Giardia infection in a group of experimental dogs

Twelve experimental dogs were monitored for Giardia infection over a 17 month period by both duodenal aspirate and zinc sulphate flotation of faeces. Each animal was found to be Giardia-pos-itive at least twice during this time despite treatment of positive animals. Giardia was frequently identified by both faecal examination and aspirate, but in some cases only one technique proved positive. The results indicated that faecal examinations are as effective as duodenal aspirates in the diagnosis of infection. At the end of the 17 month period six dogs were treated with corticosteroid: three of these treated dogs and one of six untreated animals became positive for Giardia.