • Unsanitary conditions


Diagnosis of Nematodes in Lizards

Diagnosing your lizard for nematodes includes a complete physical examination including vital signs, body condition, and general health. The veterinarian may decide to get radiographs (x-rays) or an ultrasound to determine the area and severity of the suspected infestation. Laboratory testing will also be needed such as a blood count and chemistry panel, urinalysis, and a liver enzyme culture. Additionally, a stool sample is taken and can be checked with fecal floatation (eggs do not float), sedimentation culture, and microscopic analyzation of a fecal smear.  If necessary, a lung, cloacal, or gastric wash can give the veterinarian an idea of which nematode is responsible.



Treatment of Nematodes in Lizards

The treatments for nematodes vary depending on which type your lizard has.

Treating Kalicephalus, Parapharyngodon, Physaloptera, Physalopteroides venancioi, Rhabdias, and Spauligodon oxkutzcabiensis

These can all be treated by Fenbendazole, which is the safest member of the benzimidazole group of anthelmintics. This drug sterilizes and kills the adult worm and the eggs. It works by slowing the glucose production in the nematodes until they are dead. Fenbendazole is considered safe for reptiles and is not metabolized or absorbed into their body. Rather, it is excreted without change. Other similar medications that may be used include Mebendazole, Pyrantel pamoate, and Ivermectin.

Treating Strongyluris

Levamisole is an imidazothiazole anthelmintic proven to be extremely effective in treating nematodes. This is one of the only drugs that kills nematodes in the intestinal tract and lungs from being injected subcutaneously. This drug stops the nematode’s body from metabolizing protein and paralyzes the parasite so it is expelled in the feces while still alive. This must be done by a veterinary professional because the dosage has to be exact due to the side effects. If too much is given, your lizard can die from respiratory failure.

Treatment for Dracunculus

The treatment for this nematode is to increase the temperature of your snake’s environment for 24-48 hours to 97 to 98 degrees. Some reptiles may not be able to handle this temperature so you have to talk to your veterinarian before treating.  



Worried about the cost of Nematodes In Lizards treatment?

Pet Insurance covers the cost of many common pet health conditions. Prepare for the unexpected by getting a quote from top pet insurance providers.

Recovery of Nematodes in Lizards

Diagnosis is good as long as you get professional treatment for your lizard. Without treatment, a major infestation can be fatal. To prevent this from happening again, you have to be sure to treat all of your reptiles, the cage and everything in it, and get your lizard’s food from a reputable dealer or your veterinarian.



Nematodes Questions and Advice from Veterinary Professionals

Need pet insurance?
Need pet insurance?

Learn more in the Wag! app

Five starsFive starsFive starsFive starsFive stars

43k+ reviews


© 2022 Wag Labs, Inc. All rights reserved.