How to detect betta fish internal parasites?

In this post, we will answer the question “How to detect betta fish internal parasites?”. We will also discuss the most common betta fish diseases caused by internal parasites.

How to detect betta fish internal parasites?

There are several diseases caused by internal parasites in betta fish, these parasites can be viruses, fungi, or bacteria. Detecting the internal parasites will require observing and analysing the symptoms your betta fish has developed. The main diseases are:

–       Intestinal parasites

–       Ich or White Spot Disease

–       Oodinosis or Velvet Disease

–       Columnaris

How do you know if a betta fish is sick?

Pets, unlike humans, do not speak and are unable to express themselves when they are ill. In the case of fish, the issue is considerably more complicated than it already is. As a result, it might be difficult for us to determine how to care for a sick betta fish when it happens.

Their organism, which belongs to a completely different class than ours, manifests problems in a very different way, with no fever, tremors, or whimpers.

In general, changes in appearance can indicate that something is wrong with the betta fish. It may also alter its behavior in response to the magnitude of the issue encountered.

Top indicators that your betta fish is sick:

–       Fading colour; 

–       Corroded fins; 

–       Spots on the body; 

–       Wounds all over the body; 

–       Changes in behaviour (especially lethargy); 

–       Sick betta fish refuses to eat; 

–       Changes in swimming pattern; 

–       Fish scratching on surfaces. 

Other changes, such as difficulty breathing (in this case, the fish can go to the surface of the water), should serve as a warning in addition to these symptoms. Observe and analyze the health of your betta, as well as the overall quality of the environment in which it lives.

The most common betta fish diseases 

The health of all species of fish depends on keeping the aquarium clean and maintaining proper water conditions. Even yet, it is likely that the betta fish will become unwell at some point as a result of some negligence or even stress.

Knowing how to recognize some of the most common diseases at this point makes reporting the problem to a specialist and taking appropriate measures much easier. Among the diseases that affect betta fish. 

Common betta fish diseases caused by internal parasites

Parasites are organisms that dwell close to others and rob them of their means of living, usually by hurting the host organism, a process known as parasitism.

Intestinal parasites

These parasites feed on any food that the Betta fish consumes, causing them to become drowsy and, in a sense, malnourished. To be successful, an owner must recognize this early and treat the Betta fish accordingly. 


Parasites, like brown worms, commonly enter the tank through food. In Betta fish, intestinal parasites are far less common than external parasites. 


Changes in behaviour, drowsiness, and weight loss despite eating normally Intestinal parasites can be passed from one Betta to the next. 


Replace the tank’s water and clean any objects that will be returned to it. One teaspoon of aquarium salt should be added to the new water. If your fish’s situation does not progress after this, you will need to purchase antibiotics from a specialized aquarium store.

White Spot Disease (Ich) 

Betta fish are susceptible to one of the most frequent infections. Although healthy Betta fish have inherent resilience to ich, it is found in the majority of fish tanks and aquariums. 


ichthyopthirius) is a parasite that feeds on the Betta, and it is the cause of the sickness. Upon removal, it multiplies on the tank’s bottom where it feeds on other Betta fish, which causes the parasite population to explode. Ich can be spread by eating frozen living food. 


Small white specks on the body and fins, as well as the eyes in some cases, clamped fins, rubbing on decorations and the tank’s side, and a decrease in activity. 


To cure the entire tank, use formalin or malachite green. If you have the option, clean your tank and boost the temperature to 85 degrees Fahrenheit/up to 30 degrees Celsius. Because these parasites can’t stand the heat, your fish will recover completely in a matter of days. 

Velvet Disease or Oodinosis 

Velvet is a parasite that looks like velvet and is very frequent among Betta fish. 


The sickness is caused by parasites (adult Oodinium) that adhere themselves to the Betta fish and infect it. While feeding on the Betta’s skin cells, the parasites form a hard shell around themselves that can last up to a week. After detaching themselves from the Betta, they reproduce on the bottom of the fish tank and then reattach themselves in increasing numbers to the Bettas in the tank.


