Current location - Plastic Surgery and Aesthetics Network - Plastic surgery and beauty - Prevention and treatment of diseases in koi fish
Prevention and treatment of diseases in koi fish
1. oral method: drugs are mixed in the feed to treat malnutrition or bacterial diseases and internal medicine diseases.

2. Medicated bath method: it is mainly to drive away parasites on the body surface and treat bacterial exogenous diseases.

3. Local treatment: treatment of trauma and body surface diseases, and treatment of local trauma.

4. Injection therapy: various bacterial diseases can be injected into muscles or abdominal cavity.

5. Surgical treatment: plastic surgery for injured or deformed fins. cowpox

(1) Etiology: It occurs in late autumn and early winter when the water temperature is low (about 15 degrees).

(2) Symptoms: At the early stage of onset, milky white spots appear on the body surface or caudal fin, and the surface is covered with a thin layer of white mucus, which gradually expands and spreads to the whole body. The damaged skin surface thickens to form large paraffin-like growth. When these growths reach a certain size and thickness, they will automatically fall off, making the water quality worse, and new growths will grow again at the falling parts. The sick fish infected with acne gradually lose weight, swim slowly, have poor appetite, often sink to the bottom and die one after another.

(3) Treatment: #0. 1~0.3MG/KG chloramphenicol solution is used for a long time.

Inject chloramphenicol into the fish at a dose of 25 mg per fish.

(4) Prevention: Fill the # pond with fresh water, and extract the sediment at the bottom of the pond at any time to improve the water quality.

Strengthen autumn nourishment and nutrition, so that koi fish can have a certain degree of fatness before winter, and enhance its ability to resist low temperature and disease.

Spraying nitrofurazone 1~2MG/KG in the whole pool to prevent acne.

Common diseases and treatment methods (3) dermatomycosis

(Water mold, white disease): Fish has a layer of "white hair". If not treated in time, when bacteria invade the body, fish will gradually weaken and die. When parasitic in gills, gill mold is formed, which often causes explosive death.

(1) Etiology: Dermatomycosis is caused by a kind of filamentous bacteria (Shui Mu, Mianmu, Shuimu), which mostly occurs in pools with a large number of fish or turbid stagnant water. For example, if a fish loses weight or is injured, it is more susceptible to infection, and many cotton-wool hyphae grow in the lesion, so it is also called white disease.

Koi fish suffers from dermatomycosis, which is mainly caused by careless fishing and handling, scratching the skin, or parasites damaging the gills and body surface, or frostbite of the skin due to low water temperature, so that myxomycetes spores invade the wound and become infected. When the water temperature is suitable (about 15~25℃), it will grow into dense mycelium in 3~5 days, and a large number of infections will lead to the death of sick fish. Water mold is found all year round, and late autumn and early spring are popular seasons. Fish eggs can be infected from all ages, and when the incubation temperature is low, water mold is easy to occur on fish eggs.

(2) treatment:

Wash with 1.5%~2.5% salt solution, remove hair, then apply 2% mercuric chloride, and then bathe the fish with oxytetracycline.

Use 0. 1%~ 1% malachite green aqueous solution to smear the wound and the attachment of water mold.

Soak the fish in malachite green water solution of 1: 15000 for 3~5 minutes. # Soak the fish in 10MG/KG potassium permanganate solution for half an hour.

(3) Prevention:

Be careful when pulling nets, fishing, transporting and stocking fish, so as not to hurt fish.

Soak fish eggs 1: 15000 in malachite green water solution for 0/0 ~ 1 5 minutes, once a day1time for 3 consecutive days, which can prevent fish eggs from getting moldy.

Injured parent fish can be prevented from being infected by water mold by applying gentian violet or potassium permanganate to the wound.

Each hectare of pond is mixed with 75 kg of Acorus calamus, 7.5 ~ 15 kg of salt and 225 ~ 300 kg of human urine, and sprayed all over the pond once a month 1 time.

Common diseases and treatment in koi fish (IV) Skin inflammation and congestion.

