Catfish are an important food source in many parts of the world. Despite this, they are also susceptible to several diseases, which can decimate local populations and reduce the availability of this important food source.
In fish production, bacteria, fungi, and protozoan parasites are the main disease-causing microorganism. Overfeeding, high stocking densities, and other organic loads promote the growth of harmful diseases in catfish.
It is often far more difficult to treat catfish diseases as they might have gotten worse when appropriate care can even be arranged. However, in this blog post, we’ll look at some of the diseases and treatments for catfish. Let’s cut to the chase!
How To Know If Your Fish Is Sick
This is rather simple. Dead or dying creatures are the most visible indicator of sick fish. However, a keen observer can typically detect illness in fish before they begin to die since sick fish may exhibit lethargic behavior and even stop feeding. If fed at regular intervals, healthy fish should consume food quickly. Pond fish shouldn’t be visible until they are actively feeding.
Something might be awry if fish are seen rubbing against objects, gasping at the surface, or hanging listlessly in shallow water. These odd behaviors show that the fish are not feeling well or are bothered by something.
Diseases and Treatments For Catfish
It is important to act on every health concern based on the methods that are practical and scientifically supported to overcome losses caused by infectious diseases. Below are some of the common conditions and treatments for catfish.
1. Proliferative Gill Diseases (PDG)
Fish gill infections are a serious health issue that can affect fish populations. Proliferative gill diseases (PGD) are a type of gill disease characterized by the overgrowth of tissue in the gills. Numerous physiological and environmental stressors can lead to PGD.
Symptoms of the infection in fish include increased mucus production, gill redness and inflammation, and ulceration. In extreme circumstances, the fish may go into a respiratory crisis and pass away.
Proliferative gill disease can result in large financial losses for fish farmers.
To lessen mortality, it is advised to frequently pump water across a level from an older, healthy pond into a pond that has PGD. Additionally, PGD-infected catfish should be taken out of the infected pond for a swift recovery.
It is widely known that once a PGD outbreak is over, the illness usually doesn’t return to that pond for the rest of that season even though there are no effective, proven treatments.
2. The Channel Catfish Virus (CCVD)
CCVD is a severe catfish disease that can have a significant financial impact on catfish farms. It is mainly caused by an Ictaluri herpes virus 1, which spreads swiftly and kills a lot of young catfish and fry.
An infected fish will exhibit obvious symptoms like bleeding fins, pop eyes (exophthalmos), and bloated abdomens (ascites). The virus, usually undetectable by culture during the latent stage, is secretly carried by fish that do not succumb easily to CCVD.
Incubating eggs and fry in a separate housing from carrier communities is one control method.
It is also advisable to avoid handling young animals under stressful conditions during warm months.
3. Brown Blood Disease
Brown blood disease, which gets its name from the brown discoloration of the fish’s blood, causes fish to bleed to death internally. The disease has been linked to several factors, including climate change and the use of certain chemicals.
An overabundance of ammonia in ponds causes ammonia-eating bacteria to go into a feeding frenzy and produce the waste product nitrite. Nitrite can penetrate catfish gills at high concentrations, which causes the oxidation of hemoglobin in the red blood cells.
As a result, methemoglobin, the resultant substance, cannot carry oxygen and cause suffocation. Depending on the saturation level, the blood of infected catfish may be reddish or deep brown in color.
The most apparent preventive treatment is minimizing or lowering the amount of nitrogen introduced into the system by decreasing feeding rates because this is a nitrogen-related issue.
However, most farmers do not view long-term feed reduction as a viable choice in a contemporary intensive pond or closed-system fish production with high densities and rapid grow-out.
Fortunately, although elevated nitrite levels may frequently not be avoided, their consequences can be safely and effectively reduced or eliminated.
Brown blood sickness is “treated” with sodium chloride (common salt; NaCl). It is also possible to utilize calcium chloride; however, it is usually more expensive. The chloride component of salt competes with nitrite for intestinal absorption.
4. Columnaris Diseases
Columnaris disease is a bacterial infection that affects freshwater fish. This disease is caused by the bacterium Flavobacterium Columnare, which is usually found in surface water.
