Sores on Goldfish

A number of diseases can cause sores and open blisters on a goldfish. Such manifestations result from wound infections due to parasites, bacteria or poor water quality; however, most sores are bacterial and cause stress to a goldfish. Owners should always start by identifying the cause of the problem before applying any type of cure.

  1. Ulcer and Causative Agents

    • Most of the sores appearing on a goldfish are caused by ulcers. A number of elements contribute to ulcers in goldfish: stress, presence of bacteria (pseudomonas and aeromonas), fungus or ectoparasites in water, injury caused by mechanical stress or spawning, overwhelming fish population and subnormal water conditions. By the time the underlying cause is pinpointed and isolated, the sore may already have progressed to a stage needing immediate treatment. Owners should treat the sores immediately, as it can cause further complications and can even infect other fish living in the same tank.

    Onset of Infection

    • Sores usually begin with rash-like manifestations on the back and tail of the fish. Red marks or eruptions eventually lead to sloughing off of scales, which would readily cause tissue exposure and damage. The ulcer gradually gnaws at the exposed tissue and causes deeper damage into the flesh and body, resulting in bleeding or worse.

    Symptomatic Treatment Options

    • Small white spots resembling salt or sugar are signs of parasitic infection, while larger and more mottled blemishes with accompanying greyness or yellowness are bacterial. These can be treated with commercial antibiotics or pure plain salt diffused in water. Golden yellow to brownish sheen is also parasitic and can be treated the same way. Raised spots are caused by fish lice, which have to be taken out manually, with the area treated with antiseptic medications like iodine or hydrogen peroxide. Spawning injury sores do not really need treatment since they disappear on their own. Bacterial sores are concomitant with fluke infections, thus necessitating both antibiotic injections and feeding with medicated nourishment.

    Prevention

    • As soon as infection sets in and manifests itself in the goldfish, check the water condition of your tank. The infected fish needs to be isolated in a hospital tank and ensuing complications should be countered with medicated preparations and medical treatment. To avoid the problem in the future and prevent an outbreak, religiously monitor water condition and always clean the filters. Other preventive measures include regular water changes, avoiding overcrowding, proper tank aeration and immediate medical attention when symptoms appear.