Epidemiology of hookworm (Uncinaria spp.) infection in New Zealand (Hooker's) sea lion (Phocarctos hookeri) pups on Enderby Island, Auckland Islands (New Zealand) during the breeding seasons from 1999/2000 to 2004/2005.

This is the first investigation of the epidemiology of hookworm (Uncinaria spp.) infection in New Zealand sea lions (NZSLs; Phocarctos hookeri) on Enderby Island, Auckland Islands. The examination of faeces for hookworm eggs in various age categories of sea lions revealed that only pups up to at least 3 months of age harboured adult hookworms in their intestines. Gross necropsy of more than 400 pups from 1999/2000 to 2004/2005 showed that the prevalence of hookworm infection varied significantly between years and was higher from mid-January to the end of February when the majority of pups were between 3 and 9 weeks old. The average burden of adult parasites per pup was not influenced by the host's sex and body condition or by year. This study also provided evidence for transmission occurring by the transmammary route in NZSLs.