About animals

Do fish get colds?


Asphyxia is a condition that occurs due to a lack of oxygen. Asphyxia can result in death.

Causes. Asphyxia occurs in an overpopulated with insufficient oxygen in the pool, at too high temperatures, as a result of decay of dead fish and food debris that are not removed in time from the "home".

Symptoms Fish massively rise to the surface of the water and actively swallow air, which lasts for several hours. Gills protrude from individuals.

Treatment. Initially eliminate the cause of asphyxiation. Then part of the water is changed and aeration is carried out. If this is not possible, temporary assistance can be provided with a 15% solution of hydrogen peroxide at a rate of 1 g / l. You can’t reapply this product, as the fish may die.

Associated with a high ammonia content. This is a product of the vital activity of fish, even in small quantities it becomes toxic to individuals.

Causes. With an increase in the amount of ammonia in water, an alkaline reaction occurs. The cause of acididemia is a rare replacement of water with fresh water, also overpopulation of the basin, and the accumulation of decaying organic matter.

Symptoms The color of the fish darkens, they stay on the surface of the water due to a lack of oxygen, sometimes they strive to jump out of the pond / pool or reservoir. Gills may be damaged.

Treatment. Treatment begins with a partial replacement / renewal of water, which will help save the fish. If there are a lot of individuals in the reservoir, it is recommended to install an additional filter, turn on the compressor. For prevention, it is advisable to measure the amount of food, fish and the size of the pool. Immediately remove from the container the remains of food, dead fish.

Alkaline disease (alkalosis)

Alkalosis is associated with an increase in the level of acidity of the medium. The consequence is the dullness of the skin of the fish, the release of mucus from the gills.

Causes. In a tank with soft, acidic water, densely planted with plants and in intense sunlight there is a risk of a sharp jump in acidity. A long stay of fish in such an environment can cause alkalosis.

Symptoms Residents of the reservoir become quicker breathing, they begin to spread their fins and rush about capacity. Noticeable coordination disorders, convulsions. Fish make attempts to jump out of the water.

Treatment. Immediately after the establishment of the disease, the fish are transplanted into the pool with a hydrogen index of 7.5-8. In a pool with a high level of acidity, the value is gradually brought to an optimum low. It will be possible to achieve the desired indicators with the help of a special pH buffer.

This is the physiological reaction of the body to sudden shocks of various types. Usually, a shock is manifested when too one or several environmental factors change (in particular, the temperature or chemical composition of the water).

Causes. Usually a shock is observed in fish that have just been launched into a pool / pond, but often such an ailment is manifested due to a partial change / change of water, if attention is not paid to this parameter.

Symptoms The color intensity decreases, fish hide among plants or other objects, in individuals accelerated or slowed breathing, they periodically sharply move to another place.

Treatment. If the shock begins rapidly and clearly, the cause is initially established, and then treatment is started. If all the inhabitants of the reservoir are affected, change the conditions in it. If recently launched fish were shocked, they are transferred to more suitable conditions (water with the usual parameters).

Gas bubble disease (gas embolism)

During a gas embolism, the fish begins to behave shyly: lose coordination in case of eye damage, swim on its side. This indicates the need for urgent action.

Causes. Not sludge water, which filled the pool or pond. It contains many air bubbles leading to gas embolism. Another reason is immoderate pool aeration. From a large number of plants with too intense lighting, excessive saturation of the “home” with oxygen can occur.

Symptoms It appears in the form of bubbles on the body and eyes of the fish. Bubbles can also appear on the internal organs of the fish, which can be fatal in 60-80% of cases. Sluggish fish, refuses to feed. The fins begin to twitch convulsively, the gills move less frequently, the eyes become cloudy, and the coordination of movements is disturbed.

Treatment. To eliminate the excess of gases dissolved in water will help the method of settling the supplied water in the intermediate pools with minimal movement of water. After 18-24 hours, the gas regime is fully normalized.

Catarrhal disease

Long-term keeping of fish at an unacceptable temperature of the water leads to a cold, due to which the activity of individuals decreases, they swim on the surface.

