Rhabdiasis, caused by the lungworm
Rhabdias sp, commonly causes pulmonary damage and secondary infections in captive amphibians. This nematode has a direct life cycle with free-living phases. Adult worms live in the lungs, where they deposit larvated eggs that are coughed up, swallowed, and then excreted into the environment. Infective L3 larvae then burrow through the skin of a new host, where they mature and migrate to the lungs. Affected animals may appear anorectic, thin, and generally debilitated. A premortem diagnosis may be made by finding ova or worms in oral and nasal secretions. Infection should be suspected when nematode larva and larvated eggs are found in fresh feces from an animal with clinical signs. When rhabdiasis is suspected, treatment using fenbendazole (100 mg/kg/day, PO, for 2 days then repeated 12–14 days later) or ivermectin (200–400 mcg/kg, PO, once, repeated 12–14 days later) is recommended. After the second of each 2-day fenbendazole treatment or each dose of ivermectin, the animals should be moved into a newly established environment to prevent reinfection from free-living life stages. Some reactions to fenbendazole have been reported, so animals should be monitored closely and treatment discontinued if necessary.
Infectious Diseases of Amphibians: Amphibians: Merck Veterinary Manual