Mortality associated with melarsomine dihydrochloride administration in two North American river otters (Lontra canadensis) and a red panda (Ailurus fulgens fulgens).
Two adult North American river otters (Lontra canadensis) and an adult red panda (Ailurus fulgens fulgens) at three separate institutions died within 22 hr after receiving single 2.5- to 2.7-mg/kg doses of melarsomine dihydrochloride administered in the epaxial musculature as a treatment for filarid nematodes. One otter had a suspected Dirofilaria immitis infection, the other had a confirmed D. lutrae infection, and the red panda had a confirmed Dirofilaria sp. infection, presumably with D. immitis. Postmortem examinations revealed similar gross lesions, although they were less severe in the red panda. The trachea and primary bronchi contained abundant foamy fluid, the lungs were mottled with areas of consolidation, and the pulmonary parenchyma exuded abundant fluid at the cut section. Histologic evaluation revealed acute pulmonary edema, which resulted in respiratory failure and death. There may have been direct pulmonary cellular toxicity of melarsomine dihydrochloride or a severe systemic anaphylactic reaction to antigens released after parasite death. An idiosyncratic drug reaction or a low therapeutic index of melarsomine probably caused the death of the three individuals. Melarsomine dihydrochloride use should be avoided in North American river otters and red pandas.
Neiffer
Donald L
DL
Pittsburgh Zoo, Pennsylvania 15206-1178, USA.
Klein
Edwin C
EC
Calle
Paul P
PP
Linn
Michael
M
Terrell
Scott P
SP
Walker
Rodney L
RL
Todd
Donna
D
Vice
Carol C
CC
Marks
Steven K
SK
D000818:Animals; D000836:Animals, Zoo; D001152:Arsenicals / Q000627:therapeutic use; D002335:Carnivora / Q000469:parasitology*; D004184:Dirofilariasis / Q000188:drug therapy*; D005260:Female; D005369:Filaricides / Q000506:poisoning* / Q000627:therapeutic use; D008168:Lung / Q000187:drug effects / Q000473:pathology; D008297:Male; D010041:Otters / Q000469:parasitology*; D011041:Poisoning / Q000473:pathology / Q000662:veterinary; D014227:Triazines / Q000506:poisoning* / Q000627:therapeutic use
D001152:Arsenicals; D005369:Filaricides; D014227:Triazines; C076253:melarsomine