Abstract
Fusarium sp. exists in soil and water worldwide, and may occasionally cause opportunistic infection in animals.1 Some Fusarium species have been reported to cause invasive infection in immunocompromised human patients.1 Two female common seals (Phoca vitulina) had suffered from onychomycosis since 2013 in Farglory Ocean Park, Taiwan, and one of them had multifocal skin lesion. The nail and skin lesions generally became worse during summer time and before molting season every year. Biopsied samples were collected from nail and skin lesions for several times, and Fusarium solani was isolated repeatedly. Different antifungal treatments, including terbinafine, fluconazole, and itraconazole by oral administration and topical ketoconazole, were applied in these diseased seals, but no significant improvement was noted. Since March 2016, the seals were treated with topical thiabendazole spray by following the protocol published in a previous study.2 The spray contained the mixture of 10.86 g of thiabendazole powder suspended in 100 ml of water to 2 parts of propylene glycol. The wounds around the nails almost healed completely after 2 months, and no fungus can be isolated from all the nails and skin after 5 months. There are some possible contributing factors for the Fusarium solani infection in these seals. First, the affected seals were kept in an outside pool. The temperatures of pool and air would usually increase to 23–25°C and 36–38°C in summer time, respectively. Such high air/water temperatures may not only increase the growth rate of Fusarium solani, but also cause stress to the seals. In addition, the seals had lived with many California sea lions, and such phenomenon may be stressful for the seals as well. It's speculated these stressors can compromise their immune function, and hence the Fusarium solani may establish the opportunistic infection. When the "thiabendazole spray" treatment started, the seals were moved to an isolated indoor medical pool with the elevating platform and central air-conditioning system. The trainer can use the spray on the nail and skin lesions for many times a day without interference by other animals or any training process. Furthermore, the growth of Fusarium solani may be inhibited by the decreased air/water temperatures.3 In summary, low-stress environment and appropriate medical care applied in the seals with Fusarium solani infection are the key successful factors in our cases.
Acknowledgements
The authors would like to thank Dr. Wen-Ta Li of the National Taiwan University-School of Veterinary Medicine/Graduate Institute of Molecular and Comparative Pathobiology, Dr. Wei-Chang Yang of the National Chiayi University-Department of Veterinary Medicine for their suggestions on this case, and all the trainers of Farglory Ocean Park for taking very good care of these two seals.
* Presenting author
Literature Cited
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2. Montali RJ, Bush M, Strandberg JD, Janssen DL, Boness DJ, Whitla JC. 1981. Cyclic dermatitis associated with Fusarium sp. infection in pinnipeds. J Am Vet Med Assoc. 179:1198–1202.
3. Naples LM, Poll CP, Berzins IK. 2012. Successful treatment of a severe case of fusariomycosis in a beluga whale (Delphinapterus leucas leucas). J Zoo Wildl Med. 43:596–602.