Albendazole is a benzimidazole derivative with anthelmintic activity. It is the treatment of choice for fasciolosis. The use of albendazole in South American camelids is common, however, there are no studies about the pharmacokinetics and pharmacodynamics of albendazole in alpacas and llamas. In the present study, a case of fiber loss (alopecia) in alpacas is described because of the suspected use of a high dose of albendazole. In a fasciolosis control program of an alpaca ranch located in the district of Nuñoa in Puno, Peru, 2184 alpacas were oral treated with albendazole (35–40 mg/kg). After 2 weeks of treatment the alpacas began to show loss of fiber in the abdomen, flanks and neck. The alpacas showed no other sign of disease. The alpacas recovered their fiber after 6 months. We suggest studies are needed to determine the safe dose of albendazole in alpacas.