Recent livestock disease cases in WA
Hendra virus exclusion in a horse showing neurological signs in the Pilbara
- An eight-year-old horse initially showed unusual behaviour (running away) and later, head pressing, ataxia, lethargy, recumbency. On examination the animal was tachycardic.
- No other horses on the property were affected.
- Key samples: Blood testing on EDTA, clotted and lithium heparin samples indicated hepatobiliary damage. Creatinine kinase was elevated, which could be attributed to the ataxia and recumbency.
- Reportable rule-out: Given the clinical signs, Hendra virus and equine encephalomyelitis (Eastern, Western and Venezuelan), equine herpesvirus and Murray Valley encephalitis and Ross River virus were tested for at DPIRD Diagnostic Laboratories (DDLS) and Australian Animal Health Laboratory (AAHL). Testing concluded none of these diseases were present.
- The hepatopathy and grazing history in this horse were consistent with pyrrolizidine alkaloid (PA) toxicity (Kimberley walkabout disease).
- Grazing Crotalaria spp. is a well-known cause of PA toxicity in livestock. This plant is known to occur in the Pilbara (see map of recorded sites of Crotalaria in WA on the Florabase webpage).
African and classical swine fever ruled out in pig at abattoir
- African swine fever (ASF) and classical swine fever (CSF) are highly contagious, unrelated viral diseases which affect pigs. They both can cause high mortalities and are exotic to Australia.
- In the severe form, signs include fever, loss of appetite, skin reddening, blue extremities, coughing, laboured breathing, diarrhoea, abortions and sudden death. The presentation may be milder and changes to the kidneys and tonsils may be observed at an abattoir.
- A grower pig presented for slaughter was found to have bilateral renal petechiation and samples were submitted to DDLS for investigation.
- In this case, ASF and CSF tests were negative. Porcine circovirus associated disease (porcine dermatitis and nephropathy syndrome) was identified as the cause of the renal pathology, which can also produce purple skin lesions and vascular organ lesions, particularly affecting the kidneys. Recent findings suggest a novel circovirus, PCV3, is associated with PDNS (https://www.ncbi.nlm.nih.gov/m/pubmed/27795441/).
- ASF and CSF could enter WA pig populations by feeding illegally imported pig meat or meat products to pigs (swill feeding). Contact with infected pigs or fomites could rapidly spread the disease causing high losses.
- For signs consistent with ASF or CSF, contact the Emergency Animal Disease hotline on 1800 675 888.
- Read more on Classical swine fever and African swine fever.
In summer, watch for these livestock diseases:
|Disease||Typical history and signs||Key samples|
|Bovine anaemia due to Theileria orientalis group (BATOG)|| || |
|Kikuyu poisoning|| || |
|Water quality issues|| || |
Water samples can be tested for salinity and blue-green algae at DDLS
Reminder to be aware of melioidosis potential after heavy rain
With the recent rainfall across the state, DPIRD encourages vets to monitor for potential cases of melioidosis in animals. Melioidosis is mainly associated with tropical and subtropical regions, but it has occasionally been detected in temperate regions. Recent heavy rainfall may increase the risk of melioidosis, and cases have occurred previously in the Chittering and Toodyay shires. If you see signs of disease in animals that could be melioidosis, contact your DPIRD Field Veterinary Officer for assistance. While the risk of transmission of melioidosis from animals to humans is low, personal protective equipment should be worn to prevent droplet or respiratory infection when dealing with suspect cases.
For more information about melioidosis, including species-specific clinical signs, see the melioidosis webpage.