Abstract

Managed moray eels (Muraenidae) are known to develop severe elevations in triglyceride and cholesterol levels as compared to their wild counter parts.^1-3 Morays are also known to develop diseases associated with alerted lipid metabolism such as lipid keratopathies and xanthomas.^2,4,5 Causes of altered lipid metabolism have not been definitively proven; however, they are suspected to be due to managed diets having higher fat or cholesterol content as compared to wild diets.^1-4

In December of 2019, a >7-year-old adult, female California moray eel (Gymnothorax mordax) presented for a mass on the dorsum of the head measuring approximately 10 cm x 7 cm. This eel had a previous history of a xanthoma in this location that was incompletely excised in 2017. Minimal recurrence of the mass had been appreciated until two months prior to re-presentation when the mass had begun growing rapidly in size. Surgical management was once again elected, and the mass was bluntly and sharply dissected away from the skull and musculature of the dorsum of the head. Incomplete surgical resection was once again achieved due to the extensive nature of the mass. The incision was closed using 2-0 polydioxanone utilizing a mixture of cruciate and simple interrupted sutures. Histologic analysis of the mass was once again consistent with a xanthoma.

Management of the post-operative incision site was challenging over the course of the next three months due to repeated ciliate, flagellate and bacterial infections of the incision despite treatment with a variety of antibiotics, anti-inflammatory, and anti-parasitic medications. Approximately three weeks after the initial surgery, a second incision revision surgery was performed due to poor healing. Two months after this incision revision procedure, the sutures were removed as it has been shown that fish can have a severe inflammatory reaction to suture material,⁶ and it was postulated that this may have been the cause of poor wound healing. Unfortunately, this led to complete dehiscence of the incision with insufficient viable skin to perform closure over the skull.

At this time, an autogenous skin graft was performed to allow for closure of the wound defect. A 6 cm x 4 cm full-thickness piece of skin was harvested from the right dorsal flank of the eel. The skin on the dorsum of the head was trimmed back as much as allowable to achieve healthy bleeding edges. The graft was then sutured in place on top of the head using a combination of simple continuous, cruciate and simple interrupted sutures using 2-0 polydioxanone. The skin surrounding the harvest site was then undermined and closed from the corners towards the center creating an X-shaped suture line.

Over the course of the next 10 months both the skin graft and harvest site incisions healed slowly but progressively, though intensive medical management was still required for the first five months following the graft surgery. To the author’s knowledge, this is the first report of an autogenous skin graft used for wound closure in a teleost species.

Acknowledgements

The author wishes to thank the veterinary technicians and aquatics staff of the California Science Center for their dedicated care of this patient. The author would also like to thank Dr. Jamie Gerlach for her help with the tumor resection surgery and Dr. Mike Garner of Northwest ZooPath for the histologic analysis of this case.

*Presenting author

Literature Cited

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