(1) A large number of fish died. It is most popular when the water temperature is 20~30 degrees. When the temperature is below 20 degrees, there will still be a few sick fish, and they will continue to die. This temperature range is also the peak season for fish growth, so it is very harmful. When the temperature drops to about 10 degrees, fish diseases no longer occur, and this law can be used to control the temperature of sick fish.

(2) Symptoms: the skin is red, swollen and hyperemia, which is more common around the orbit, gill cover, abdomen and tail handle. Sometimes there will be congestion at the root of the fin, and in severe cases, the fin will break. The scales of diseased fish are usually intact and have not fallen off. Sick fish float on the water meter or sink at the bottom of the water, swimming slowly, being slow to respond and having poor appetite.

(3) Treatment: soak and clean the fish with 20MG/KG penicillin or furazolidone. Soak for 20-30 minutes when the water temperature is below 20 degrees; When the temperature is 2 1~32℃, soak 10~ 15 minutes for prevention and early treatment.

When the concentration of furacilin or furazolidone is 0.2~0.3MG/KG, it can be increased to 0.5~ 1.2MG/KG for prevention and early treatment.

The fish body was soaked with erythromycin 2~2.5MG/KG, the water temperature was below 34℃, and the fish body was soaked for 30~50 minutes, 1 time, 3~5 days a day, until the condition improved.

Inject streptomycin or kanamycin, and inject 120000 ~ 150000 international units per kilogram of fish. Usually only 1 injection is given, and the second injection can be given on the fifth day when the patient is seriously ill.

# Take norfloxacin orally, and take 0.8~ 1.0G powder every 10KG fish once a day for 6 days.

Dip and wash with rivanol 20MG/KG, soak and wash 15~30 minutes when the water temperature is 5~20 degrees; Soak at 2 1~32℃ for1~15 minutes. Used for early treatment, the effect is remarkable.

The concentration of rivanol 0.8 ~ 1.5 mg/kg has special effects.

Using the above treatment method and salt water bath at the same time, the effect is remarkable.

(4) Prevention:

Reasonable close planting, keep the dissolved oxygen in the water at about 5 mg/L # Strengthen feeding management, and keep the water fresh.

Regularly spray furacilin or furazolidone to prevent diseases. (Hemorrhagic corruption)

(1) Etiology: Erythroderma is caused by Pseudomonas fluorescens. Fish are injured and prone to this disease. Spring and autumn are popular seasons, which will cause a large number of fish deaths. This disease is closely related to water quality, and it is easy to occur when dissolved oxygen is low and organic matter content is high.

(2) Symptoms: local or most of the skin of the diseased fish is red and swollen or congested, the base of dorsal fin and caudal fin is congested, the end of the fin is rotten, and the mouth and muscles are normal. Scales of diseased fish fall off (different from skin inflammation and congestion), especially on both sides and abdomen of fish.

(3) Prevention and treatment: same skin inflammation and congestion. Caused by Aeromonas punctata. The anus is red and swollen, and the intestine is congested and inflamed. In severe cases, the fin root is congested and erythema appears in the abdomen. Ascites flows out during laparotomy and the whole intestine is red or purple.

Prevention and control methods:

Sprinkle the pool water with bleaching powder 1MG/KG.

Every hectare of water depth 1M, spread the pond with 225~375KG of quicklime.

Each fish 10KG is fed with 1G sulfanilamide to make drug bait.

Feed 50G garlic to each 10KG fish once a day for three days.

Every 10KG fish is fed 50G dried Euphorbia humifusa once a day for three days. (1) Etiology: It is caused by columnar fibrinococcus, also known as Myxococcus pisi. There are fewer diseases in koi fish, and only when the water temperature is above 20 degrees, that is, from late spring to autumn, will the disease occur. A large number of fish died without any appearance abnormality.

(2) Symptoms: The gill filaments of the diseased fish are rotten, with some sludge. Sometimes the tissue at the tip of gill filament rots, resulting in incomplete edges; Sometimes it will rot in one or more parts of the gill, but not at the edge. The inner epidermis of the branchial lid bone is congested and even corroded into a slightly round transparent area, commonly known as "opening the skylight". Due to the destruction of gill silk tissue, sick fish have difficulty breathing, and often appear floating head, resulting in a large number of deaths.

