Abstract
Within the last 10 years toxoplasmosis has been more prevalent in cetaceans. This disease is typically seen in land mammals that come in contact with feline feces. When this disease does occur in marine mammals, it usually does so in young or immunosuppressed animals.2 It is unknown how wild marine mammals contract this disease, but there are several theories. In animals in human care, it is believed to result from stray cats defecating around the dolphin habitat.1
Case 1
In July of 2009, an adolescent male bottlenose dolphin in human care presented with anorexia and lethargy. This animal had stranded in 2006 as a yearling and had a history of kidney stones, and was on medications for the stones. The animal had a decreased serum iron 73 µg/dL, increased erythrocyte sedimentation rate 22 mm/h (normal 5–7 mm/h) with a white blood cell count of 9800 cells/µl. Various diagnostic tests were performed. Pending test results, the animal was prophylactically placed on antifungals and antibiotics. A toxoplasmosis titer was elevated and the dolphin was prescribed clindamycin. Previous toxoplasmosis titers were negative. Within one week, the animal began eating again and became more energetic. He continued to receive clindamycin until clinical signs resolved.
Case 2
A female Rough-toothed dolphin stranded in October 2009 at approximately two years of age and was taken to the same facility as the male in Case 1. Upon initial intake into rehabilitation, blood was taken for various diagnostic tests including a toxoplasmosis titer. The toxoplasmosis titer measured 1:128 and so the animal was placed on clindamycin. She recovered with no significant problems; however, she always had pruritic skin. In December of 2011, she began to exhibit clinical signs similar to those displayed by the male in Case 1. A toxoplasmosis titer was performed and was low; however, lab error was suspected. Serum had been banked several times since her arrival at the facility and so multiple samples were re-sent for toxoplasmosis titers. This time all samples, including the sample taken upon her arrival, measured >1:512. She was prescribed clindamycin and her clinical signs improved.
Both animals continue to have static but higher than normal titers to toxoplasmosis. Throughout this time, no other animals at the facility have exhibited similar clinical signs and toxoplasmosis titers performed have all been < 1:32.
Acknowledgements
The authors would like to thank the entire marine mammal department at Gulf World Marine Park for the outstanding care they continue to provide to their animals.
References
1. Dubey JP, Mergl J, Gehring E, Sundar N, Velmurugan GV, Kwok Och, Grigg Me, Su C, Martineau D. Toxoplasmosis in captive dolphins (Tursiops truncatus) and walrus (Odobenus rosmarus). J Parasitol. 2009;95(1):82–85.
2. Dubey JP, Zarnke R, Thomas NJ, Wong Sk, Van Bonn W, Briggs M, Davis JW, Ewing Mense M, Kwok Och, Romand S, Thulliez P. Toxoplasma gondii, Neospora caninum, Sarcocystis neurona, and Sarcocystis canis-like infections in marine mammals. Vet Parasitol. 2003;116:275–296.