Causes. It arises in connection with the content of fish in colder water than is permissible. Usually warm-water fish are kept in water at a temperature of 22-27 degrees, cold-water fish are 18-22 degrees.

Symptoms Cold individuals become dark, earthy, their gill lobes swell and darken, growth slows down, dystrophic changes are observed in the internal organs. Because of this, fish produce immature caviar and milk. Fry die.

Treatment. Normal conditions are created for infected individuals by raising the temperature to an optimal level. Water is pumped with oxygen, disinfectant drugs are used.

In obesity, fish may have difficulty moving. Obesity is accompanied by invisible internal problems: digestive tract disorder and functional infertility resulting from the formation of fatty deposits around the gonads, the liver swollen with fat.

Causes. High nutritional food in which the fat content for plant individuals is more than 3%, and for carnivores 5%. Obesity also occurs when overfeeding, improper or monotonous feeding of fish, including dry food. A common cause is a densely populated pond or pool where fish cannot swim freely and lose calories.

Symptoms A large girth of the body in the abdominal region, as well as the area between the head and the abdominal region.

Treatment. A medical diet and a strict feeding regimen will help to cope with the problem. It will not hurt the fish to reduce food intake to an absolute minimum until her body again becomes as nature intended.

Sexual cyst

Sexual cysts occur when fish are divided by sex. It proceeds chronically, due to which it is detected late, when milk or caviar has already succumbed to changes.

Causes. Long-term maintenance of females and males separately, excessive feeding with dry feed.

Symptoms The belly is greatly increased, because it contains a lot of liquid or porridge-like contents. This causes severe pressure on the genitals of the fish, which leads to impaired functions and metabolic processes in the body as a whole. The neglected form is fraught with the death of the fish - the cyst ruptures.

Treatment. It is treated only at the initial stage. To do this, put the fish upside down in a cotton moistened with water and gently stroke it from the pectoral fins to the caudal fin - this is how the contents of the tumor are squeezed out. Such actions help to achieve a positive result.

Gastrointestinal inflammation

This is a common problem observed in fish. Dry food is poorly absorbed and causes inflammation of the mucous membrane of the gastrointestinal tract of fish.

Causes. Fish caught in the wastewater of a pond are fed into a pool or artificial pond when fed with dry daphnia, hamarus, bloodworms. Also, fish suffer from inflammation of the digestive tract due to the consumption of poor-quality feed.

Symptoms Fish eat well, but seem lethargic. Their skin darkens, the belly slightly increases. Redness of the anus, a filiform form of feces with bloody mucus, also testify to intestinal inflammation.

Treatment. Inflammation is treated simply: fish are transferred to a varied, full-fledged feeding with live hydrobiopts. It is undesirable to get live feed in water bodies, where sewage from domestic and industrial enterprises comes.


Invasive disease of freshwater fish. In pond fish farming, young fish weakened by wintering are affected. But often chylodonellosis appears in warm-water ponds.

Causes. Chylodonellosis, externally manifested in the formation of coarse-grained formations of a gray-blue hue from mucus, at the initial stage of the development of the disease is noticeable only from a certain angle of view, caused by three types of ciliates from the genus Chilodonella - Ch. hexasticha, Ch. cyprini (piscicola) and Ch. uncinata.

Symptoms Infected individuals begin to rub against stones and plants, press their fins. Appetite decreases occasionally. On examination, when the fish is located upside down, a bluish-matte coating is visible along the lateral line. Sometimes the skin behind flaps. Often, the infection of the gills provokes the mass death of fish.

Treatment. Before starting treatment, the fish are kept at a temperature of 30-32 degrees, which helps to restore strength. If symptoms are noticed at a time when the fish do not refuse to feed, the recommendation is not necessary. It will be effective to treat simultaneously with the use of a reduced dosage of Sera Mycopur. Chylodonellosis is also treated with antibiotics.


An invasive disease caused by monogenetic flukes. About 150 species of monogenes are known.