(3) treatment:

Soak fish with 20MG/KG furacilin or furazolidone. Soak for 20-30 minutes when the water temperature is below 20 degrees; When the temperature is 2 1~32 degrees, soak it for 10~ 15 minutes for prevention and early treatment.

The concentration of furacilin or furazolidone is 0.2~0.3MG/KG, which can be increased to 0.5~ 1.2MG/KG in severe cases for prevention and early treatment.

Dip and wash with rivanol 20MG/KG, soak and wash 15~30 minutes when the water temperature is 5~20 degrees; When the temperature is 2 1~32℃, soak 10~ 15 minutes. Used for early treatment, the effect is remarkable.

The concentration of rivanol is 0.8~ 1.5MG/KG, which has special effect.

Spray bleaching powder with the concentration of 1MG/KG to all parts of the pond. This method is only used in outdoor big fish ponds. Use rhubarb 2.5~3.75MG/KG, soak every 0.5KG of dry rhubarb in 10KG of dilute ammonia water (0.3%) 12 hours, and sprinkle it all over the pool with the residue. This drug is suitable for outdoor ponds, especially for koi fish aquaculture which has been using furan for many years and has developed drug resistance.

Soaking in 2% salt for 5~ 10 minutes is effective for prevention and early treatment.

(4) Prevention:

Disinfect fish ponds regularly to keep the water clean and reduce the chances of bacteria breeding.

The use of fresh feed and biological live bait has obvious effect on preventing the disease. (1) Etiology: It is caused by the genus Phaeophaga. , also known as Myxococcus. Koi fish fry are very sensitive to this disease, which is one of the main diseases in fingerling period, while big fish generally do not get sick. Only two or three people died at first, and the number increased to several ten tail the next day. On the third day, a large number of people died, and the onset was fast and fierce. When the water temperature is above 20 degrees, that is, from late spring to autumn.

(2) Symptoms: The head and mouth ring of the sick fish are milky white, and the lips are swollen, so that the mouth cannot be opened and it is difficult to breathe. Some sick fish have congestion on the top of their heads and around their eyes, showing the symptoms of "red head and white mouth". Sick fish are usually unsociable.

(3) Control method: myxobacteria gill rot. (loose scale, vertical scale)

(1) Etiology: Squamous disease is caused by Pseudomonas punctata, which mainly harms koi fish, a large individual fish. It is the popular season from late autumn to the following spring when the water temperature is low.

(2) Symptoms: The diseased fish has rough body surface, erect scales and loose spherical appearance. In severe cases, exophthalmos, shortness of breath, back somersault and even death. The scales are swollen with transparent or bloody exudates. If you put a little pressure on the scale, the liquid will come out of the scale. The sick fish sank to the bottom of the water or lost its balance, its abdomen swelled, and finally died of exhaustion.

(3) Treatment: Just like skin inflammation and congestion, it will be better to soak in salt water.

(4) Prevention:

Prevent fish from being injured.

Parent fish spawning ponds should be aired in winter and disinfected with quicklime or bleaching powder.

Add 5% crude chlortetracycline or oxytetracycline to the feed.

Take vitamin E orally, 0.3~0.6G per 10KG of fish weight every day, and take it for a long time, and increase it to 0.6 ~ 0.9G( 10 ~ 15 days) as an adjuvant treatment. (1) Etiology: Printing disease is caused by Aeromonas punctata, which is mainly caused by improper operation, resulting in fish injury and infection. Late spring to autumn is the popular season, which mainly harms big fish over one year old.

(2) Symptoms: The lesions are often located above the body-side gluteal fin, on both sides near the anus, and rarely in the front of the body. At first, the skin became inflamed and erythema appeared. With the development of the disease, scales fall off, muscles rot, lesions are round or oval, and there are bleeding and redness, which seems to be marked with red marks. In severe cases, the muscles in the focus often rot through, and bones and internal organs can be seen. The sick fish lost weight, lost appetite, swam slowly, and eventually died of exhaustion.

(3) Prevention and treatment: The same skin inflammation and congestion, and the effect of applying potassium permanganate solution to the affected area is remarkable.

