Detailed Explanation of Symptom Identification and Prevention and Treatment Methods for Fish Liver and Gallbladder Lesions

Fish viral diseases, bacterial diseases, nutritional metabolic diseases, water pollution, and long-term high-dose use of the same antibacterial drug can all cause lesions in the fish liver and gallbladder. In particular, second-year grass carp (Ctenopharyngodon idella) have a relatively high chance of contracting this disease, which often causes huge economic losses to aquaculture farmers.

1. Symptoms

After fish contract liver and gallbladder disease, their external appearance is usually normal, and the main problems occur in the internal organs. The main symptoms are as follows:

1. Color changes. The liver appears white, pink, earthy yellow, yellow-brown, purple-black, or with red and yellow intercrossing, and may even turn green.

2. Pathological changes. Swelling, edema, atrophy, or becoming reticular; there are white granules in the liver tissue, or the liver resembles tofu dregs.

3. There are hemorrhagic spots on the liver, cirrhosis occurs, and the spleen is enlarged with hemorrhagic spots.

4. The gallbladder becomes enlarged, and the bile changes from normal green to black; in some cases, the gallbladder becomes smaller or atrophies.

2. Prevention and Treatment Methods

First, a correct diagnosis should be made of what cause has led to the lesions of fish liver and gallbladder disease, and then drugs should be selected in a targeted way for treatment.

1. The occurrence of this disease is usually related to feed. Before feeding medicated bait, the feed formula should be changed, and a nutritionally balanced complete feed should be selected for feeding, which helps treatment.

2. If the occurrence of liver and gallbladder disease is accompanied by external diseases, such as gill rot and red skin disease, please use external disinfectants according to the symptoms.

3. For the treatment of liver and gallbladder lesions, oral medication is recommended. For oral medication, compound Chinese herbal medicines and similar drugs should be selected. Drugs such as Sanhuang Powder, Huanglian Jiedu San, and Baoganling should be added and mixed into the feed according to the package instructions. When the condition is severe, the dose may be increased, 1 to 2 times per day, for 5 to 7 consecutive days of feeding. Because these compound Chinese herbal medicines have the effects of clearing heat and detoxifying, stopping bleeding, and regulating the body, and do not cause drug resistance, their therapeutic effect is relatively obvious. The author recently used the above method to successfully cure 2 cases of grass carp liver and gallbladder disease, recovering certain economic losses for aquaculture farmers.