Comprehensive prevention and treatment of hemorrhagic disease of domestic fish

I. the object of harm

Grass carp, crucian carp, mud carp, carp and even silver carp.

Symptoms head, orbit, fin base, fish abdominal punctate or patchy bleeding, Gill bleeding or pale, sometimes ascites, fin end rot.

Third, etiology

1. Fish diseases caused by bacteria are mostly caused by conditional pathogens, which will not occur before the deterioration of the water environment. Only when the various factors in the sediment and water become unsuitable for the survival of the fish, the resistance of the fish is reduced, and the bacteria in the water multiply in large numbers, the fish disease will break out.

2. Due to the long-term feeding of the fish pond, the fish discharged a large amount of feces, in which the incompletely digested organic matter polluted the bottom water, and the bottom of the pond became a hotbed for a large number of bacteria to multiply. After a large number of bacteria decompose organic matter, hydrogen sulfide, nitrite, ammonia nitrogen, methane, carbon dioxide and other toxic and harmful gases to fish accumulate in the water, and the fish live in it for a long time, and their physique will decline. It provides an opportunity for bacterial infection.

IV. Disease prevention measures

1. The author particularly emphasizes that with the improvement of @ # @ 233 skills @, efforts should be made on the word "management", and do not ignore the various small links. Fish diseases must adhere to the principle of "giving priority to prevention, prevention is more important than treatment", careful management and comprehensive prevention and control should be achieved.

2. The "triad vaccine" injection of grass carp fingerling is one of the scientific and effective preventive measures.

3. Clear the pond thoroughly. During the period from the end of each year to February of the following year, the water temperature is low and the growth of fish is restricted. You can use this time to dry the pond to remove excess pond mud. It is best to drain the pond water and expose the bottom of the pond until it turns white and cracks.

4. A few days before the storage of water in the pond, use a large amount of quicklime (block) and sprinkle the whole pond with 100m / mu 150kg of bleach or 10m / 15kg of bleach.

5. The fish should be soaked and disinfected before entering the pond. The commonly used drugs are 3% saline, 1max 10000 potassium permanganate, 2max 10000 formalin and 4max 10000 dysentery, and the bath time depends on the water temperature.

6. Reasonable close culture and mixed culture, make full use of water body and feed, do not carry overloaded fish to the water environment.

7. Use medium and high-grade feed, use less raw materials (raw bran, corn, @ # @ 245kg, yellow powder, etc.) and use less low-grade feed, so as to reduce feces and relieve pond pressure by producing the same amount of fish.

8. It is advocated to pull the net every 20 seconds and 30 days. In the sunny morning and noon, the sediment with a lot of organic matter is stirred to the near surface of the water body, which can not only oxidize part of the organic matter by oxygen in the water, but also fully aerate, and inhibit the reproduction of anaerobic bacteria.

9. Immediately after pulling the net, quicklime should be disinfected with quicklime at a water depth of 15kg / mu or 20kg / mu or other water disinfectants, and quicklime should be recommended for disinfection.

10. In the hot season, new water should be added frequently, or part of the pool water should be replaced.

11. It is recommended to turn on the aerator at noon on a sunny day. Apart from turning on the aerator when rescuing the fish floating head, the aerator is turned on for 2 hours between 12: 00 and 3: 00 on a sunny day, which is also an effective measure to relieve pond pressure and prevent diseases.

12. Pay attention to the hygiene of the pond and try not to discharge unfermented human and animal feces directly into the pond.

13, weed diligently, feed to achieve the "four look", "four fixed" principle, leaving no residue, dead fish should be fished out of the pond, dig deep burial. Fourth, look at the principles: look at the season, look at the weather, look at the color of the water, look at the eating of fish. Four principles: fixed point, timing, quality and quantity.

14. Don't raise a certain kind of fish for many years in order to improve your immunity.

V. Therapeutic methods

1. When fish disease occurs, we should adhere to the policy of "early detection and early treatment". Treatment measures should be taken according to the actual situation to control the expansion of the disease and reduce economic losses.

2. The comprehensive measures of "external elimination and internal administration" should be adopted in the treatment.

3. The treatment has a certain course of treatment and time. Any treatment method that wants to achieve the therapeutic effect through a water body disinfection or internal administration, it is difficult to achieve the ideal effect.

4. Disinfection of water body and sprinkling in the whole pool is one of the effective methods. The general time of medication is about 10:00, which can be used two to three times in a row. The first two times can be used once a day within two days, or once every other day. It can be used for the third time in one to two days after the next medication as appropriate.

5. At present, some water disinfectants can be selected: a, bleaching powder: 0.4 Mir 0.5 kg / mu rice water. B, strong chlorine: 0.15ml 0.25kg / mu of rice water. C, the main ingredient is "dichloride", "trichloride" disinfectant, more trade names, please choose regular factory production, according to the instructions. D, the fourth generation disinfectant, the main ingredient is "chlorine dioxide" disinfectant, the trade name is "Keshuangwang", "Shidujing" and so on. It is generally A, B two bags, A, B separated, respectively dissolved and then mixed to be effective. Quicklime and quicklime should not be used at the same time as the chlorine-containing disinfectants mentioned above. Quicklime 15kg / mu can be used 3 days after the use of chlorine-containing disinfectants to consolidate the curative effect.

6. Taking medicine at the same time, it usually takes 6 days to use sulfonamides, and it takes a long time to use sulfonamides.

7, drug administration method, if most fish eat normally, take half of the daily feed to make bait, in feeding, first feed the unmixed material, and then feed the bait. If the food intake is reduced, all baits can be used, and the administration time should be prolonged as far as possible.

8. The self-made method of bait: the correct production of bait is a measure to ensure that the drug is not wasted and effective treatment. If you use pellet feed, there are two ways to make it: first, dissolve enough medicine into the water, soak the feed for 1 hour, the amount of water should be just submerged feed, wait for full absorption, then hook in the right amount of flour (not too much) outside the bait, wrap the bait to avoid drug loss, just dry a little. The second method is to add the material to the flour paste, the amount of flour is 5% Mel 10% of the feed, apply the flour paste on the feed, and then wrap it with a small amount of flour.

9. Internal administration: a, Oxytetracycline: 5Mel 7g / 100kg fish day. B, sulfonamides: 10mur20g / 100kg fish day. C, norfloxacin (2ml 4g / 100kg fish day) plus enrofloxacin (99% pure agent), 1Mel 2g per 100kg fish day, please use with caution. D, appetizers: yeast tablets, rhubarb, soda tablets and so on. E, traditional Chinese medicine: rhubarb, Radix Isatidis, andrographis andrographis, etc., stir according to 0.5%, 1%. F, can not use a certain drug for a long time, so as not to produce drug resistance. G, the dosage of drugs can be increased moderately on the first day.

VI. points for attention

1. It can be operated according to the farmers' own experience and actual situation, but the weight can not be increased at will.

2. During the period of medication in the water body, we should pay close attention to the activity of the fish and turn on the aerator to prevent anoxic floating head death or drug poisoning.