Rot skin disease (canker disease): It is very similar to Indian disease, and the treatment method is similar. The difference is that the back of the sick fish is red, swollen and rotten, and the lesion is not formed. In severe cases, the dorsal fin falls off. Caused by Trichomonas albicans, the skin from the back of dorsal fin to the base of caudal fin is white and foggy with rough scales and no mucus. Dying sick fish often have their heads down and their tail fins up, showing an inverted shape.

Prevention and control methods:

Be careful when operating to prevent fish from being injured.

Soak the fish in chlortetracycline 12.5MG/KG or oxytetracycline 25MG/KG for 30 minutes.

Fill the pool with bleaching powder 1MG/KG or gallnut 2~4MG/KG. (cave disease)

(1) Etiology: Perforation is caused by Myxococcus pisi, which is prevalent from September to June every year. When the water temperature is low, it is a very harmful infectious disease. Most of the reasons are injuries to the body surface, especially abrasions when fishing with nets.

(2) Symptoms: White spots about the size of rice grains were found at the initial stage, then expanded and turned red around. When the disease gets worse, the scales fall off, the flesh is exposed, and ulcers are produced. Lesions can appear from the head, gill cover, back, abdomen, fins and tail stalk. Ulcer is not limited to dermis, but also goes deep into muscles, and serious cases are caves.

(3) treatment:

Soak in the mixture of 20MG/KG furazolidone and 1.4% salt for 20~30 minutes, 1 time, daily 1 time.

The mixture was soaked in 20MG/KG potassium permanganate 10~30 minutes. Suitable for young fish at the early stage of onset.

(4) Prevention:

Feed fresh bait, strengthen nutrition and enhance disease resistance.

Reasonable closed culture can maintain the dissolved oxygen in water at about 5 mg/L.

Dead fish must be buried deep and disinfected with quicklime. Bleaching powder with the concentration of 10MG/KG should be sprinkled on the water in the sick fish pond, and then it should be discharged into the sewer after disinfection. (1) Etiology: Tail rot is caused by Myxococcus columnar, which occurs all year round. The whole caudal fin rotted, and the sick fish was still alive, which reduced the ornamental value of koi fish.

(2) Symptoms: the scales of caudal fin are exfoliated and inflamed, the muscles are necrotic and rotten, the caudal fin base is congested, the fin is scattered into a broom shape, and in severe cases, the entire caudal fin is rotten. The scales of diseased fish are normal, and some scales fall off.

(3) Prevention and control methods:

Roughly the same as skin inflammation and congestion.

Apply 1% malachite green aqueous solution to the broken wing,/kloc-0 once a day for 3~5 days to prevent and treat skin inflammation and congestion.

If a part of the caudal fin is rotten and incomplete, it should be cut off with scissors to flatten the fin, and then treated in the above way. After a period of time, the fin can heal, leaving traces between the regenerated fin and the old fin. Although the ornamental value is reduced, it can be kept as a parent fish to breed offspring.

Common diseases and treatments in koi fish (5) Oral filariasis.

(fish wave bean worm, white cloud disease): fish wave worm often inhabits the skin and gills of fish, and it will not cause disease when the number is small, but when the environmental water quality is poor or the fish is in poor health, it will often multiply in large numbers, destroy gills and skin tissues, lead to increased mucus secretion and white mist attachments, so it is called white cloud disease. This disease is mainly parasitic on freshwater fish, especially in koi fish, and often occurs after moving ponds, so it is also called new water disease. Koi fish fell asleep after being infected with this disease and sank in the corner of the bottom of the pool, so it is also called sleeping sickness.

(1) Etiology: Fistula is the most common oral filariasis. Worms are oval, with 2 or 4 flagella, and can rotate and swim. There are 1 round nuclei in the worm. The insect body fixed on the host is pear-shaped, the flagella is not obvious, and it can swing up and down and left and right in the tissue. The optimum epidemic temperature of oral filariasis is 2~30℃, and the water temperature at which the worm begins to breed is 65438 02 ~ 20℃, and it is easy to breed in large quantities at 24~25℃ and PH4.5~5.8. When breeding, the vertical binary division method can directly infect the transferred host without intermediate host; When the environment is not suitable, resistant cysts can be formed and attached to fish or pond bottom. The epidemic season of this disease is from late autumn to spring.