Causes. The causative agent of dactylogyrosis is a fluke from the genus Dactylogyrus, which has an elongated body.

Symptoms A fish infected with a parasite loses its appetite, stays at the surface, eagerly swallowing air, rubs against objects. A thick layer of mucus appears on the gills of an animal, resembling a mosaic. Gill petals grow together.

Treatment. The infected individuals are transferred to the quarantine pool, where a 0.2% ammonia solution is added previously at the rate of 2 ml per 1 liter of water. For the treatment of fry in growth and fry ponds, chlorophos solutions are used (the preparation is added at the rate of 0.6-1 g per cubic meter of water). In a common reservoir, larvae without fish will die within 24 hours. When buying new individuals, they are quarantined. Disinfect the container with a solution of baking soda.


An ailment during which fish suffer from loss of appetite, their breathing becomes frequent, a complete slowdown of the reaction occurs. Fish die, turning on their side.

Causes. Trichodinosis occurs due to ciliary infusoria, it has a round body shape and a reddish tint. The parasite lives on the skin and gills. It enters an artificial pond from a natural reservoir, where fish are found, with soil and plants.

Symptoms The body of infected individuals is covered with a dull mucus, which prevents the fish from breathing normally. In the initial period, the fish worry, constantly float to the surface of the water to swallow air. The gills also have a thick layer of mucus.

Treatment. Carry out aeration by adding methylene blue. In an empty pond without fish, ciliates die in 2-3 days. As therapeutic preparations, organic dyes, sea water, solutions of active chlorine and sodium chloride are used. Processing is carried out after 24-48 hours. Only 3-4 treatments. For prevention, it is imperative to observe hygiene measures, move new individuals to quarantine before moving to other fish.


Infection with hydrodactylosis can lead to the death of fish in the common pool within a week. In fish with such a disease, appetite disappears, and a plaque appears on the skin and gills.

Causes. It is caused by monogenetic flukes by gyrodactylus from the family of the class Monogenea.

Fluke fingerprints under multiple magnification of a microscope

Symptoms The affected fish sway and stay on the surface of the water, their fins are tightly compressed. As the disease progresses, the fish begin to rub against objects. Separate blue or gray patches appear on the surface of the body, the eyes become cloudy, and a raid forms on the gills.

Treatment. For treatment, salt baths from a 5% sodium chloride solution are used with an exposure of 5 minutes. In winter, it is permissible to add purple “K” to the ponds at the rate of 0.2 g per cubic meter. m. For preventive purposes, observe hygiene rules, regularly disinfect the tank. Before planting fish to spawn during the day, it is necessary to treat the pool with a solution of sodium chloride.

The causative agent is sporozoans - they are colonized on tissues, internal organs, gills. When ingested, they mate, forming white nodes that appear on the body of the fish.

Causes. The parasite can get into the pond along with sick fish, when the disease is only at the initial stage. Fish of the cyprinid family are particularly susceptible to glugeosis.

Symptoms It is accompanied by bloody spots that turn into ulcers, unilateral or bilateral buccal eye, pineal-shaped protrusions on the body of the fish, swimming on its side.

Treatment. Today there is no way to get rid of the problem. If glugeosis is established, it is advisable to get rid of all the plants and fish contained in the pond.

During lerneosis, sick fish are depleted, refuse to feed, lose their mobility, accumulate in the water duct and die.

Causes. This is an invasive disease of freshwater fish caused by the copepod Lernaea cyprinacea from this family. Lernaeidae, parasitic on the body of individuals.

Symptoms Parasites invade the skin and reach muscle tissue, penetrating deep into it, located on the entire surface of the body. In places where crustaceans are introduced into tissues, an inflammatory process occurs: swelling, hyperemia, leading to the formation of ulcers. Scales not only deform and rise, but also fall out.

Lerna copepods attached to fish

Treatment. Lerneosis is difficult to treat. Use various drugs and various treatment methods. For sick fish, it is recommended to prepare a quarantine pool with optimal conditions and add sodium chloride solution at the rate of about 20 g of salt per 10 l of water. Fishes are kept in such a solution until complete recovery and wound healing.

