Orandas with Pimples in Their Caps

Orandas with Pimples in Their Caps

Many hobbyists report the development of pimples in the head growth (wen) of their prized Orandas. The Orandas and other capped fishes will appear bright, alert, and feeding, yet these tufty whitish patches can appear, and they resemble pimples.

They are GENERALLY not a cause for concern.

For whatever, reason, the fishes’ white blood cells are attracted to the creases in the head growth, especially when it is rapdily developing. When the material is swabbed out and viewed microscopically, it is usually an aseptic collection of white cells.

Wen or Orandas cap pimples
Wen or Oranda cap pimples are collections of white cells.

Sometimes, the lesions can worsen, and the HALLMARK here is that the lesions become reddened. They may start to erode. When and if this happens, it MATTERS, and you are well advised to either inject the Goldfish with an antibiotic, or bathe it in several of the better bath antibiotics – two favorites of mine are Furazone Green, and Trimethoprim Sulfa.

Anytime you see white spots in the crevices of the Oranda’s wen or cap, it’s time to test your water quality, especially for nitrates. Also, increase aeration. It never hurts to do a partial water change, or institute a trickle system.

Orandas with White Spots in Their Wen

Trimethoprim Sulfa, available from your local Veterinarian, may be safely employed as a bath for bacterially infected fish. It has the advantages of being cheap, safe for the fish, safe for you to handle, and is well absorbed through the fishes gills an skin.

Use 960 mg powdered and dissolved per 10 gallons as a bath for 6-8 hours daily.

The effects on the filter bacteria are unknown (to me) which is why I recommend doing this in a warmed (75deg) hospital or remote system.
It is advised that you make up a fresh bath daily, using fish tank water if possible, as potency of the drug after 12-24 hours cannot be assured.  Usually, 3-4 baths are required for cure. Injections are more effective but hardly as practical for the average hobbyist.

Furazone Green (Now all we have is Furan-2) is a potent mixture of powerful antibiotics with decent absorption by the fish, and reasonable tissue penetration. It’s success rate speaks for itself, and I feel that this water bath treatment is the best second-place to actual injection of antibiotics to the fish..

You would simply use the Furan-2 in a known/measured quantity of tank water with some aeration and support for temperature for 6-8 hours a day. Follow label instructions

After an initial short-stumble, the filter will function normally through this medication in the water. You should be aware that UV radiation, either from the sun or from a sterilizer, will neutralize the active ingredients. The furans are also eventually carcinogenic, which is much more of a concern for folks who use the compounds daily, like retailers or wholesalers.




Dr Erik Johnson is a Marietta, Georgia Veterinarian with a practice in small animal medicine. He graduated from University of Georgia with his Doctorate in 1991. Dr Johnson is the author of several texts on Koi and Pond Fish Health and Disease as well as numerous articles on dog and cat health topics.