The most important pathologies that can suffer tetra fish are parasites. Especially the parasite known as Pleistophora hyphessobryconis. It is a disease that affects the digestive organ of the fish. This parasite rarely affects other species that inhabit the aquarium. They are specific parasites that mainly affect tetra.
However, it may be that this pathology, although it is directly related to tetra, there are other species of Characids and Cyprinids that develop similar diseases although the responsible parasite is different in each case.
Pathology
If we talk about a mild condition, we will hardly notice anything abnormal in the fish. We speak of a chronic infection when cause discoloration, especially in the red stripes of the neons. Symptoms are erratic swimming, curvatures in the spine, thinness, and bacterial rot in the fins as a result of loss of defenses.
As it is a pathology that begins from the digestive system, this causes a gradual decrease in energy resources and defenses as a consequence is the appearance of multiple bacterial pathologies and infections. It is recommended that fish that are infected be removed to another aquarium. Since the spores of these parasites can survive for a time in the aquarium where the infected fish has been.
Treatment
Curing the Pleistophora parasite is not entirely effective. It can be treated by compounds known as furazolidone. Although there are not many references that it is effective against this parasite. But it is effective in avoiding side effects.
The most effective is the quarantine of the infected tetra. The use of germicidal lamps is recommended for the parasite-free swimming phase but not for internal infections. They mostly have a very high mortality rate. Be very careful when they can die and not remain in the aquarium because the rest of the fish could become infected.