(2) Symptoms:

At the initial stage of infection, the fish will feel itchy and rub the bottom and wall of the pond.

There is a milky white or gray-blue mucus on the skin of the sick fish, which makes the sick fish lose its original luster. Fish wound is hyperemia and inflammation, which often leads to bacterial or water mold infection, forming ulcers and aggravating the condition.

When a large number of worms invade the skin, a large number of worms will also appear on the gills. Because the gill tissue is destroyed, which affects the fish's breathing, sick fish often swim near the water surface in a floating head shape.

Loss of appetite, listlessness, shrinking tail and pinching fins, gathering in the corner of the bottom of the pool, slow to respond, the fish gradually lost their balance, lying at the bottom of the pool, and finally failed and died.

(3) Diagnosis:

Worms are so small that they can only be seen under a microscope. Take the surface mucosa or gill tissue for microscopic examination.

Whether there is group sleepiness.

When the black and red parts of koi fish suffer from this disease, it is easier to be found; But when the white part is sick, it is not easy to distinguish. When it is found that it is Baiyun disease, it will be hopeless.

(4) treatment:

Soak in 2% salt solution for 5~ 15 minutes or 3 ~ 5% 1~2 minutes for several days.

Soak for 20-30 minutes, with potassium permanganate concentration of 20MG/KG and water temperature of10-20 degrees; When the water temperature is 20~25℃, soak 15~20 minutes; When the water temperature is above 25 degrees, soak for 10~ 15 minutes.

Use 300,000 ~ 500,000 units of penicillin for long-term immersion per 100 L water body.

Soak in 50MG/KG methylene blue or 0.2MG/KG malachite green solution for half an hour and several times.

The concentration of formalin is 20~30MG/KG, and it is used every 2~3 days 1 time for several times.

(5) Prevention:

Strengthening water flow can reduce the attachment and parasitism of oral filariasis.

Reduce the feeding density.

Keep the water clean and stable, and reduce the stimulation to gills or body surface tissues. CHILODONELLA CYPRINI of CYPRINIDAE attaches to the gills and skin of fish, which destroys the ecological balance of host parasites due to poor water quality, high fish density or other factors and often causes a large number of diseases.

(1) Etiology: koi fish (also known as cardioid worm) is the most common in koi fish. Worms are oval or kidney-shaped, with a size of about 50 ~ 70μ m, no cilia on the back, flat ventral surface, several cilia on the left and right sides, funnel-shaped mouth tube at the front end of ventral surface, and 1 large nucleus is oval. Feed on organic matter in water and cell fragments stripped from fish. Reproduction is mainly based on asexual transverse binary division, and sexual union also occurs. Spherical or elliptical capsules can be formed in unfavorable environment.

The disease is a common fish disease, which mostly occurs in small tanks and pools with unclean water quality, and is the most harmful to young fish in that year. The aquaculture water temperature is 65438 02 ~ 65438 08℃. Judging from the few bugs found, fish can die in large numbers after 3~5 days of mass reproduction. When the water temperature in the outdoor fish pond is above 25 degrees, you will not get sick, but you will get sick in the indoor water tank and pool. The annual epidemic season is 65438+February to May of the following year.

(2) Symptoms: The sick fish is thin and black, and there is a milky thin substance on the body surface, which makes the sick fish lose its original color. In severe cases, the fins of sick fish cannot be fully extended.

Pathogens parasitize on the body surface and gills, destroying tissues and making it difficult for fish to breathe. Therefore, the sick fish swim around the water meter in a floating head shape, and even if it is replaced by clean water, it still cannot return to normal.

(3) Diagnosis: Trichinella spiralis is very small, and it needs to scrape mucus or cut gill tissue before it can be seen under the microscope.

(4) Control method: Oral filariasis. Trichinella spiralis, also known as Lepidoptera, Lepidoptera and Lepidoptera, is a common sessile ciliate in water. Can be attached to the bottom of the pond wall, plants or other objects in the water, and feed on organic debris and microorganisms in the water. It is easy to breed in a high-temperature and eutrophic environment, and it is attached to the skin, fins and gills of fish, especially when the fish is injured, it is more susceptible to infection.

