WA Livestock Disease Outlook - April 2013 - Agric.wa.gov.au

WA Livestock Disease Outlook
Producer edition │April 2013
The monthly WA Livestock Disease Outlook (WALDO) provides producers with a brief overview of
recent significant livestock disease cases investigated by the Animal Health Laboratories (AHL).
Past issues of WALDO are available here.
Recent significant cases submitted to AHL
Case data from late February to April 2013
Annual ryegrass toxicity (ARGT) associated with hay
Several cases of ARGT associated with hay were investigated in horses and sheep.
In one case:
- horses developed muscle twitching and uncoordinated movements
- their faeces tested positive for the toxic bacteria that causes ARGT and the hay they were being
fed tested as high risk for causing ARGT
- note: the property that produced the hay is located in the Great Southern in an area not usually
regarded as being at risk of ARGT.
Before buying hay, producers should ask their supplier if the hay has been tested for ARGT and
found to be low risk.
Read more here or search ‘ARGT’ at agric.wa.gov.au.
Ketosis in cattle
AHL investigated five cases of ketosis in beef and dairy cows across the agricultural regions.
In one case:
- 6 of 120 cows in late pregnancy or early lactation became uncoordinated, were unable to rise
and some died
- the cows became ill within 24 hours of being moved to a barley stubble and regrowth paddock
- post-mortem and lab testing results supported a diagnosis of ketosis.
Ketosis commonly occurs at this time of year when cows are in late pregnancy or early lactation and
their glucose demands are high.
Salmonellosis in sheep and cattle
AHL investigated several cases of salmonellosis in sheep and cattle across the agricultural regions.
In one case, mixed-age Merino ewes purchased two weeks earlier developed scours and were
unable to rise, with laboratory testing suggesting salmonellosis was the cause.
In another, 4 beef calves from a group of 35 died suddenly and salmonella bacteria were grown
from the faeces.
Salmonellosis in autumn is often associated with hand feeding and concentration of stock in
feedlots or around watering points.
Read more here or search ‘salmonellosis’ at agric.wa.gov.au
Trace element toxicity in sheep and cattle
A case of copper toxicity caused cattle deaths:
- cows died 24 hours after receiving an injection containing vitamin B12, selenium and copper
- testing showed toxic levels of copper in the kidney and elevated levels in the blood and liver
- the cows probably had adequate or high copper levels before the supplement was given
- producers should consider testing to determine if copper deficiency is present before
supplementing with copper. For more information contact your veterinarian.
Selenium toxicity caused sheep deaths:
- 3–4-year-old sheep died after grazing a paddock that recently had selenium chips applied
- laboratory testing confirmed liver selenium levels were in the toxic range.
These cases highlight the importance of choosing appropriate products for trace element
supplementation and following label directions.

In late autumn be on the lookout for...
Disease
Pregnancy toxaemia in
ewes
Hypocalcaemia
in ewes
Salmonellosis
Calf scours
Usually affects late-pregnant ewes.
Typical history and signs
Affected ewes typically separate from the flock and appear blind.
Over a few days they lie down, develop muscle twitching and die.
Read more here or search ‘pregnancy toxaemia’ at agric.wa.gov.au
Usually affects ewes in late pregnancy or early lactation, often after stressful
events.
May be seen in sheep grazing cereal regrowth or high oxalate pastures.
Typically causes sudden onset uncoordinated gait with muscle tremors and
death within 24 hours.
Read more here or search ‘hypocalcaemia’ at agric.wa.gov.au
Most common in intensively farmed livestock.
Causes profuse diarrhoea. Sheep may be found dead and pregnant ewes may
abort.
Stress and high stocking density are common precursors to an outbreak.
Read more here or search ‘salmonellosis’ at agric.wa.gov.au
Typically affects young calves in late autumn and early winter.
Commonly caused by viruses (e.g. rotavirus), protozoa (e.g. cryptosporidium)
or bacteria (e.g. salmonella or E. coli).
Calves can quickly dehydrate so it is important to provide supportive care.
Read more here or search ‘calf scours’ at agric.wa.gov.au
For more information about these diseases, contact your private veterinarian or local Department of
Agriculture and Food (DAFWA) veterinary officer.
If you notice any unusual signs of disease in your stock or have unexpected stock deaths, contact your
private veterinarian, local DAFWA veterinary officer or phone the Emergency Animal Disease hotline on
1800 675 888.
Would you recognise foot-and-mouth disease in your cattle?
Australia has not had an outbreak of foot-and-mouth disease (FMD) for over 100 years, but it is
important we do not become complacent. Farmers and all other people who work with livestock need to
know what FMD looks like and report any suspect animals immediately.
Signs of FMD in cattle include:
severe depression, lack of appetite
a sudden drop in milk yield
sudden death in young calves
reluctance to move progressing to severe lameness
copious drooling and lip smacking
blisters may be visible in the mouth and on the lips and around the top of the foot but are often not
obvious until they rupture.
If you suspect FMD, immediately contact your veterinarian, local DAFWA veterinary officer or phone
the Emergency Animal Disease hotline on 1800 675 888. The faster the disease is detected, the faster
it can be eradicated and the lower the social and economic impact of the disease.
For more information on FMD click here or search ‘FMD’ at agric.wa.gov.au
DAFWA welcomes your feedback on WALDO. Please provide comments to katie.webb@agric.wa.gov.au.
Disclaimer: The Chief Executive Officer of the Department of Agriculture and Food and the State of Western
Australia accept no responsibility whatsoever by reason of negligence or otherwise arising from the use or
release of this information or any part of it.