Cirugia en peces

Fish Surgery
MichaelJ. Murray, DVM

As the number and value of captive fishes increases, so too will the indications for surgical intervention by the veterinarian. In general, the most difficult aspect of fish surgery is the provision of adequate and safe anesthesia, and several different anesthetic regimens are provided. Once one is familiar with the normal anatomy of the piscine patient, thebasic concepts of surgery prevail, including appropriate surgical approach, hemostasis, and gentle tissue manipulation. Specific surgical procedures, celiotomy, liver biopsy, renal biopsy, and laparoscopy are discussed. Finally, successful outcome of a surgical manipulation often rests in the postoperative management of the surgical patient. Suggestions for appropriate postoperative managementare also discussed. Copyright 2002, Elsevier Science (USA). All rights reserved. Key words: Fish, surgery, anesthesia, laparoscopy, celiotomy, biopsy.

increased. Public aquaria have increased in b o t h n u m b e r and complexity and often exhibit fish with substantial financial and genetic value. As a result, advances in fish surgery have b e c o m e commonplace. A n u m b e r of excellentreviews of surgery in the piscine patient have b e e n published recently in the veterinary literature. 1,2 Much of the earliest work published was directed towards and written by fish pathologists and biologists with particular emphasis on diagnostic sample collection and transmitter implantation. ~-7 An a t t e m p t will be m a d e within this review to present a m o r e traditional veterinary a p pr o a c h to fish surgery that includes discussion of anesthesia, patient preparation, instrumentation, surgical procedures, and postoperative m a n a g e m e n t .

g g V o u can do that?" is probably one of the At most c o m m o n l y e n c o u n t e r e d responses to clinicians advocating a surgical m a n i p u l a t i o n of a piscine patient. O n the surface, one should not be terriblysurprised at such a response; however, one n e e d only look m o r e carefully at the demographics associated with captive fish to u n d e r s t a n d some of the driving forces b e h i n d "pet" fish medicine. Although the exact numbers are difficult to ascertain, the results of the 2001 p e t ownership survey posted on the American Pet Product Manufacturers Association Web site indicate that thereare approximately 160 million pet fish. Many of these fish are dear pets to their owners, a n d the h u m a n - a n i m a l b o n d definitely influences the level of veterinary care expected. As life support systems for captive fish have i m p r o v e d and decreased in cost, b o t h the value and longevity of m a n y specimens has

Anesthesia
Debate still occurs regarding the ability of fishto feel pain. W h e t h e r or not they feel pain, it is i n c u m b e n t u p o n the veterinarian to err on the side of caution, assume pain can be experienced, and offer anesthesia during painful procedures (Table 1). T h e r e can be no doubt, however, regarding the often violent reaction that fish have to noxious stimuli. O n e must always recognize the potential for idiosyncratic problemswith anesthetics in fish. For that reason, there are circumstances in which painless procedures, such as skin scrapings, may be carried out with gentle physical restraint. This does not imply, however, that physical restraint is appropriate for procedures that may be painful to the fish. Many elasmobranches are adequately sedated following immersion in a water column that is supersaturated withoxygen. Still other species may be adequately immobilized by physically holding t h e m in dorsal r e c u m b e n c y via a process of tonic immobility. This practice should be used with caution because some species may experience adverse effects to e x t e n d e d periods of tonic immobility.

From the Monterey Bay Aquarium, Monterey, California. Address correspondence to Michael J. Murray DVM,...