MySheen

Infectious pancreatic necrosis of salmon and trout

Published: 2024-11-22 Author: mysheen
Last Updated: 2024/11/22, The pathogen is infectious pancreatic necrotic disease virus. Vertical transmission: eggs and semen of parent fish with virus; horizontal transmission: feces, urine and secretions of diseased fish bring the virus into the water, the route of infection is Gill and mouth. Most of the juvenile fish with symptom weight more than 5 grams are chronic, the speed of death is slow, the appearance of abdominal swelling, blackening of body color, exophthalmos, hyperemia and redness of fin base and abdomen, anus mostly dragging linear feces, slow swimming and poor feeding. Most of the fry weighing less than 5 grams are acute, the rate of death is fast, and the activity of diseased fish is slow.

The pathogen is infectious pancreatic necrotic disease virus.

Vertical transmission: eggs and semen of parent fish with virus; horizontal transmission: feces, urine and secretions of diseased fish bring the virus into the water, the route of infection is Gill and mouth.

Most of the juvenile fish with symptom weight more than 5 grams are chronic, the speed of death is slow, the appearance of abdominal swelling, blackening of body color, exophthalmos, hyperemia and redness of fin base and abdomen, anus mostly dragging linear feces, slow swimming and poor feeding. Most of the fry weighing less than 5 grams are acute, the speed of death is fast, the activity of diseased fish is slow, the bottom sinks after swimming sideways or slowly, the abdomen expands, and the body color turns black.

The epidemic and harm of the disease mainly harms the fry and larvae of salmon fishes. 2-month-old seedlings often cause acute mass death, generally 7 weeks after feeding began to die, larger fry first disease, more than 20-week-old young fish generally no longer disease. The water temperature of the disease is 10 ℃ ~ 15 ℃, and the mortality rate can reach 80% ~ 100% when the water temperature is 10 ℃ ~ 12 ℃. The incubation period of the disease is related to fish size and water temperature. The bigger the fish, the longer the incubation period, and the higher the water temperature, the shorter the incubation period.

Prevent the reproduction of larvae of parent fish without pathogens, do not transport fish and eggs from the affected areas, use independent water bodies for spawning, hatching and culture, fish fry and fry should be placed in the upstream of fishing grounds to prevent horizontal transmission, prevent water pollution, disinfect sick and dead fish in time, thoroughly disinfect fish facilities and tools with high concentration of chlorine, and disinfect fish eggs with polyvinylpyrrolidone iodine 50 mg / L for 15 minutes.

The treatment pool generally controls the development of the disease by raising the water temperature.

 
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