28th ANNUAL EASTERN FISH HEALTH WORKSHOP April 21-25, 2003 Treating Cancer In The Teleost Patient Scott Weber1, L. Boerner1, J. Mayer2, J. Mateleska2, C. Weisse3, Z. Matzkin3, and A. Klide3 1New England Aquarium; 2Tufts University; 3University of Pennsylvania, Schools of Veterinary Medicine Fish are regularly used in environmental and chemical testing to detect and study effects of mutagenic pollutants or compounds.  Similar to other vertebrates, a number of different tumors have been isolated and identified in fish. Many of these tumors have been recorded in Harshbarger’s Registry of Tumors in Lower Animals.    Although the significance of tumorogenesis in fish has been primarily of a scientific nature, in the last decade, veterinarians have begun diagnosing and treating cancers in a variety of teleosts.  The following presentation discusses diagnostic and treatment options used in three specific cases: surgical removal of a seminoma in a black sea bass, (Centropristis striata); cryosurgery for squamous cell carcinoma in a kannume (Mormyrus kannume); radiation, surgical, and cryosurgical intervention for a neurofibroma of a goldfish (Carassius auratas).  Diagnostics for these cases included: survey radiography, ultrasonography, positive-contrast radiography, hemotology, blood chemistry analysis, histopathology, and computed tomography. One of the greatest challenges for aquatic animal veterinarians is getting an early and quick diagnosis.  In the absence of other clinical abnormalities or behavioral changes, abdominal masses are difficult to detect until abdominal distension is observed.  Often, when abdominal distension is first observed, tumors have grown substantially in size and may account for up to 35% or more of the animal’s body weight.  Other types of cancer, such as lymphosarcoma, may only be readily detected towards the end stage of metastatic disease.  As more diagnostic modalities are used, modified, and/or adapted for aquatic animal medicine, earlier detection and diagnoses of cancers can be made for fish patients.  Quicker diagnoses afford greater availability and success of other oncologic treatment options, such as chemotherapeutics, surgery, interventional radiology, and radiation therapy.  While surgical procedures are performed more commonly on fish in research, few reports of clinical surgical cases have been described in the literature.  These three cases show that aggressive treatment options are possible in fish and that advances in oncology may be successfully applied in aquatic animal medicine.  Earlier detection and increased case documentation should enhance the future success rate for cancer treatment in teleosts. Return to 28th Annual Eastern Fish Health Workshop Return to Leetown Science Center Home Page