What are the most common goldfish diseases?

* Aeromonas - A bacterial infection that causes skin lesions, ulcers, and septicemia.

* Columnaris - A bacterial infection that causes saddleback lesions, mouth rot, and tail rot.

* Fin rot - A bacterial infection that causes the fins to become ragged and frayed.

* Dropsy - A bacterial infection that causes the fish's body to swell with fluid.

* Ich - A parasitic infection that causes small white spots on the fish's body.

* Velvet - A parasitic infection that causes a gold or brown velvety coating on the fish's body.

* Gill flukes - A parasitic infection that causes the fish to have difficulty breathing and may cause the gills to become pale or red.

* Tapeworms - A parasitic infection that causes the fish to have weight loss, diarrhea, and a bloated abdomen.

Fungal Infections

* Saprolegnia - A fungal infection that causes cottony white growth on the fish's body.

* Achlya - A fungal infection that causes brown or black lesions on the fish's body.

Viral Infections

* Lymphocystis - A viral infection that causes warty growths on the fish's body.

* Spring viremia of carp (SVC) - A viral infection that causes the fish to have internal bleeding, skin ulcers, and septicemia.

Nutritional Deficiencies

* Vitamin C deficiency - A vitamin C deficiency can cause the fish to have a weakened immune system, poor growth, and skeletal deformities.

* Vitamin A deficiency - A vitamin A deficiency can cause the fish to have night blindness, poor growth, and skin lesions.

* Protein deficiency - A protein deficiency can cause the fish to have poor growth, a weakened immune system, and fatty liver disease.

Environmental Problems

* Poor water quality - Poor water quality can cause the fish to have stress, disease, and even death.

* High temperature - High temperature can cause the fish to have heat stress, which can lead to disease and death.

* Low temperature - Low temperature can cause the fish to have cold stress, which can lead to disease and death.

* Sudden changes in water temperature - Sudden changes in water temperature can cause the fish to have stress, which can lead to disease and death.

* Chemical poisoning - Chemical poisoning can cause the fish to have a variety of health problems, including disease and death.