A 31-year-old female Atlantic Bottlenose dolphin (Tursiops truncatus) developed Zygomycosis in November of 2005. This female had been rescued from Marinelife in Gulfport, Mississippi a day after Hurricane Katrina and was transported along with 5 other dolphins to Gulfarium in Fort Walton Beach, Florida. For 10 weeks this dolphin had normal blood tests with no clinical signs of illness. The first indication of disease was partial anorexia.
Within 48 hours she became totally anorexic and the blood tests revealed an elevated erythrocyte sedimentation rate of 120mm/hr with a slight increase of the white blood cell count. The renal values were slightly elevated. Two characteristic eschar lesions were found on examination, one on the left thoracic side and the other on the left peduncle. The lesions were surgically excised for both treatment and definitive diagnosis of Apophymyces elegans. The histopathologic study revealed numerous hyphal organisms consistent with a zygomycetes infection. She was placed on Posaconazole, a new azole made by Schering-Plough at 5mg/kg PO BID. Definitive diagnosis of A. elegans was provided by the Fungus Testing Laboratory in San Antonio, TX. Sensitivity for posaconazole was performed but the organism failed to grow in the testing system.
The renal values continued to increase with the highest levels being a BUN of 88 mg/dL and creatinine of 7.6 mg/dL with a urine specific gravity of 1.020. It was suspected that there were renal infarcts from the fungus causing the acute renal disease. Two liters of LRS were administered subcutaneously once a day as well as six liters of oral fluids. Over the next two weeks these values returned to normal.
For the first month her appetite remained poor, averaging only 5 pounds of fish/day. She was supplemented with a fish gruel administered via a stomach tube. On December 13, 2005 trainers noted her drinking salt water and her serum sodium was 193mEq/L and the serum chloride was 155 mEq/L, with no change in the total serum proteins or hematocrit. The salinity of the pool was reduced from 32ppt to 18ppt by the addition of fresh water to the pool. She was also given 3L of oral water twice a day. Cerebral edema was suspected during this time when the trainers noted that the animal did not appear to be able to see them and would hit her rostrum against the walls of the pool. The sodium and chloride decreased over the next few days and her neurological signs resolved.
A few days after the serum electrolytes improved her serum calcium and phosphorous levels started to decrease. Oral calcium, phosphorous, and vitamin D were given three times a day. The serum calcium levels decreased to as low as 5mg/dL and a phosphorous as low as 0.5mg/dL. Concurrently, her WBC increased to 30,400 with WBC in the gastric sample. Pneumonia was the primary rule out. Cultures from a chuff sample revealed Aeromonas hydrophilia, E. coli, and Staphlococcus sp. She was placed on appropriate antibiotics and the WBC returned to normal.
The treatment of zygomycosis requires a high index of suspicion of this disease in endemic areas followed by aggressive surgical and medical intervention. The surgical excision of the obvious lesions and the use of posaconazole was successful in treating this case of A. elegans in a bottlenose dolphin.
The authors wish to thank Schering-Plough for supplying the posaconazole, and the FDA for the prompt compassionate need approval for the use of posaconazole. The Texas Fungal Lab, Annette Fothergill, Diane Sutton and Dr. Rinaldi, for all their help. A special thanks to Marci Romagnoli, Liz Sack, and the staff at the Gulfarium for their care of this animal during her illness.