WA Livestock Disease Outlook - for producers - August September 2017

In early spring, watch out for these livestock diseases in WA:

Disease	Typical history and signs
Polioencephalomalacia (PEM) in sheep and cattle	PEM most often occurs in WA when there is a sudden change to feed composition. All ages and classes can be affected and it can involve up to 10% of the mob. Signs include muscle twitching, seizures, head pressing, blindness, paddling and head thrown back, death. Note: the signs of lead poisoning (reportable) can look similar. Thiamine deficiency is the most common cause of PEM in WA but there can be other causes. Animals treated in the early stages with thiamine may recover. Read more on our PEM webpage. Eligible disease investigations can be subsidised by the SDI program – contact your DPIRD field vet officer for information.
Worms in sheep and cattle Read more on sheep worm control Read more on beef cattle worm control	Signs of Barber’s pole worms include bottlejaw, fluid-filled abdomen and anaemia. Signs of other worm burdens include weakness, lethargy, production losses, weight loss, and diarrhoea. Worm burdens can cause significant damage to the intestines. Young sheep and cattle require good worm control to achieve their potential growth rate. High stocking rates favour the spread of worms. Lambs will require an effective drench at weaning and ideally be put onto a paddock with a low worm burden. Scour worms are expected to be prevalent this spring following recent seasonal conditions. Worm egg counts are a useful tool to measure drench effectiveness. See the sheep Drench Decision Guide on the Wormboss website or read more on the DPIRD website on drench resistance.

Disease

Typical history and signs

Polioencephalomalacia (PEM)
in sheep and cattle

PEM most often occurs in WA when there is a sudden change to feed composition.
All ages and classes can be affected and it can involve up to 10% of the mob.
Signs include muscle twitching, seizures, head pressing, blindness, paddling and head thrown back, death. Note: the signs of lead poisoning (reportable) can look similar.
Thiamine deficiency is the most common cause of PEM in WA but there can be other causes.
Animals treated in the early stages with thiamine may recover. Read more on our PEM webpage.
Eligible disease investigations can be subsidised by the SDI program – contact your DPIRD field vet officer for information.

Worms

in sheep and cattle
Read more on sheep worm control
Read more on beef cattle worm control

Signs of Barber’s pole worms include bottlejaw, fluid-filled abdomen and anaemia.
Signs of other worm burdens include weakness, lethargy, production losses, weight loss, and diarrhoea. Worm burdens can cause significant damage to the intestines.
Young sheep and cattle require good worm control to achieve their potential growth rate.
High stocking rates favour the spread of worms. Lambs will require an effective drench at weaning and ideally be put onto a paddock with a low worm burden.
Scour worms are expected to be prevalent this spring following recent seasonal conditions.
Worm egg counts are a useful tool to measure drench effectiveness. See the sheep Drench Decision Guide on the Wormboss website or read more on the DPIRD website on drench resistance.

Recent livestock disease cases in WA

Eperythrozoonosis (Mycoplasma ovis) causes death in 30 lambs in the Great Southern

Lambs still on their mothers presented with anaemia (e.g. pale gums, weakness) and sudden death.
The lambs had been marked one month prior and given a 6-in-1 and erysipelas vaccination, selenium and vitamin B12 supplementation and drenched against worms. Marking equipment had been disinfected.
Tests showed the lambs were severely anaemic with large numbers of the blood parasite, Mycoplasma ovis (eperythrozoonosis).
M. ovis is transmitted via infected blood (e.g. contaminated needles or surgical instruments) or biting insects such as ticks, flies, fleas and mosquitoes. In conjunction with poor nutrition and a heavy worm burden, the disease in lambs can be severe.
Despite a recent worm drench, the appearance of the intestines suggested prior worm damage.
Good nutrition, parasite control and reducing handling stress of affected animals can reduce losses until animals recover.
Outbreaks of the disease are more likely in spring.
Read more on the DPIRD webpage on eperythrozoonosis.

Weakness and death in lambs in the Wheatbelt due to pulpy kidney (enterotoxaemia)

The 6-8 week-old lambs displayed unusual behaviour before becoming weak and dying. The lambs had been vaccinated against pulpy kidney at marking 5 weeks prior. The flock was fed on hay, lupins and oats.
Intestinal contents tested positive for enterotoxaemia toxin and indicated a significant roundworm burden. Given the abnormal behaviour, blood was also tested for lead toxicity (reportable) and the result was negative.
Pulpy kidney can occur in unvaccinated or incorrectly vaccinated sheep, where there is a sudden change to high carbohydrate, low-fibre feed (e.g. moved to lush pasture/grain) and is more often seen in sheep that are rapidly growing.
Note: a one-off vaccination is generally not sufficient to provide immunity in previously unvaccinated sheep and lambs. Read more on our website on pulpy kidney vaccination. Avoiding sudden changes in feed quality will also help to prevent the disease occurring.

Abscess in flank

Abscess in rump

Abscesses seen in the flank (top) and back/rump (bottom) of a sheep carcass.

Don’t lose profits from vaccination abscesses at abattoir

Abattoir inspectors have noticed a recent increase in the number of vaccination abscesses in sheep carcasses. These can result in downgrading and removal of sections of a carcass, which can be prime cuts, resulting in reduced profits to the producer.
Abscesses are normally seen in the neck, rump, flank, back and inner thigh. Sheep vaccines that are designed to be used subcutaneously should only enter the space just below the hide. This area is the junction between the easily pinched hide and the body. Vaccine should be given high in the neck away from prime cuts.
Using a short needle, angling the needle at 45 degrees to the body and pinching up the hide to stretch the area and injecting are some techniques that can help.
Abscesses can result from bacteria on the needle or a blunt needle, which is more likely to tear the skin allowing bacteria to enter.
Read Animal Health Australia’s factsheet for more information.

1000+ reasons for WA’s high animal health status

WA producers and vets are the frontline of the State’s animal health surveillance team and in 2016/17 producers made over 1000 calls to a vet to investigate and submit laboratory samples when animals showed signs of illness.

These investigations help our livestock industries to maintain access to domestic and international markets by providing evidence that we are free of exotic diseases that may look like common endemic diseases and present with signs like sudden death, lameness, unusual behaviour and abortion.

To find out more about how WA’s surveillance system protects our livestock markets, see the new video, Animal Health Surveillance in WA.

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