Livestock and pets are prone to many different intestinal parasites. Some of these can cause ill thrift, scouring, anaemia or even death.

Nematodes (such as the deadly barbers pole worm)
Common nematodes found in livestock include the roundworms, black scour and barbers pole worm. These hook into the wall of the stomach or small intestine with specialised mouth parts, make a small cut and then proceed to feed on the blood of the host animal. Each cut creates a small scar, which cannot absorb nutrients. The more scars an animal has, the more it needs to eat to get the same amount of nutrients from the feed. If nematode infestations continue untreated, the animal becomes anaemic and will eventually die. 

Barbers pole worm burdens can build up quickly to deadly levels in sheep and goats. The worms become active after the first spring rains, when the weather starts to warm up. Within 21 days after ingestion, the parasite begins laying 5,000-10,000 eggs per day.  

Barbers pole worm accounts for more livestock deaths in sheep and goats than any other parasite in Australia.