(1) Etiology: The bell worm is thick at the front and thin at the back, cup-shaped or trumpet-shaped, about 100~400UM in size, with a mouth plate at the front and a joint groove at the bottom. There is an edge film made of fluff around the mouth plate, which can swing to drive the water flow and filter the bacteria, microorganisms, tissue debris and other organic substances in the water. An attachment is formed at the bottom, and the attachment is fixed on the epithelial cells of the host. 1 The macronucleus is in the shape of an inverted triangle or ellipse, and is located in the center of the worm. When the worm shrinks, the mouth disc shrinks first, then the cilia of the mouth contract, leaving only 1 hole at the top, making the shrunk worm look like an eggplant. There are two ways of reproduction: asexual vertical binary division and sexual union. The common species are CERATOPOGONIDAE, Insecta, Vortex, Acrospora and so on.

Normal fish rarely have the epiphysis of bell worms. When a large number of epiphyses appear, it is mostly because of body surface damage or mucosal damage protected by body surface during transportation. Without the protection of mucus, a large number of bell worms will be attached.

(2) Symptoms:

At the initial stage of infection, white spots with the size of rice grains proliferated outward appeared on the body surface.

The affected part gradually expanded, and the wound was accompanied by secondary bacterial infection, showing flushing bleeding.

Scales fall off, the affected parts bleed and fester, and there are water molds, algae or other protozoa attached.

(3) Diagnosis:

Scraping the mucosal tissue of the affected area and examining it under the microscope, we can observe the bell-shaped worms that gather and contract, and there is a long branch handle at the lower end of the worms to connect them together. In addition to the bollworm, the mixed infection of oral filariasis, oblique tube worm and rotifer, as well as the epiphysis of water mold and filamentous algae can be often observed.

(4) Treatment: Fungal infection of bollworm is generally difficult to treat. In addition to drug control, it must also be coordinated with improving water quality environment and controlling secondary bacterial infection.

Improve the water quality environment: properly changing water to reduce the organic content in water and increase the intensity of water flow can reduce the occurrence of bollworm.

Formalin: the concentration of 20~30MG/KG, medicinal bath 12~24 hours, can reduce the epiphyte of bollworm.

Control of secondary bacterial infection: when there are inflammatory ulcers on the body surface, furazolidone 2~5MG/KG solution should be used in conjunction with long-term medicinal bath.

Fungi of chronic local wound ulcer can be disinfected with iodine and coated with antibiotic ointment, such as erythromycin, to protect the wound.

(5) Prevention:

Change the water regularly and clean the filter tank to reduce the accumulation of organic matter and keep the water pure.

Be careful when moving the pond for transportation to prevent fish from being injured or mucous membrane from being damaged.

When fish is injured or mucous membrane is damaged, it should be disinfected with drugs as soon as possible to prevent infection with bollworm or other secondary pathogens. 1, pathogen

Myxosporidia of protozoa Sarcocystis parasitize the gills or body surfaces of fish.

2. Symptoms

Myxosporidia is mainly parasitic on gill and body surface in koi fish. The white cysts are piled up in a tumor shape, and the parasitic parts of the cysts make the gill tissue form local congestion in purple or anemia in reddish or festering. Sometimes the whole gill flap is covered with cysts, which makes the gill cover incomplete, and white cysts can also be seen at the bottom of the scales on the body surface. The sick fish was very thin, had difficulty breathing and died of lack of oxygen.

Step 3 be popular

It mainly harms 1 and 2-year-old koi fish, and can cause a large number of deaths.

Step 4 diagnose

Myxosporidia is generally parasitic on the body surface and gills, and cysts can be seen with the naked eye. Take out the contents of koi fish's gill or body surface, put them on a glass slide, add a little water, and observe them under a microscope. We can find a large number of ovoid or ovoid or flat myxosporidia with two polar cysts of equal or unequal size at the front end, so that we can make a diagnosis.

5, prevention and control methods:

(1) Precautionary measures: Before stocking, the pond should be completely drained to remove excessive silt, and the pond should be aired in winter when conditions permit. Before stocking koi fish 10 ~ 12d, 6.5kg of bleaching powder and 50kg of quicklime water100 ~150kg were sprayed on each mu in the whole pond, which could kill the spores in the sludge and reduce the occurrence of this disease. You can't buy fry from sick fish farms to reduce the chance of illness and reduce the incidence.

