Knotty Gut/Pimply Gut

March 2016 [email protected] Knotty Gut/Pimply Gut

Knotty gut and pimply gut are caused by nodule worm, Oesophagostomum columbianum. Lesions seen at the abattoir vary from small gritty lesions in the small intestines to large abscess like lesions in the large intestine. If infection is severe nodules may also be found in other organs, such as the lung, liver and kidneys.

ECONOMIC CONSEQUENCES On Farm At the Abattoir

 Reduced growth rate/weight  Condemnation of loss – can cause significant runners (intestines). production losses.  Deaths

WHAT CAUSES KNOTTY GUT/PIMPLY GUT? Nodule worm is relatively uncommon in South Australia because the parasite prefers areas of summer rainfall as found in New South Wales and Queensland. Most cases detected in SA are found in sheep sourced from interstate however nodule worm can cause infection on SA properties if infected sheep are introduced and weather conditions are favourable (i.e. an unusually wet summer).

WHAT MIGHT BE SEEN ON FARM? Nodule worm causes disease both in larval and adult form. Clinical signs can include:  Diarrhoea – can contain mucous and blood

 Anorexia, weight loss

 Low protein and anaemia (pale gums); and

 Death. The adult parasite causes disease due to its feeding activities which damages the colon causing ulcers and bleeding. Nodule worm larvae cause disease by forming nodules in the gut lining. Larvae may emerge from these nodules causing bleeding or remain encased until they are destroyed by the sheep’s immune system. The damage to the gut these nodules cause can be severe and interfere with normal gut motility. Considerable pain can result from peritonitis and adhesions between loops of gut due to the damage done by these nodules. Sheep may stand with a hunched back and have a stiff gait.

TREATMENT  Nodule worm is easily treated with broad spectrum drenches however once sheep have developed nodules in the walls of the intestine they do not recover fully. PREVENTION 1. Quarantine Drench - prevent bringing any resistant worms onto your property (this is information not specific to nodule worm but to all parasites) by administering a quarantine drench to all purchased sheep as they come onto the property:

 Dose with a combination of four unrelated actives: 1. Benzimidazole (BZ, ‘white’) 2. Levamisole (LEV, ‘clear’) 3. Macrocyclic lactones (MLs, ‘-ectins’); and 4. Monepantel (Zolvix ®).

 Keep stock off pasture for three days (hold in yards or a small holding paddock) until all eggs present have passed from the gut. If a small holding paddock is used, spell this from sheep (and goats or alpacas) for three (summer) or six (winter) months.

 Release sheep onto the wormiest pastures available to ‘dilute’ any quarantine survivors.

2. Faecal Egg Counts - monitor worm burdens using faecal egg counts and drench strategically.

 An excellent source for detailed information on recommended times to drench and on making drenching decisions, based on faecal egg counts, can be found at http://www.wormboss.com.au/programs/sa.php This information is specific for state and area and, in the case of the Drench Decision Guide, your property. FOR FURTHER INFORMATION: contact the Enhanced Abattoir Surveillance Program manager Dr Elise Matthews, your local veterinarian, livestock consultant or PIRSA Animal Health Officer. FOR ANY SIGNS OF UNUSUAL OR SERIOUS DISEASE, PLEASE CALL THE ANIMAL DISEASE HOTLINE: 1800 675 888