WA Livestock Disease Outlook - for vets

Gastrointestinal (GIT) worms in cattle

• Mild summer weather and some rain may have allowed survival of infective larval stages on pasture in the southwest.
• Recent cases of cattle showing signs including diarrhoea, lethargy and poor body condition have been submitted to DPIRD. Testing has found significant worm burdens and GIT damage despite drenching. This can lead to reduced immunity and poorer outcomes when cattle are affected by other conditions.
• In winter rainfall areas, the brown stomach worm (Ostertagia ostertagi) is a major parasite of cattle.
• Ensure drenches are effective against parasites in your region and administered correctly. See the DPIRD drenching beef cattle webpage for more information.

Ante-mortem:

• Faeces: 4g in cattle for worm egg count.

Post-mortem:

• Alimentary sections: fresh and fixed
• GI contents (abomasal contents, SI contents)
• Faeces

Pregnancy toxaemia in ewes

• Consider pregnancy toxaemia if late pregnant/early lactating ewes present with depression, anorexia, weakness, recumbency, neurologic signs, and death. Signs may be worse following stress. Affected ewes may separate from the mob.
• Ewes carrying multiple lambs are at higher risk and if identified early at scanning can be separated and fed carefully.
• Pregnancy toxaemia can be avoided if producers provide adequate nutrition to the ewes and minimise stress (e.g. avoid herding and yarding of ewes in late pregnancy and early lactation).
• Differential diagnoses: Scrapie (exotic), cerebral abscess, acidosis, enterotoxaemia, hypocalcaemia, nutritional myopathy in primiparous ewes and meningitis.
• Early diagnosis and treatment with glucose and supplementary feeding of good quality hay and oats can halt deterioration.
• DPIRD’s pregnancy toxaemia webpage has information on prevention and treatment.

Ante-mortem:

• 10mL blood in lithium heparin tube

Post-mortem:

• 2mL vitreous humour in plain tube (post-mortem) in addition to base tissue sample set.
• Adult sheep showing neurological signs should be tested for reportable diseases such as scrapie. Speak to your DPIRD vet about subsidised investigations.

Calf diarrhoea/scours

• Affects young calves in autumn and early winter. Newborn calves that received a good supply of colostrum from their dams will be better protected.
• Signs include depressed appearance, diarrhoea, dehydration, recumbency and death.
• Calf scours may be caused by single or multiple organisms. Some common organisms include coronavirus, rotavirus, E. coli, Salmonella and Cryptosporidium. Cows can be vaccinated against a number of these prior to calving.
• DPIRD’s calf scours webpage contains a number of strategies to prevent and treat an outbreak.

Ante-mortem:

10mL faecal sample (chilled) from 5 affected animals if possible