Nematode parasites are a risk that a lot of new tarantula owners are not aware of or prepared for. Many tarantulas owners get into the hobby because tarantulas are a fascinating, low maintenance pet. Over their lifetime, a tarantula will cost you far less than a cat or a dog and are less likely to have health conditions or sickness. However, just because there aren’t tarantula veterinarians in every town doesn’t mean that there are not health risks. If you don’t educate yourself on tarantula first aid or tarantula illnesses to look out for, you could miss a major warning sign that something isn’t right with your tarantula.

Tarantulas can get parasites just like any other living creature, and the nematode is a common one for Ts. As per giantspiders.com:

Nematode worms are microscopic non-segmented worms that occur naturally in soil all around the world. Most are harmless to your tarantula but there are some species (Steinernema sp.) that are major parasites in invertebrates. They transmit bacteria that is lethal to it’s host and for this reason they are often used for biological insect pest control. Wild caught spiders are sometimes imported carrying these worms and if not properly dealt with, they can spread throughout a collection with devastating effects. Nematode worms penetrate their host through any small opening (usually via the book lungs or the anus. The mouth has a very efficient filter system that prevents the worms entering here). They then spread throughout the entire spider to eventually emerge through the mouth. Up until the final stages of infection, the spiders behaviour is quite normal and, unfortunately, when the symptoms are noticed, it is usually too late. Although devastating when present, nematode worms are relatively rare in collections and by taking the right precautions and procedures, you can at least limit the amount of damage they do.

Here’s a great video that explains more and provides a visual of what this looks like:

The main giveaway that a tarantula who has a nematode parasite, they’ll have white worms coming from their mouth area. However, there is another way you can test this as well:

A quick test is to gently shake the spiders’ container. Under normal circumstances, the spider will steady itself with all the legs and this includes placing the palps on the floor also. Infected spiders won’t do this. You can also try feeding, as affected spiders cannot attack prey. If your spider accepts prey, chances are worms aren’t present. I

Other warning signs might be the following:

restlessness, spinning unusual amounts of silk, spending long periods around the water dish, any unusual sweet odour coming from the container, a very wet sternum caused by the spider drooling (not to be confused with normal cleaning behaviour) and, most importantly, a white sticky mass around the mouth and holding the palps permanently under the chelicerae

What exactly causes a nematode parasite is uncertain, but it is thought that they enter through a tarantula’s book lungs when they’re young and once mature, then exit through the mouth. Some believe this might happen thanks to an infected food source, substrate issues, or from being transmitted from infected wild caught tarantulas.

So is this fatal?

Not necessarily. While more research needs to be done, some tarantula owners claim they have cured the nematode parasite in their spider. Arachnopheon on Arachnoboards.com shared their own experience and stated they used two drugs to help their tarantula. They said, “antibiotic (Cefotaxime – eh.. in powder 1g – put in 10ml of pure H2O for injections) and second is antinematode Pyrantel.” Some of those drugs may not be over the counter where you live and you may need to get a prescription. Here’s what they wrote about their experience:

How to use:
First of all – clean up the mess (if there it is) near the tarantula mouth with warm water. After this take Cefotaxime 1g and dilute it with 10ml of Injection water, use it on the tarantula mouth and chelicere and where is nematodes, but dont try to push it inside tarantula’s mouth. After this one is dry – use Pyrantel with ear-cleaning-stick around tarantula’s mouth and chelicerae, but dont put so much. Repeat this 3-5 days and remember to clean the cage and waterdish everytime after procedure.

However, there is no guarantee. Sometimes if it’s not caught soon enough, nematodes can cause severe damage to a tarantula’s stomach and intestines. They can cause too much bacteria, which makes them unable to respond positively to the drugs.

If you believe one of your tarantulas has been infected with nematode worms, you should quarantine it away from the rest of your collection just to be safe. Guy Tansley of bugsnstuff/giantspiders.com also recommends another method that may work:

1. Place the spider in a tub tilted to one side (include a small amount of water) inside a polystyrene box with a heat mat attached to a thermostat. Raise the temperature to over 36 degrees Celsius and leave for 5 days, changing the water and cleaning the tub daily. It is said that nematode worms become inactive below 12 degrees Celsius and die with the temp is above 35 degrees Celsius. All species of tarantulas may not be able to tolerate high temperatures like this, so use caution.
2. After 5 days the worms should die and the spider’s mouth should be clear. Unfortunately most tarantulas treated this way still eventually die by the time the worms start to exit the mouth due to internal damage that is irreversible. However, it’s still worth a try if this is your only hope.

Preventative measures

You can make it less likely for your tarantula to get nematode parasites by maintaining regular spot cleaning.

We obviously must do more research about this, but this is what’s out there right now. If you’d like to learn more about nematodes, here’s a great writeup of a study. To learn more about tarantula care and tarantula first aid/illnesses, check out my tarantula guide!