Entry to and exit from contaminated premises - by animal health personnel, workers, owners, wildlife, insects, domestic animals and rodents-present a risk of disease spread which demands constant attention. The least expensive means of controlling and eliminating the risk of introducing virus and bacteria involves maintaining constant biosecurity programmes. These documented biosecurity measures and procedures must never be compromised by anyone including the owners of premises. When time and the monetary investment involved in large and small animal production operations are considered, biosecurity precautions are a small investment cost in keeping the herd or flock free of infections disease microorganisms.