A Fish Story

"Junior", a 4 1/2 year old Black Moor was presented to the Teaching Hospital at Washington State University for evaluation of a cyst below his eye.

Junior had developed a cyst-like structure beneath his left eye about 6 months prior. The cyst grew to approximately the size of the eye and then ruptured. About 2 months later a black mass was noticed below the eye. Over the next two months the mass grew to almost the size of the eye and the fish started to lose weight, though his appetite was still good.  


"Junior" Junior weighed 62 grams. The mass located below his left eye was about 2 cm. The lens in that eye was luxated (out of normal position).  The scales on his body were slightly uplifted suggesting fluid was accumulating in his belly. When resting he drifted in the water down and to the left.

The mass beneath Junior's eye was suspected to be a melanoma as these tumors occur commonly in fish. Melanomas in fish are not like melanomas in people in that fish melanomas do not tend to spread to other parts of the body. The fluid accumulation in the fish's belly was suspected to be caused by an altered ability to regulate salt and water balance in his body. 


junior's surgery Junior was brought back for surgery 4 days later. Junior was anesthetized using MS-222 (Tricaine) powder dissolved in dechlorinated water. His fins were sprayed with fresh water during the surgery. In order to monitor the effects of anesthesia the movement of the gill flaps and color of the gills were closely observed.

As much of the eye mass as possible was surgically removed. Following surgery, Junior recovered in the aerated hospital tank and went home that evening. He was to be treated with an antibiotic containing bath for 6 days.


For several days after surgery, Junior's owner lifted him to the floating pellets to eat. Yesterday, he started swimming around, eating on his own and his ascites (protuding scales) is subsiding.

The microscopic examination of the tissues that were removed suggested a diagnosis of ciliary body adenocarcimona which is a cancer of a glandular tissue in the eye, rather than melanoma. A second surgery to remove the entire eye is being discussed and the benefits and risks weighed against one another.

posted September 19, 2000

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