Octomitosis (hexamitosis)

This is a parasitic disease that adversely affects the gallbladder and intestines. Outwardly, it is easily determined by the presence of holes, ulcers and furrows. For this reason, hexamitosis is also called a “hole” disease.

Causes. Failure to comply with basic conditions for caring for the inhabitants of the reservoir or pond. These include a lack of minerals or vitamin deficiency (which leads to a decrease in immunity), rare or excessive feeding, use of poor-quality or spoiled food.

Symptoms The fish lose their appetite, they become picky during meals, white mucous secretions appear. The abdomen also swells, the fins collapse and fall off, deep erosion appears on the sides of the body of the fish, the anus increases.

Treatment. Initially, infected fish are moved to the quarantine pool, due to which it will be possible to prevent the development of the disease in a common vessel. After that, in a separate container (quarantine), the water temperature is increased to 34-35 degrees - this contributes to the detrimental effect on part of the parasites, leading to their death.

Ichthyophthyroidism ("semolina")

All species of fish are exposed. The people call it “manna disease” due to the formation of white grains on the fins and scales of fish.

Causes. The causative agent is the ciliary infusoria.The parasite is highly adaptable.

Symptoms Fish often breathe, begin to itch on objects and hard surfaces, subsequently suffer from white plaque in the form of grains.

Treatment. As a preventive measure, quarantine is recommended - beginners should not be immediately launched into a common pond. For treatment, it is permissible to add water and raise its temperature - the parasite does not tolerate a salty environment and an increase in the temperature level of water. Also, bactericidal drugs are used to combat ichthyophthyroidism.

Mycobacteriosis (tuberculosis)

Viviparous species of fish suffer from mycobacteriosis. Their behavior changes, their appetite disappears.

Causes. Carried with food, plants or soil. With fish and shellfish. There are cases when insects that flew to drink water became the cause of mycobacteriosis. Improper conditions of detention, weakened immunity lead to the development of mycobacteriosis.

Symptoms Fish become sluggish, bulging eyes, they lose orientation, some go blind. Also, animals suffer from ulcers, tears, blindness, apathy.

Treatment. It is carried out at an early stage: for this, the use of Monocycline, Tripoflavin, copper sulfate is recommended.

Aeromonosis (rubella carp)

A bacterial infection of cyprinids, when scales flake over the entire surface of a fish’s body, begins to fall out. Treatment can lead to recovery or death of the individual.

Causes. Aeromonosis is brought into artificial ponds and pools from natural reservoirs, when the fish, non-quarantined, are re-settled with soil, vegetation, water. The infection spreads due to poorly sanitized equipment, tools.

Symptoms In the acute course of the disease, fish die en masse. Serous-hemorrhagic inflammation of the skin, hydremia of tissues of organs, muscles appear on the belly, fins, side walls of the trunk. In the chronic course, open and scarring ulcers form, accompanied by anemia of the liver and swelling of the kidneys.

Treatment. Aeromonosis can be treated only at the initial stage. Fish with abdominal dropsy and raised scales are destroyed. Outwardly healthy fish must be processed by immersing in a separate vessel using the main violet K (Chlorohydrite, a synthetic dye), Bicillin-5 or soluble white streptocide per 100 l of water of 15 g are poured into a common tank.

Salmon furunculosis

Furunculosis is an infection characterized by septicemia, the formation of boils in muscle tissue, followed by rupture and their transition into reddish ulcers.

Causes. The causative agent of furunculosis is the bacterium Aeromonas salmonicida.

Symptoms When infected with furunculosis, spotted hemorrhages of various sizes and shapes appear in the fish, the belly increases, the eyes bulge, in some parts or throughout the body, ruffled scales. Inflamed fins often have a blood red hue.