It occurs mostly in the summer when water temperatures range from 77 to 90 degrees Fahrenheit. The bacteria can infect fish through open wounds and spread quickly when they adhere to the gill surfaces, resulting in necrosis.
Skin lesions and gills that are yellow-brown in color are typical signs. Columnaris disease can be fatal to fish, and fish keepers need to be aware of the symptoms of the disease. Centralized ulcers may also appear in advanced lesions. Fish with the Columnaris bacteria infection might occasionally have accumulated growth in their mouths. The best preventive approach is to lower the stress levels among the fish population.
The type of infection—internal or external that causes Columnaris often affects the course of treatment. However, for all outbreaks of Columnaris, antibiotic therapy using medicated feed is also advised.
On the other hand, to treat the water, chemicals declared acceptable for food fish should be used. Permanganate is usually used in this case.
5. Enteric Septicemia of Catfish (ESC)
In farming, ESC is the most deadly disease caused by enteric bacteria affecting the gastrointestinal tract and catfish population. All stages of catfish are susceptible to this disease, usually caused by the bacteria Edwardsiella ictaluri.
Physical manifestations of infection include bulging eyes, red blotches on the body, a bloated tummy, and holes on top of the head. Fish with the condition will halt or stop feeding and swim erratically as it worsens.
In severe cases, fish may die within 48 hours of infection.
The typical treatment for ESC outbreaks is a two-week antibiotic feed regimen. Before beginning treatment, a physician should certify the presence of ESC.
Different strategies can be used to treat ESC. A good pond manager makes daily observations of feeding response, behavior, and mortality. Fish specimens should be delivered or transferred to the closest aquatic diagnostic laboratory as soon as an unusual trend appears so that a complete diagnosis may be made.
The pathogens involved should be identified by the diagnostic lab, and antibiotic susceptibility tests should be run if E. Ictaluri is isolated. Fish should be treated as soon as feasible with medicated feeds once an effective authorized antibiotic has been found because fish gradually lower feed intake when ill. In the end, this reduces the effectiveness of medicated feed treatments.
Antibiotics should be used following a fish veterinarian’s or health specialist’s advice.
Challenges in Prevention and Control Of Catfish Diseases
Due to the environment in which catfish live and the characteristics of the fish, it is reasonable to say that controlling infectious diseases is difficult but not impossible. This is because fish cannot be observed closely enough.
Unlike every other animal, the environment can quickly facilitate the spread of disease. Catfish cannot easily gather without stress, frequently congregate in groups, and disease is difficult to detect and treat.
A disease can spread swiftly, and the entire tank/pond may be where healthy stock picks up the illness. The entire tank needs to be examined and diagnosed in this instance rather than just one fish, which is the unit of interest.
Aquatic animal diagnosis is difficult and intricate because samples must be taken from fish and water to test vital factors such as pH, soil bottom conditions, and turbidity.
Fish farming is a significant global business that is expanding quickly. Thus, the industry has faced several complex and multidimensional limitations and obstacles. Infectious diseases account for most of these problems, costing billions each year.
In summary, below are 5 of the most common diseases and treatments for catfish:
- Proliferative Gill Disease (PGD) – Can be treated by constantly changing the old water and replacing it with fresh water.
- The Channel Catfish Virus (CCVD) – Can be treated by separating the fry pond from other ponds (disease carriers)
- Brown Blood sickness – It can be treated using salt
- Columnaris Diseases – Can be treated using antibiotics applied to their feeds.
- Enteric Septicemia of Catfish (ESC) – Can be treated using antibiotics as specified by a Vet.
Now that we’ve discussed the diseases and treatments of catfish, it is advised to use a problem-planning, preventive, and control strategy based on globally recognized concepts and locally appropriate solutions to avoid further losses.
Instead of treating sick stocks, these tactics will concentrate on preventing the spread of diseases.
Therefore, the best health protection for catfish can be achieved using a mix of immunoprophylaxis, biosecurity measures, and using only legally allowed antibiotics.