Betta’s fins and body may become clamped, and the fish may scratch against the tank wall, resulting in a loss of appetite (this can be more easily seen with the use of a torch). Golden/copper-colored dust may appear on your Betta’s body and fins (this can be more easily seen with the use of a torch).


To cure a Betta with velvet, turn off the tank lights and boost the water temperature. In these settings, parasites are unable to survive. After that, apply the commercial malachite green treatment. Because velvet is so contagious, it’s critical to treat every one of the fish in that tank. It is important to thoroughly clean the tank and to refill it with fresh, clean water.


Fish that have been troubled by another sickness or stress in the past, such as a poor diet or an inappropriate habitat, are more likely to contract Columnaris, commonly known as mouth fungus. Maintain great water quality and sterilize all apparatus before it enters the tank in order to avoid contracting this illness. In order to prevent the spread of Columnaris, affected Betta fish must be taken from the aquarium and incubated separately.

This disease can be internal or exterior, although it is most usually encountered in Betta fish. There are two types of this infection: slow and fast, and which one your Betta has will determine how likely it is to recover from the illness. Caused by Saprolegnia species.

The symptoms include a cotton-like growth around Betta’s mouth as well as white spots on the mouth and fins of the fish. The fins of the Betta will tear as the virus spreads. Internal infections often have no symptoms at all, making it difficult to diagnose until it’s too late. 


You must first eradicate the bacterial illness from the entire tank before treating Columnaris. This involves changing the water, vacuuming the substrate, and applying aquarium salt. After cleaning the tank, use an antibiotic or copper sulphate to treat it. 

The Best Ways to Keep Your Betta Fish Happy and Healthy 

Following the diagnosis and treatment of an illness in your Betta fish, there are a few things you can do on a daily basis to keep your fish happy and healthy. Preventative measures are always preferable than curative measures while caring for a Betta fish, which is why the following guidelines should be followed: 

  • It’s important to clean your tank or fish bowl on a regular basis. 
  • You should also check the pH levels of the water. 
  • You should quarantine any new fish you bring home. 
  • You should add aquarium salt. 
  • Dead fish should be removed from a tank as soon as possible to ensure the safety of the other fish in the aquarium.


In this post, we answered the question “How to detect betta fish internal parasites?”. We also discussed the most common betta fish diseases caused by internal parasites.

If you have any questions or concerns, please let us know in the comments section below!

Frequently Asked Questions (FAQs): How to detect betta fish internal parasites?

What is the best way to tell whether my betta fish has a bacterial infection? 

When Bettas exhibit indications of bacterial illness, such as frayed or torn fins, red sores, or slimy areas, use this medication to treat them effectively. 9 drops per pint of aquarium or bowl water, or 18 drops per quart of aquarium water.

Is aquarium salt effective in treating internal parasites? 

Osmosis removes the saltiness of aquarium water from bacteria, fungi, and parasites as the process seeks to equalize the salt content on both sides of its membrane or skin. Aquarium salt can kill numerous diseases and parasites in fish through osmosis.

How long can fish survive with parasites within their bodies?

This condition is often confused with ich, but velvety fish appear to be sprinkled with gold dust, hence the colloquial name “gold dust disease”. This parasite travels from fish to fish by the use of a flagellated spore and can remain on the fish for at least 24 hours, if not longer, after being introduced (up to several days).

What causes internal parasites in fish?

When fish feed on intermediary hosts, parasites infect them. Marine animals such as seals and dolphins, as well as fish-eating birds such as cormorants and seagulls, are the definitive hosts for fish roundworms. In their feces, these hosts deposit eggs, which hatch into larvae in the water.

Do betta fish feel pain?

Fish have the right anatomical structure to detect pain signals, they create the same natural chemical relievers as mammals, and they actively avoid unpleasant stimuli. They also go through feelings that we humans may relate to.


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