WA Livestock Disease Outlook - for producers

Recent significant cases submitted to the Animal Health Laboratories

Case data from early December 2014 - mid-January 2015

Bovine anaemia due to Theileria orientalis group (BATOG)

  • A case of sudden collapse and death was investigated in a four-year-old cow in the lower Great Southern.
  • This followed five deaths in Shorthorn cows on this property over a six-month period.
  • The four-year-old cow became stressed after yarding, collapsed and died three hours later.
  • Ticks were noticed attached to soft areas of skin, especially around the udder, and they were identified as Haemaphysalis longicornis, commonly known as the bush tick.
  • Laboratory testing showed major damage in the liver.
  • Blood and bone marrow smears tested positive to Theileria orientalis var. ikeda, which was consistent with a diagnosis of bovine anaemia due to Theileria orientalis group (BATOG).
  • Read more on BATOG.

Selenium deficiency in mixed-age Friesian cows

  • A total of 35 mixed-age Friesian cows from three mobs totalling 90 cows on a property in the South-West were found to be non-pregnant.
  • There was no evidence of abortion and no cows were showing any signs of oestrus.
  • Blood samples from 23 of the non-pregnant animals tested negative for Brucella abortus, Leptospira spp., Neospora caninum and pestivirus.
  • Cobalt and copper levels were within normal ranges but there were very low activities of glutathione peroxidase in each sample tested, indicating selenium deficiency.
  • Selenium deficiency in cattle and sheep can lead to ill-thrift and low conception rates.

Salmonellosis in Merino ewes

  • Cases of sudden death and diarrhoea were investigated in Merino ewes in the central Wheatbelt.
  • 15 ewes died and 20 were clinically affected with diarrhoea in a flock of 300.
  • Diarrhoea and dysentery were seen in the clinically affected ewes with some showing tremors and weakness.
  • The flock was grazing canola stubble.
  • Post-mortem revealed a high sand content and bloody digesta in the small intestines. Eating sand can cause abrasions in the digestive tract, allowing bacteria to take hold.
  • Swabs were taken from the gastrointestinal tract and they all returned positive for Salmonella spp.
  • In a typical outbreak of salmonellosis, some sheep will be found dead and others acutely ill.
  • Read more on salmonellosis in sheep.

Lupinosis and liver damage in sheep

  • Neurological signs of an unsteady gait, tremors, collapse and then death were seen in five-month-old Merinos in the central Wheatbelt.
  • 50 sheep were affected and 20 were found dead out of a mob of 300. Some of the affected animals recovered with a short rest.
  • Two sheep showing clinical signs underwent post-mortem and subsequent laboratory examination led to a diagnosis of liver damage and lupinosis. Lupinosis most often occurs in summer and autumn.
  • Read more on lupinosis in sheep.

In late summer, be on the lookout for...

Lead poisoning

  • Many lead poisoning cases occur when hungry stock seek alternative feed sources.
  • Younger stock are more susceptible given their natural curiosity and relative size.
  • Affected stock are often found dead but may show muscle tremors and weakness, staggering and breathlessness.
  • Read more on preventing lead poisoning in livestock.

Vitamin E deficiency/nutritional myopathy in weaner sheep

  • This condition is most common in growing sheep after a prolonged period without access to green feed.
  • Clinical signs include lameness, ill-thrift and sudden death. The disease is often exacerbated by driving mobs and heavy worm burdens.
  • Read more on vitamin E deficiency.

Bovine anaemia due to Theileria orientalis group (BATOG)

  • Clinical signs: anaemia, listlessness, depression, jaundice, abortion, anorexia, weakness, collapse and sudden death.
  • Ticks are often seen on affected animals.
  • Early cases have been seen in January but case numbers may increase as calving progresses in the next few months.
  • Read more on BATOG.

Slender iceplant poisoning

  • This prostrate succulent is common in the eastern Wheatbelt.
  • Signs may include muscle weakness, sheep unable to stand, sternal recumbency, clear nasal discharge and occasionally bloat with decreased ruminal movement.
  • Read more on slender iceplant.

Farm biosecurity

Effective farm biosecurity helps reduce the likelihood of introducing disease onto your property. Following a simple biosecurity checklist which includes isolation and quarantine protocols when you introduce new animals to the farm could mean the difference between containing a disease to the isolated animal group or facing disease spread throughout the entire farm enterprise.

Help protect your farm’s biosecurity and productivity. Read more about a farm biosecurity checklist for sheep producers.

Previous issues

Previous issues of WALDO - for producers are available on the DAFWA website on the newsletter archive page.

Feedback

To provide feedback, email Dr Bruce Twentyman on bruce.twentyman@agric.wa.gov.au