WA Livestock Disease Outlook - for producers

Calling a vet to investigate disease protects our markets

The WA Livestock Disease Outlook provides information about recent livestock disease cases in Western Australia and diseases likely to occur in the next month. Calling a vet to investigate diseases when they occur provides surveillance evidence to our markets that we are free of reportable and trade-sensitive diseases.

Recent livestock disease cases in WA

Weakness and deaths in ewes during lambing in the Great Southern

  • A total of 23 mixed age lambing ewes in a mob of 300 died over the course of a week with those affected lethargic, lying down and panting, with death occurring within 12 hours. Once the affected ewes laid down, they did not respond to treatment with glucose and electrolytes.
  • During the previous month, the sheep had been transitioned from trail mix to barley and lupin lick feeders. They had been vaccinated for cheesy gland and clostridial diseases, drenched with a macrocyclic lactone within the last month and recent worm egg counts showed a low worm burden in the flock.
  • The vet conducted a post-mortem on two affected ewes in good body condition and at different stages of pregnancy.
  • The brain was submitted for lab testing, which showed one ewe had lesions in brain vessels. This ewe was also tested for the exotic disease, scrapie, with negative results. Because this case was a rule-out for scrapie, it was eligible for a subsidy, so the producer was not charged for the cost of lab testing and received a rebate. Read more about subsidies for vet investigations and for scrapie investigations.
  • Testing of intestinal contents resulted in a positive for enterotoxaemia (pulpy kidney). Despite the name, ‘pulpy kidney’, cases may present as sudden death with no kidney abnormalities visible on post-mortem.
    Dissecting the kidneys
    Figure 1: Normal kidney appearance. Not all cases of pulpy kidney will have visible ‘pulpy’ kidney lesions.
  • Follow-up investigation by the vet found that the annual vaccination for older ewes had lapsed. The younger ewes had been vaccinated against pulpy kidney during the previous year but the initial vaccination course had been incorrectly administered at two-week intervals instead of the recommended four weeks, which could explain losses in this age group.
  • Read more on enterotoxaemia (pulpy kidney) in sheep.

Sudden deaths and lethargy in cows in the South West at calving

  • A total of 13 late-pregnant and calving cows died suddenly and the producer noted another 57 were lethargic and lying down. A mob in the neighbouring paddock seemed unaffected.
  • The cows were grazing a paddock with standing hay, were up-to-date with vaccination and had been drenched in the past three months.
  • On post-mortem, one cow was in poor body condition and had pale mucous membranes, a thickened fourth stomach, enlarged lymph nodes in the abdomen and bright yellow fat.
  • Lab testing determined the cow had a severe, chronic inflammation of the intestines, inflamed fourth stomach and fatty liver. Blood results also showed liver disease and high BHB (beta-hydroxybutyrate) levels, resulting in a diagnosis of ketosis.
  • A very high worm count in the fourth stomach indicated a severe worm burden and pasture contamination had contributed to disease.
  • It was recommended that the affected animals receive further drenching and monitoring for worm egg counts as well as supplementary feeding. Information for drench management including resistance can be found on our drenching beef cattle webpage.

In early winter, watch for these livestock diseases:

Disease, typical history and signs

Grass tetany in cattle

  • Susceptible cattle are generally older, highly productive cows in their first four months of lactation, grazing grass pasture.
  • Signs may include twitching, convulsions, excitement, apparent aggression, stiff gait and sudden death.
  • Magnesium-deficient cattle normally present with signs similar to transmissible spongiform encephalopathies (TSE) and may be suitable for a testing subsidy. See the TSE webpage or contact your DPIRD vet for details.
  • Read more on grass tetany in beef cattle.

Arthritis in lambs

  • Erysipelothrix rhusiopathiae is the most common cause of bacterial arthritis in lambs in WA.
  • Lambs are most susceptible to infection soon after birth (via the umbilicus), at marking, mulesing and shearing. Any break or wetting and softening of the skin can allow the entry of bacteria and development of arthritis.
  • Prevention includes proper disinfection of equipment and avoiding wet, muddy conditions if mulesing, marking and shearing. If erysipelas arthritis is a problem in your flock, discuss vaccination with your vet. 
  • It is always advisable to investigate the cause of lameness, particularly when more than one animal is affected, as there is a range of endemic diseases that can cause lameness such as footrot, foot abscesses, laminitis from grain overload, scabby mouth extending to the lower legs, rickets, white muscle disease. It is also vital to consider the possibility of exotic diseases such as foot-and-mouth disease and bluetongue, as it would be crucial to detect these diseases early if they did occur.
  • Read more on arthritis in sheep.

Health issues caused by reduced feed/buying in feed