Treatment. For the prevention of furunculosis, it is required to prevent the introduction of the pathogen with water, fishing gear, caviar, fish and other hydrobionts. Caviar for prevention is recommended to be treated with solutions of Acriflavin or Merthiolate. To avoid further spread of furunculosis, the developed complex of therapeutic and preventive measures will allow: caviar is treated with acriflavine, iodinol or formalin. For the treatment of sick fish, they are fed with feed with the addition of sulfanilamide preparations at the rate of 120 mg per 1 kg of fish weight for 14 days.

Bacterial Fin Rot

With this disease, the fin disappears in the fish. Ulcers appear at its base, the spinal column is exposed, this leads to death.

Causes. It occurs in connection with an infection that destroys the fins of fish. The causative agent is the wand. The development of fin rot provokes non-compliance with the rules of care, a rare change or purification of water in a pond or pool.

Symptoms. At the beginning of the disease, at the edges of the fins, a slight turbidity of the color of a bluish-white hue appears. The fins along the edges are disheveled, the ends of their rays gradually disappear.

Treatment. They are fighting radically. Initially improve fish conditions. With a severe lesion of the fins, medications can not be dispensed with. Regularly disinfect the pool.

Lepidortosis (infectious erosion of scales)

Lepidortosis is slow. After it, the fish die, but with timely treatment it will be possible to achieve a successful conclusion.

Causes. The causative agents are bacteria that enter the artificial pond from a reservoir where there is fish with food.

Symptoms At the initial stage, affected individuals suffer from the fact that in some areas the scales are ruffled. Gradually, the phenomenon spreads to the whole body. Soon, the scales begin to fall out, which leads to death.

Treatment. Treatment of infected fish is permissible at the initial stage. It is recommended to conduct therapeutic baths with the drug Biomycin or Bicillin-5. When treating in a separate vessel, the use of the main violet K. is permissible. If therapy does not bring results, the fish are killed, and the pool and other equipment are disinfected.

Pseudomoniasis (peptic ulcer)

Symptoms are developing rapidly. In most cases, peptic ulcer leads to the death of fish.

Causes. Caused by bacteria entering the pool with food or from sick relatives. The sources of pathogenic pathogens include poorly defended water. The bacterium may be in the container with human hands.

Symptoms It is accompanied by the appearance of dark spots on the skin of the fish, gradually they turn into ulcers. Also, the fish’s belly becomes larger, their eyes bulge, their appetite decreases, their scales ruffle. Infection enters the body.

Treatment. It is required to start treatment in a timely manner. For control, streptocide is used, having dissolved one tablet in 10 l of water. They also treat fish with potassium permanganate by dissolving it directly in the pool - 5 g of solution falls per 10 liters of water. Fish should swim in such a solution for about 20 minutes, then collect clean water.

White-skinned (exc. ​​Pseudomonas dermoalba)

Infectious, serious disease that negatively affects the body of fish, therefore it requires good treatment immediately after the first symptoms are detected.

Causes. The defeat of the fish organism by a pathogenic bacterium that can enter the pond from a natural reservoir along with diseased fish, soil and plants.

Symptoms Whitening of the skin in the dorsal fin and tail region is observed. The fish keeps closer to the surface, often exposing the fin out. The color turns white. Lack of treatment may be accompanied by damage to the central nervous system and organs responsible for coordination of movement. This is fatal.

Treatment. It will be possible to prevent compliance with basic hygiene rules. Affected fish are moved to another container for quarantine. Dissolve 150-200 mg of Levomycetin in 1 liter of water, the composition is poured into a reservoir with sick fish. In such conditions, they contain at least 5 days.


This is a fungus that affects the gill apparatus of fish. The causative agent of branchiomycosis is Branchiomyces demigrans and Branchiomyces sanguinis.

Causes. Mushrooms settle on gill petals. From the disease can affect all species of fish contained in inappropriate conditions. The disease develops due to the high temperature of water, organic compounds of dead plants. There is a rapid development of the disease.

