A 7 ft 2 in, 163 lb female tiger shark (Galeacerdo cuvier) had a history of abrasions on its dorsal fin due to scraping exhibit rock work. The animal was transferred to a new exhibit to prevent further abrasions and a course of enrofloxacin was started. A few months later, the shark started intermittently exhibiting abnormal swimming behavior consisting of holding its head above and tail below the horizontal plane. The shark was given several more rounds of enrofloxacin. When the shark became anorexic for 1 week, the veterinarian was notified and a physical examination was performed.
On physical exam, the animal was extremely cachectic, had exposed cartilage on the cranial edge of the dorsal fin, and the edges of the pelvic, caudal, and anal fins, and had severe ventral abrasions. Hematology and serum chemistries appeared to be within normal limits. The blood culture produced enrofloxacin resistant Staphylococcus cohnii. A fecal wash collected a small amount of stool in which no parasites were present. Vitamin E, vitamin B complex, ceftiofur sodium, and prednisolone sodium succinate were administered. The animal continued to deteriorate the following day and methylprednisolone acetate and oxygen therapy were given. The next morning, the animal was hyporesponsive, and euthanasia with MS-222 and quinaldine sulfate was elected.
At necropsy, a sterile cerebral spinal fluid tap was performed. The fluid was clear, transparent, of moderate tenacity, and contained a few pieces of white flocculent material, crystals, and other nondescript debris. Culture of the fluid produced enrofloxacin resistant Streptococcus acidominimus. The GI tract was devoid of food, and the colon contained numerous tapeworms. Histopathology revealed meningoencephalitis and nephritis, as well as branchitis, gastritis, and coelomitis associated with parasitism.