WA Livestock Disease Outlook - for producers

Exotic animal disease alerts

Lumpy skin disease

In March 2022, lumpy skin disease (LSD) was detected in Sumatra, Indonesia. The disease continues to expand in the East Asia and Pacific region, increasing the risk to Australia. For more information on LSD, including disease signs and spread, see our LSD webpage.

Foot-and-mouth disease

In May 2022, foot-and-mouth disease (FMD) was detected in Java and Sumatra, Indonesia. Until this outbreak, Indonesia had been FMD free since 1986. FMD is a highly infectious viral disease that affects cloven-hoofed animals including sheep, cattle, pigs, goats, buffalo, camels, alpaca, llama and deer. Australia is free of FMD, which increases our access to livestock and livestock product export markets. Anyone keeping or working with cattle, sheep, goats or pigs should be aware of the signs of FMD: blisters on the mouth and drooling or limping animals. The most likely way FMD could enter Australia is by the illegal importation of meat and dairy products, which can carry the virus. For more information, see our FMD webpage.

Japanese encephalitis virus

Japanese encephalitis (JE) was detected in piggeries in Victoria, New South Wales, Queensland and South Australia in early 2022. The disease has not been detected in Western Australia. JE is an acute mosquito-borne viral disease that can cause reproductive losses and encephalitis in susceptible species. Pigs and horses are the most commonly affected animal species, but JE virus is zoonotic and can pose a serious risk to human health. For more detail on JE in animals, see our JE webpage.

LSD, FMD and JE are all reportable diseases. If livestock show any unusual disease signs, call your local DPIRD veterinarian or the Emergency Animal Disease (EAD) Watch Hotline on 1800 675 888. The earlier disease is detected, the faster we can respond.

Recent livestock disease investigations

Foot-and-mouth disease ruled out in steers in the South-West

• Six out of 30 steers were unloaded at a feedlot with salivation and mouth ulcers. Another 20 steers arrived during the day from the same property of origin and 10 were salivating. On closer inspection, half of the steers (25/50) had mouth ulcers.
• The steers were bought from a saleyard the day before, and there were no unusual signs of disease when the steers were loaded onto the truck.
• A private vet observed the clinical signs and called the EAD hotline to notify the suspicion of the exotic animal disease, foot-and-mouth disease (FMD). A DPIRD vet attended to help with the investigation and found affected steers had moderate to high temperatures and mouth ulcers but no other signs of disease. Another DPIRD vet went to the property of origin and found mouth ulcers in seven of the steers examined (Figure 1).
• Samples were collected from both properties and submitted for laboratory testing.
• Testing was positive for bovine papular stomatitis virus, which is a parapox virus. Testing for the reportable diseases FMD, vesicular stomatitis, bovine viral diarrhoea Type II and malignant catarrhal fever returned negative results.
• Bovine papular stomatitis is a mild viral disease usually affecting cattle less than two years old that typically resolves with no need for treatment. Infection with this virus can result in ulcers or sores around the mouth and elsewhere on the skin, but affected cattle often show no signs of disease. People in close contact with infected animals may develop skin sores and pustules on their hands, arms or legs.
• Signs similar to foot-and-mouth disease, such as mouth ulcers and drooling, should always be reported to a DPIRD vet or the Emergency Animal Disease hotline on 1800 675 888. Early detection = faster eradication.

Figure 1: Mouth ulcers in a steer

Jaundice and swollen faces in Merino ewes in the Midwest.

• In a flock of 550 mixed age Merino ewes, six had to be euthanised due to severe signs of jaundice, dehydration, facial swelling and scabbed oral sores. More than 30 other ewes were mildly affected with swollen faces, jaundice and scabby muzzles (Figure 2).
• The producer contacted their local DPIRD vet to investigate the large number of ewes affected and unusual signs of disease in their flock.
• The flock had been moved onto a new pasture 10 days ago which contained the weed caltrop (Figure 3). Caltrop is widespread throughout Western Australia and can be identified by its star-shaped spiny burrs and small yellow flowers. Seeds remain dormant in the soil and germinate following summer rains.
• On post-mortem of one ewe, there was diffuse yellowing of the carcass, signs of pneumonia and a swollen, yellow liver (Figure 4). Blood samples were collected from three live sheep as well as faeces, fresh and fixed samples from one euthanised animal. The samples were submitted with a working diagnosis of unusually severe caltrop toxicity and secondary photosensitisation.
• Testing identified liver and kidney damage, consistent with caltrop toxicity, which can lead to photosensitisation.
• Additional testing excluded the exotic disease bluetongue virus. In the acute stage, sheep with bluetongue may present with high temperatures, salivation, nasal discharge causing crusting around the nostrils, swollen lips and tongue which may extend to include the ears.
• Photosensitisation can result from consuming plants containing compounds which are activated by exposure to light, or it can occur secondarily from liver damage, as in cases of caltrop toxicity.
• The affected group was moved into a new paddock with no caltrop and plenty of access to shade. Livestock affected by photosensitisation should be protected from sunlight as it activates inflammatory compounds in the skin, resulting in damage such as the scabby muzzles. In the recovery period, limit access to grain and high-protein feed.
• Results from this investigation help to provide evidence that WA is free from important exotic diseases and supports our access to markets. Read more on bluetongue virus.

