Streptococcus disease strikes Tilapia is highly disease-resistant, and fish diseases are rarely seen. As long as we adhere to the principle of prevention first, clean the pond and disinfect the fry before putting the fry into the pond, there will be no fish disease. If there is fish disease, most of it is caused by bacterial infection due to transportation or fishing scratches, especially when the weather is cold, it is easy to be infected with saprolegnia after transportation. The pool can be splashed. When using external spray medicine and oral fish medicine, it should comply with the "Guidelines for the Use of Pollution-free Food and Fishing Drugs"