Dietary and Surgical Management of Lipid Keratopathy and Systemic Hyperlipidemia in Captive Moray Eels
IAAAM 2009
Alison Clode1; Craig Harms1; Hap Fatzinger2; Forrest Young3
1North Carolina State University, College of Veterinary Medicine, Raleigh, NC, USA; 2North Carolina Aquarium at Fort Fisher, Kure Beach, NC, USA; 3Dynasty Marine Associates, Inc., Marathon, FL, USA

Abstract

Six green moray (Gymnothorax funebris), three spotted moray (G. moringa) and two reticulate moray (Muraena retifera) eels maintained in captivity for variable periods of time received complete ophthalmic exams under MS-222 anesthesia, measurement of serum triglyceride (TG) and cholesterol (CHO) levels, and dietary evaluation as part of routine physical assessment. Seven of eleven eels (63%) were diagnosed with lipid keratopathy due to the presence of crystalline opacification of the cornea and spectacle with variable vascularization.3,4,9,10 Baseline CHO levels (mean 714 mg/dl, range 198-1313 mg/dl) were elevated relative to normal values extrapolated from other species (<150 mg/dl),2,5-8,11 as well as relative to values from four wild-caught green moray eels (mean 370 mg/dl) in all but two eels. Baseline TG levels (mean 712 mg/dl, range 256-1657 mg/dl) were elevated relative to other species (<300 mg/dl)2,5-8,11 and to wild-caught eels (mean 390 mg/dl). The diet in captivity was composed primarily of mackerel (42.3-48.4% fat) and a combination of squid and smelt (12.7-39.5% fat).1 An attempt to lower plasma lipid levels and decrease ocular lipid deposition was made through gradual implementation of dietary modification to primarily lower-fat squid (8.3-11.4% fat) and capelin (7.0-23.3% fat). Due to the severity of the ocular lesions and impact on feeding ability, surgical removal of the superficial spectacle in both eyes (OU) and superficial cornea in the right eye (OD) was performed in one green moray.4 Histopathologic evaluation of the surgical specimens supported lipid infiltration via identification of presumed intrastromal cholesterol clefts and lipid-filled macrophages. The combination of dietary modification and surgery in this individual led to increased ocular clarity and improved feeding behavior for 11 months of follow-up, at which time the eel died following movement to another aquarium. At the time of death, both eyes were clear and histopathologic evaluation did not identify recurrence of lipid keratopathy as identified at the time of surgery. An additional green moray eel was identified as a surgical candidate due to the degree of corneal opacification, however reevaluation following approximately five weeks of dietary modification indicated marked improvement of ocular clarity, and surgery was therefore not performed. Initial CHO values in this eel of 1004 mg/dl were essentially unchanged at 1018 mg/dl at the five-week time point, while serum TG increased from 774 to 1025 mg/dl over that same time period, which is difficult to reconcile with the clinical improvement. In conclusion, captive moray eels have an apparent predisposition to increased serum TG and CHO, and an associated high prevalence of presumed lipid keratopathy. Surgical removal of lipid deposits in the cornea and spectacle may be indicated in severely affected individuals, while dietary lipid reduction may be an appropriate husbandry consideration for all individuals.

Acknowledgements

We thank the staff at the Fort Fisher Aquarium for their dedication to the care and well-being of the animals examined, and for their expertise in handling the animals. We also wish to thank Brian Gilger, Greg Lewbart, Shane Christian, Damian Launer, and Sandy Machon for assisting in evaluation of individuals at the North Carolina State University College of Veterinary Medicine, and Doug Mader and Kelly Martin at the Marathon Veterinary Hospital, and Scott Moroff at Antech Diagnostics, for processing samples from wild-caught eels.

References

1.  Bernard J.B., and M.E. Allen. 1997. Feeding captive piscivorous animals: nutritional aspects of fish as food. Nutrition Advisory Group Handbook, Fact Sheet 005, 12 pp.