Figure 2: Facial swelling and mild muzzle erosions

Figure 3: Caltrop in flower

Figure 4: Diffuse icterus (jaundice) and bronchopneumonia

Diseases to watch out for in winter

Arthritis in lambs

• Erysipelas is the most common 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 bacteria to enter and arthritis to develop.
• 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 of your ewes with your vet.
• Investigate the cause of lameness, particularly when more than one animal is affected, as a range of endemic diseases 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 rule out exotic diseases including FMD and bluetongue virus.
• Read more on arthritis in sheep.

Copper deficiency in sheep and cattle

• Copper is an essential trace element for animals needed for body, bone and wool growth, pigmentation, healthy nerve fibres and white blood cell function. Rapid pasture growth after good winter rains reduces the concentration of copper in pasture.
• Seasonal variation in the availability of copper from pastures makes sheep and cattle most at risk of a deficiency during late winter and spring.
• Clinical signs of copper deficiency in cattle
  • loss of pigment from coloured hair especially around the eyes
  • falling disease – sudden heart failure causing sudden death
  • lameness.
• Clinical signs of copper deficiency in sheep and goats:
  • swayback or uncoordinated legs (enzootic ataxia) of lambs and kids
  • loss of pigmentation in black-woolled sheep and steely or harsh wool
  • increased incidence in fractures of the long bones and rib bones in lambs.
• Read more on copper deficiency.

Bovine anaemia Theileria orientalis group (BATOG)

• BATOG occurs in cattle in southern WA where the bush tick, Haemaphysalis longicornis, is found. Infected ticks spread the blood parasite T. orientalis.
• Signs of BATOG include anaemia, abortion, pale or yellow mucous membranes, laboured breathing, weakness, collapse.
• The disease may cause deaths in young stock. Healthy young stock that become infected may develop immunity but continue to carry the parasite.
• Your vet can assist with supportive care for BATOG.
• Producers with cattle with anaemia, jaundice and abortion can receive free testing under the BATOG surveillance program – contact your private vet or DPIRD field vet for information.
• Read more on the BATOG webpage.

Exotic disease in the spotlight: Lumpy skin disease

• Lumpy skin disease, caused by a virus in the pox family, 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.
• LSD first occurred in Africa. From the late 1980s it was detected in parts of the Middle East, from 2012 in Europe, and from 2019 in mainland South-East Asia, gradually moving east. In March 2022, it was detected in Singapore and Indonesia. LSD has never been recorded in Australia, but its presence in near neighbours has increased the likelihood of introduction.
• Bos taurus (southern) cattle are more susceptible to the disease than Bos indicus (northern) breeds, with some dairy breeds (Jersey, Guernsey, Friesian and Ayrshire) particularly susceptible. Asian water buffalo (Bubalis bubalis) can be infected, but clinical disease may be milder. 
• Disease signs include multiple lumps over the body which range from 2-5cm in size, fever, salivation and nasal discharge (Figure 5). There is a rapid loss of condition, lumps may persist for 4-6 weeks, and can take up to six months to fully resolve.

Lumpy skin disease is a reportable disease in Australia. If you notice signs that look like Lumpy skin disease, or any other unusual disease signs, contact your DPIRD vet or the emergency animal disease hotline on 1800 675 888. More information can be found on our lumpy skin disease webpage or from the Department of Agriculture, Water and the Environment.

Figure 5: Native Lao cattle with Lumpy Skin disease (Source: unknown)

Neurologic signs in cattle or sheep? Remember Bucks for Brains!