WA Livestock Disease Outlook - for producers

Joint approach to prevent African swine fever

DPIRD and WA pork industry representatives at the African swine fever preparedness workshop in April 2019

DPIRD and the WA Pork Producers Association have been working together to ensure WA commercial pig producers are well informed about mitigating the risks of African swine fever as well as increasing preparedness for a potential outbreak. Pictured above are some of the industry attendees and DPIRD facilitators of the recent African swine fever workshop.

Read more on the threat of African swine fever to WA and Australia in this update from the WA Chief Veterinary Officer Michelle Rodan.

Recent livestock disease cases in WA

Mouth lesions in feedlot cattle test negative for foot-and-mouth disease (FMD)

Figure 1: Cow with nasal erosion

Figure 2: The tongue of the same cow, showing erosions

• Western Australia’s access to livestock and livestock product export markets, worth about $2 billion annually, relies on Australia being free of FMD.
• Signs of FMD may include:
  • blisters in the mouth, nostrils, teats or feet
  • drooling
  • lameness 
  • depression
  • loss of appetite
  • drop in milk yield in dairy cows
  • sudden death in young animals and abortion in pigs.
• Always report signs that could be FMD to a DPIRD vet or the Emergency Animal Disease hotline on 1800 675 888. Early detection = faster eradication = less impact on your business and community.
• In April, in a group of 300 18-24 month-old feedlot cattle, eight died and three more were affected over a one-week period.
• Disease signs included depression, runny nose, slobbering and open mouth breathing. Some animals had nervous signs including an uncoordinated gait and head pressing. Staff at the feedlot noticed one animal had healing erosions on the tongue and nose (see Figures 1 and 2) and reported this to the local DPIRD field vet, demonstrating the benefits of previous training in emergency animal disease signs and willingness to report a suspect reportable disease.
• The DPIRD field vet conducted an on-farm investigation and post-mortem examination, and submitted samples to the DPIRD laboratory. The vet suspected the deaths were due to a bacterial infection with Histophilus somni, polioencephalomalacia, bacterial pneumonia or acidosis. 
• While FMD was considered unlikely to be the cause of the disease in this group of cattle, the presence of oral and nasal erosions in one cow warranted exclusion testing. All samples tested negative for FMD.
• Testing at the DPIRD laboratory showed the illness and deaths were caused by an infection with the bacteria Histophilus somni. This diagnosis allowed the producer to instigate a prompt treatment plan with their private vet to prevent further losses. All laboratory fees were paid by DPIRD.
• The oral lesions were suspected to be due to grass seeds in rough feed.  
• The most likely way FMD could occur in Australia is through the illegal feeding of meat products to pigs. Pigs infected with FMD produce great volumes of virus, which can spread to neighbouring properties via wind or by people or equipment movement, and can then infect other susceptible animals including sheep, cattle and other pigs.
• To find out more about FMD, see our FMD webpage or watch our FMD video. For information on safe feeds for pigs, see our pig feed webpage.
• If you suspect that anyone is supplying meat products for pig feed or feeding pigs with meat products, protect your business and your industry – contact 1800 675 888 or your nearest DPIRD vet.

An unusual presentation of pulpy kidney in Merino ewes in the Midwest

• In a flock of seven-year-old Merino ewes, four died and two were unwell from a flock of 340.
• Affected ewes were found down in the paddock with tremors, difficulty breathing and diarrhoea. All affected ewes were twin-pregnant. The flock was grazing a cereal rye paddock supplemented with lupins, and calcium licks were available.
• The producer contacted a DPIRD field vet, who visited the property and conducted a post-mortem examination on one ewe. This ewe had a full rumen, a pale, swollen liver and was in body condition score of 3. The DPIRD field vet suspected milk fever (hypocalcaemia) but collected a full sample set to enable an accurate diagnosis.
• Testing at the DPIRD laboratory showed that calcium levels were normal, and that milk fever was therefore not the cause of disease. Pulpy kidney (enterotoxaemia) was diagnosed.
• Pulpy kidney is a disease of sheep, goats and cattle. It occurs in sheep when a bacterium that normally inhabits the animal’s intestines without causing problems begins to multiply and produce a toxin that poisons the animal. Pulpy kidney most commonly occurs in rapidly growing lambs on lush pasture or grain. In older sheep, pulpy kidney is most likely to occur just after they are moved to good feed from poorer feed. However, the disease can occur at any time.
• This diagnosis was reported to the producer, who was able to prevent further losses in the flock. Read more on our webpage about pulpy kidney.
• As the affected ewes showed tremors, samples were also collected to exclude transmissible spongiform encephalopathies (TSEs). These samples tested negative for TSEs.
• The National TSE Surveillance Program conducts surveillance for bovine spongiform encephalopathy (BSE or mad cow disease) in cattle and scrapie in sheep. Producers with cattle or sheep with neurological signs or sheep with persistent itchiness not caused by lice should contact their DPIRD field vet to discuss the inclusion of the animal in the program. Producers and vets who have suitable cattle and sheep autopsied under the program may claim a rebate.
• The program supports our continued access to markets by proving we are free of TSEs.

In autumn, watch for these livestock diseases: