Therapeutic efficacy of halofuginone and spiramycin treatment against Cryptosporidium serpentis (Apicomplexa: Cryptosporidiidae) infections in captive snakes.

The therapeutic effect of halofuginone hydrobromide (Steronol) and spiramycin solubilized (Spirasol) applied to clinical Cryptosporidium serpentis infections in captive snakes was investigated. Pathological changes induced by C. serpentis were typical for snake cryptosporidiosis. Spiramycin induced no significant change in the pattern of shedding of fecal Cryptosporidium oocysts; biopsies and necropsies revealed cryptosporidiosis in gastric mucosa of all spiramycin-treated animals. In all, 8 of 21 (38%) halofuginone-treated snakes stopped shedding C. serpentis oocysts; examination of gastric tissue of 6 of these 8 animals revealed cryptosporidiosis in 2 snakes. Hepatotoxic and nephrotoxic pathological changes induced by halofuginone included focal or multifocal, severe, acute liver necrosis; severe liver hemosiderosis; and bilateral, severe, acute diffuse cortical and tubular necrosis and iron deposition. Postprandial regurgitation associated with midbody swelling, observed in 4 halofuginone-treated and 2 spiramycin-treated snakes at 15 and 21 weeks after drug withdrawal, did not coincide with oocyst-positive feces. Neither halofuginone nor spiramycin treatment produced a satisfactory therapeutic outcome when applied against clinical C. serpentis infections in snakes.