How to Treat Camallanus Red Worms in Aquarium Fish

Fish diseases can be notoriously hard to diagnose, but one of the more easily recognizable illnesses is an internal parasite called the camallanus red worm. Multiple species of roundworms and nematodes that belong to the Camallanus genus can infect aquarium fish. They feed by attaching themselves to the intestinal walls. The immune system can be affected by stress factors like poor water quality and aggression from tank owners. Worms can cause severe damage or even death.

Red Worms on Fish

For a short time, the fish can look pretty normal during the early stages. In the later stages of the disease, you might notice that your fish become slower, the adult fish may not be producing as often, and eventually you will lose a few fish each month. A loss of appetite was also reported by hobbyists.

If you see one or more red worms emerge from the fish’s vent, this is an indicator that it is serious. It may look like a small cluster of scarlet threads that extend about 1/4 to 1/2 inch (6.6-3.3 cm). At this stage, the disease may be very advanced and fish could appear unusually thin due to the worms taking all the nutrients. Secondary infections can occur when worms block the intestines.

Camallanus Red Worms are often more obvious in small livebearers. They take longer for the worms to reproduce and become large enough to be able eat larger fish like angelfish.

Guppy with camallanus Worm protruding from anal vent

What Causes Camallanus Red Worms?

Infected fish can pass the worm larvae to other fish in the aquarium. The larvae can then be eaten by tiny crustaceans, such as cyclops, if the fish is introduced. Healthy fish will eat the infected crustaceans. The larvae become adults and can reproduce in the fish’s body. Some species do not require an intermediate host. In fact, fish can be infected simply by eating fish feces containing larvae. Either way, the disease is fairly contagious, so adding plants, gravel, or equipment from an infected tank to a healthy tank can cause cross contamination that also spreads the parasite.

How can I rid myself of Camallanus Worms

Fritz Expel P, which contains levamsole and targets roundworms such camallanus, can be used to treat the fish. The medication paralyzes adult worms and allows them to be expelled by an aquarium siphon. Follow the manufacturer’s instructions on the box by using 1 packet of Expel-P per 10 gallons (38 L) of water. After 24 hours, perform a 25% water change to remove the excreted parasites. Since levamisole does not affect unhatched eggs, wait two weeks after the initial treatment and then dose the tank again with Expel-P to deal with any remaining worms.

Fritz Expel-P medication for parasitic diseases

Some articles recommend putting the dewormer in food and feeding it to the fish, but we like to treat the water of the whole tank because sometimes fish lose their appetites and you cannot always control how much medication each fish eats. Consider using broad-spectrum or antifungal treatment if secondary infections are present in your fish.

The key to recovery is not medication. It’s about lowering stress levels in the aquarium and hospital tanks. High-quality foods are important to aid in their weight gain and faster expulsion of worms. For paralyzed parasites to be removed, ensure that the water quality is high. You can also disinfect siphons and other equipment that is shared to prevent the spread of disease.

Dosing an Expel-P packet

How Do I Prevent Camallanus Worms?

It is recommended that all new fish be quarantined for a period of time to observe their behavior, health, appetite, and general health before you add them to your display tanks. The trio of quarantine medications helps to prevent most bacterial, fungal and parasitic infections. However, if you are concerned about camallanusworms, Expel-P can be used as an additional treatment. Red worms can be tolerated by most fish for some time before becoming problematic. Keep the tank clean and provide fresh food. Keep the quarantine area separate, wash your hands after touching it, and use separate siphons and nets for fish in quarantine.

Check out our articles for more information about fish diseases. Learn how to diagnose, treat, and prevent the most common ailments.

Attributions 190729 Guppy 1 by BlueBreezeWiki. (CC BY -SA 3.0).