2.  Chen C.Y., G.A. Wooster, R.G. Getchell, P.R. Bowser, and M.B. Timmons. 2003. Blood chemistry of healthy, nephrocalcinosis-affected, and ozone-treated tilapia in a recirculation system, with application of discriminant analysis. Aquaculture 218: 89-102.

3.  Gilger B.C. 2007. Diseases and surgery of the canine cornea and sclera. In: K.N. Gelatt, ed. Veterinary Ophthalmology. Ames, Iowa: Blackwell Publishing; Pp. 690-752.

4.  Greenwell M.G., and S.J. Vainisi. 1994. Surgical management of lipid keratopathy in green moray eels (Gymnothorax funebris). Proc Assoc Reptile Amphib Vet and Am Assoc Zoo Vet; Pp. 155-157.

5.  Guijarro A.I., M.A. Lopez-Patino, M.L. Pinillos, E. Isorna, N. de Pedro, A.L. Alonso-Gomez, M. Alonso-Bedate, and M.J. Delgado. 2003. Seasonal changes in haematology and metabolic resources in the tench. J Fish Biology 62: 803-815.

6.  Hrubec T.C., and S.A. Smith. 2000. Differences between plasma and serum samples for the evaluation of blood chemistry values in rainbow trout, channel catfish, hybrid tilapias, and hybrid striped bass. J Aquatic Anim Health 11: 116-122.

7.  Rehulka J. 2000. Influence of astaxanthin on growth rate, condition, and some blood indices of rainbow trout, Oncorhynchus mykiss. Aquaculture 190: 27-47.

8.  Robaina L., G. Corraze, P. Aguirre, D. Blanc, J.P. Melcion, and S. Kaushik. 1999. Digestibility, postprandial ammonia excretion and selected plasma metabolites in European sea bass (Dicentrarchus labrax) fed pelleted or extruded diets with or without wheat gluten. Aquaculture 179: 45-56.

9.  Russell W.C., D.L. Edwards, E.L. Stair, and D.C. Hubner. 1990. Corneal lipidosis, disseminated xanthomatosis and hypercholesterolemia in Cuban tree frogs. J Zoo Wildl Med 21: 99-104.

10. Shilton C.M., D.A. Smith, G.J. Crawshaw, E. Valdes, C.B. Keller, G.F. Maguire, P.W. Connelly, and J. Atkinson. 2001. Corneal lipid deposition in Cuban tree frogs (Osteopilus septentrionalis) and its relationship to serum lipids: An experimental study. J Zoo Wildl Med 32: 305-319.

11. Stoskopf M. 1993. Clinical pathology of marine tropical fishes. In: M.K. Stoskopf, ed. Fish Medicine. Philadelphia, PA: W.B. Saunders; Pp. 614-617.

 

Speaker Information
(click the speaker's name to view other papers and abstracts submitted by this speaker)

Alison Clode
North Carolina State University
College of Veterinary Medicine
Raleigh, NC, USA


MAIN : Poster : Lipid Keratopathy
Powered By VIN

Friendly Reminder to Our Colleagues: Use of VIN content is limited to personal reference by VIN members. No portion of any VIN content may be copied or distributed without the expressed written permission of VIN.

Clinicians are reminded that you are ultimately responsible for the care of your patients. Any content that concerns treatment of your cases should be deemed recommendations by colleagues for you to consider in your case management decisions. Dosages should be confirmed prior to dispensing medications unfamiliar to you. To better understand the origins and logic behind these policies, and to discuss them with your colleagues, click here.

Images posted by VIN community members and displayed via VIN should not be considered of diagnostic quality and the ultimate interpretation of the images lies with the attending clinician. Suggestions, discussions and interpretation related to posted images are only that -- suggestions and recommendations which may be based upon less than diagnostic quality information.

CONTACT US

777 W. Covell Blvd., Davis, CA 95616

vingram@vin.com

PHONE

  • Toll Free: 800-700-4636
  • From UK: 01-45-222-6154
  • From anywhere: (1)-530-756-4881
  • From Australia: 02-6145-2357
SAID=27