Symptoms Ill fish do not have enough oxygen, pinpoint hemorrhages are visible on the gill leaves, and the gill covers are deformed. Fish refuse to feed, always swim at the surface of the water, scooping up air with their mouths. Bright red and pale spots become visible on the gills.

Treatment. When the first signs appear, all fish are transferred to the quarantine pool and treated with malachite green oxalate, and the viewing tank is cleaned and disinfected. Cleanliness and hygiene in the pool will help to avoid branchiomycosis.


Dangerous fungal disease of pond and aquarium fish. Caused by an allegedly imperfect Phycomycetes fungus.

Causes. The causative agent is Ichtyophonus hoferi, having a round or ovoid shape. Around the fungus is the formation of a capsule secreted by the affected organ. Hyphae are also observed in the form of blunt outgrowths, stained into an independent rounded body.

Symptoms The causative agent is carried hematogenously in various organs and tissues, where inflammation first develops, then the affected areas are encapsulated. In case of dysfunction, the fish stops responding to stimuli, its movement becomes erratic and lethargic. She keeps off the coast. In case of damage to the liver and kidneys, there is observed eyebrows, erosion of scales, ascites. The localization of the pathogen in the subcutaneous tissue, muscles and eyes leads to bumpy swelling and ulcers, black spots on the skin.

Treatment. Not developed. But they must control the process of transporting fish. It is imperative to feed the fish with sea relatives only after heat treatment. It is also desirable to timely disinfect ponds with quicklime or bleach for prevention purposes.

Saprolegniosis ("cotton disease")

Mycotic disease of most fish species caused by opportunistic aquatic fungi from the class Oomycetes. More often this is a secondary disease, first injured parts of the body or damaged eggs are affected, then the disease passes to healthy areas and eggs.

Causes. The causative agents of the disease are representatives of the genera Achlya and Saprolegnia. The mycelium of these fungi is formed by hyphae with a limited number of transverse septa.

Symptoms The most characteristic sign of the disease is cotton-like, fluffy white growths on the caudal and dorsal fins, head, olfactory fossae, eyes and gills. Before the death of the fish, a loss of balance was noticed.

Treatment. In summer and autumn, for prevention, it is recommended to treat the fish twice with the main purple K at the rate of 1 g per cubic meter. m of water for half an hour. Also suitable are 0.1% salt baths for 30 minutes. To combat the disease, disinfect the water that enters the incubation workshops with ultraviolet rays.


With this ailment, the eyes swell greatly, often completely fall out. This symptom occurs with an infectious infection, for example, with ichthyosporidosis, mycobacteriosis, etc. The method of treatment directly depends on this.

Causes. Glaucoma can occur due to infection of fish with viruses, bacteria or fungi. Along with this, physiological failures, trematodes, eye nematodes (worms), and a lack of vitamins (vitamin deficiency) are referred to provocateurs.

Symptoms Blurring of the whole eye, the appearance of a whitish film, the eye moving away from the body. Running cases lead to the loss of one or both eyes.

Treatment. If hepatitis occurs due to a bacterial infection, it is initially treated using antibiotics and adding them to food. In the event of a problem due to inappropriate living conditions, begin by eliminating them: regularly clean the water, feed the fish in a balanced manner.


Dropsy is accompanied by severe bloating, puffed scales. The fish becomes lethargic, breathing heavily.

Causes. The reasons for an increase in the abdomen include mycobacteriosis, aeromonosis, nocardiosis. In addition to bacteria, the cause of bloating can be a virus (spring viremia). With a cyst of the gonads, an increase in the abdomen of females is also observed.

Symptoms Swollen belly, clear skin due to a strong increase in the abdomen, curvature of the spine.

Treatment. The fish is immediately precipitated, observed and inspected. Fish are treated depending on the causes of the enlargement of the abdomen, but most often the fish die if bloating is caused by a bacterial infection.

If you learn to recognize the causes and symptoms of diseases, you can prevent them or cope with ailments using effective methods. Compliance with simple hygiene rules, frequent water changes, and feeding fish with high-quality food will reduce the risk of infection of fish that are bred in natural or artificial conditions.