(2) Treatment: use type C fish insecticide (deltamethrin vinegar for fish) to spray the whole pond, so that the concentration of pond water is 0.02×0.0000 1, 1 time /d, for three consecutive times. Or soak the sick fish in (400 ~ 500) × 0.00000 1 potassium permanganate solution for 25min (the water temperature is about 15℃), and the specific soaking time depends on the activity of the fish, 1 time every day, three times in a row. (1) Symptoms: local or most of the diseased fish's body surface is congested and inflamed, and scales fall off, especially the fish's sides and abdomen, dorsal fin and caudal fin are congested, accompanied by ascites and gill rot in the later stage.

(2) Pathogen and cause of infection: It is caused by Pseudomonas fluorescens, which is a bacterial disease and easily transmitted to other healthy koi fish. Unclean water quality, food deterioration, trauma and obvious changes in water quality are all easy to cause this disease.

(3) Prevention and control methods:

A, pay attention to the reasonable feeding density, usually keep the dissolved oxygen in the water at 5 mg/L. Strengthen feeding management, feed more bait rich in protein, and enhance the resistance of fish. Avoid hurting fish in fishing and other operations.

B, put the sick fish into a medical fish tank, and soak the sick fish in 5 mg/L nitrofurazone solution for about 30 minutes, once a day/kloc-0, and the water temperature is the same as that of the original cultured water body until the condition improves. In addition, the original aquarium or fish pond can be disinfected with 0.2% crude salt solution.

C, soak the sick fish with penicillin sodium or technetium potassium, with the dosage of technetium toxin of 4-8 million units/m3 for 30 minutes every day until the condition improves.

D, bleaching powder is directly added into the fish pond where koi fish is raised, so that the water body is 1mg/L, and the sick fish are soaked for 4-6 days. After the condition improves, gradually change the pool water into clear water. (1) Symptoms: The skin is inflamed and congested, which is most common around the orbit, gill cover, abdomen and tail stalk. Sometimes there is congestion at the root of each fin, and in severe cases, the fins are broken. After dissection, we can see that the internal organs of fish, such as intestine, kidney and liver, have different degrees of inflammation and congestion. Sick fish float on the surface of water or sink to the bottom of water, swimming slowly, reacting slowly and having poor appetite. The difference between skin inflammation and hyperemia and erythroderma is that when koi fish attacks, the skin is normal, and the scales are usually intact and will not fall off.

(2) Pathogen and cause of infection: It is caused by bacteria, belonging to bacterial diseases, and the specific types of bacteria are unknown. The reason of infection is that the water quality is unclean or the bait deteriorates, which leads to the decrease of fish resistance, and the pathogenic bacteria act on the fish to attack.

(3) Prevention and control methods

A, pay attention to the reasonable feeding density, so that the dissolved oxygen in the water can be maintained at about 5mg/L ... Strengthen feeding management, feed more bait rich in protein, and enhance the resistance of fish.

B, put the sick fish into a medical fish tank, and then soak the sick fish in 5 mg/L nitrofurazone solution for about 30 minutes, and the water temperature is the same as that of the original cultured water body, once a day 1 time, until the condition improves. In addition, the original aquarium or fish pond can be disinfected with 0.2% crude salt solution.

C, soaking the sick fish with penicillin sodium or technetium potassium at a dosage of 4-8 million units/cubic meter for half an hour every day until the condition improves. (1) Symptoms: Every fin has shrunk, so it can't swing against the current, as if it were asleep. In severe cases, koi fish was floating on the water, with dim body color and thin body.

(2) Pathogen and cause of infection: due to improper operation or environmental discomfort.

(3) Prevention and control methods

A, reduce the feeding density, keep the dissolved oxygen in the water at about 5mg/L, strengthen the management of word feeding, raise the water temperature, and feed more bait with high protein content such as red worms and shrimps, so as to increase the resistance of fish.

B, soak the sick fish in the original fish tank (fish pond) with 2 mg/L methylene blue solution until the condition improves.