¹Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, CA, USA; ²Department of Veterinary Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, CA, USA; 3Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California, Davis, CA, USA; 4Department of Veterinary Clinics and Surgery, School of Veterinary Medicine, University of Minas Gerais, Minas Gerais, Brazil; 5Companion Exotic Animal Medicine and Surgery Service, William T. Pritchard Veterinary Medical Teaching Hospital (VMTH), University of California, Davis, CA, USA; 6Department of Ophthalmology & Vision Science, School of Veterinary Medicine, University of California, Davis, CA, USA
Abstract
Cryosurgery, also known as cryotherapy and cryoablation, is a promising surgical technique that employs highly localized freezing to destroy damaged and diseased tissue, including benign and malignant neoplasms.1-7 This procedure has been reported in the treatment of chromatophoromas, fibromas, and peripheral nerve sheath tumors in piscine patients.8-10 This study presents eight clinical cases of cryosurgery on cyprinid pet fish for a wide array of neoplastic masses including chromatophoromas, squamous cell carcinoma, and sarcomas that were diagnosed by histopathology. Surgical excision of external masses, liquid nitrogen cryotherapy, injectable medications (meloxicam and danofloxacin), and topical medical-grade honey were applied to the patients following biopsy sampling. Five out of seven cutaneous cases and two out of three ocular cases had complete resolution without recurrence for at least three months post-treatment. Treatment was unsuccessful for two of the cutaneous cases in which the cutaneous masses were extremely invasive, resulting in severe ulceration and deep invasion into the coelomic cavity. One of the ocular cases involved a corneal mass that did not change in size and had no complications after treatments, suggesting that the treatment might be useful in limiting growth. In conclusion, the effectiveness of cryotherapy appears to correlate with the tumor type, as well as the stage and progression of tumor invasion.
Acknowledgements
The authors thank the financial support of the University of California—Davis (UC Davis) Aquatic Animal Health Fellowship partners (UC Davis Veterinary Medical Teaching Hospital, California Academy of Sciences—Steinhart Aquarium, Monterey Bay Aquarium and Hubbs Seaworld Research Institute). The authors also thank the rescuers of the California Camp Fire and the staff at the Center for Aquatic Biology and Aquaculture—UC Davis.
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