WA Livestock Disease Outlook - for producers

Recent livestock diseases

Lupinosis detected in Wheatbelt sheep

  • Six of 1500 merino wether lambs died on a property in December, with a further 800 animals affected. The affected sheep appeared lethargic and had been losing condition. 
  • Sheep were recently purchased from a Wheatbelt property and had been grazing a lupin stubble for the past 6-8 weeks.
  • Two lambs showed neurological signs including facial twitching and apparent blindness. The lambs were lying down and had difficulty rising.
  • The producer contacted their private vet to conduct a disease investigation and received a subsidy through the Significant Disease Investigation Program.
  • Always contact a vet if you see unusual signs in livestock. Producers can access a variety of subsidies for disease investigations in livestock. These subsidies are designed to support Western Australia’s market access and food safety. For more information speak to your vet or visit the surveillance incentives webpage.
  • The private vet examined the sheep, conducted a post-mortem and submitted samples to DPIRD for testing.
  • Testing of the liver confirmed a diagnosis of lupinosis, which causes severe liver damage. Loss of liver function leads to a condition of impaired brain function known as hepatic encephalopathy.
  • Blood results showed that both animals also had a vitamin E deficiency.
  • Testing also ruled out lead toxicity, which could also cause blindness and lethargy in sheep (and cows), and is a risk to human food safety and access to export markets if found in food-producing animals.
  • Lupinosis is a liver disease caused by the consumption of lupin stubble colonised by the fungus Diaporthe toxica (previously called Phomopsis leptostromiformis). It can be expressed in either an acute form or a chronic liver dysfunction syndrome. The acute form is most likely to occur after summer rains where the lupin stalk becomes softened and more palatable to livestock. All livestock are susceptible to lupinosis but sheep are the most susceptible. Weaners are most commonly affected because they tend to eat the stem of the lupin. 
  • Vitamin E deficiency is widespread in weaner sheep flocks in WA over the long, dry summer-autumn period when green feed is scarce. Signs of vitamin E deficiency in sheep include weaner illthrift, reduced wool production, reduced ewe fertility, reduced immune response and damage to the muscles resulting in lameness and weakness.
  • Read more about lupinosis in sheep and vitamin E deficiency in sheep.

Cow with skin growths tests negative for exotic disease

  • A private vet examined a 2-year-old cow with skin growths covering the face and neck.
  • The vet suspected warts due to bovine papillomavirus but wanted to rule out the exotic disease lumpy skin disease, which can cause similar signs. Samples were submitted to DPIRD and the submission was exempt from laboratory fees because a reportable disease was excluded.
  • One cow from a group of 30 was affected (Figure 1).
  • Lab testing confirmed cutaneous papillomas (warts) due to bovine papillomavirus and ruled out the exotic reportable disease lumpy skin disease. 
  • Warts in cattle can be caused by bovine papillomavirus. They commonly occur on the skin of young animals between 6 and 24 months of age. Usually the warts go away spontaneously as the cattle develop immunity to the virus but may persist for up to 12 months in some animals, especially animals that are immunocompromised.
  • Bovine papillomavirus can be transmitted between cattle directly, or via contaminated surfaces such as water troughs and fence posts.
  • The negative result for lumpy skin disease in this case helps to support WA’s market access by demonstrating freedom from the disease.
  • Lumpy skin disease is a highly infectious disease of cattle. It is mostly transmitted by biting insects.
  • Lumpy skin disease is exotic to Australia. The international distribution of lumpy skin disease is increasing in range, and it would have a significant impact on cattle productivity if it entered Australia. Disease signs include lumps on the skin, fever, salivation and nasal discharge. If you see any unusual signs in livestock, you should always contact a vet.
  • Read more about lumpy skin disease in Emergency Animal Disease Bulletin No. 121
cow with warts
Figure 1. Cow with skin growths on the head