1. Reason: The festering of guppies may be due to poor water quality. Although they do not have high requirements for water quality, if the water quality is too poor, it is easy to breed bacteria and lead to decay.

2, Solution: Breeders need to change their water immediately, which can reduce the risk of reinfection. They should also add some crude salt to the fish tank where they live, which can inhibit the growth of bacteria.

1. Reason: The ulceration of guppies may also be caused by infection due to lack of timely treatment after trauma. Their skin is fragile. If there are sharp objects in the fish tank, it is easy to scratch them. If the scratch is not treated in time, the wound will be infected, inflamed and rotted.

2. Solution: If the rotten parts are serious, the breeder needs to clean up the rotten meat first. Then apply potassium permanganate to the affected area, which can speed up their recovery and prevent the wound from deteriorating again.

1. Reason: Guppies may also suffer from white spot disease. Although white spot disease can't cause them to fester in the early stage, it will fester in the later stage.

2. Solution: Breeders need to raise the water temperature to 28-30 ℃ first, and then give them a medicated bath with white spots. The specific dosage is best decided according to their condition. After about 3-5 days of medicated bath, the festering parts of guppy will improve.