Animal disease threats mount as wet weather impact grows

Beef Central, 05/03/2012

With many parts of Eastern Australia affected by extreme and prolonged wet weather, Animal Health Australia has this week issued warnings to livestock producers to be on the lookout for heightened risks to animal health and property biosecurity associated with such conditions.

One of the first and most obvious examples is often seen in stock feed and feedstuffs.

In wet and humid conditions it is especially important to keep feed in a clean, dry storage area and to keep stores covered to prevent feed from becoming wet and mouldy.

If waterlogged conditions mean that additional feed must be bought, always make sure it is fit-for-purpose by insisting on a Commodity Vendor Declaration, AHA advises.

Precautions also need to be taken against feeding spoiled hay when providing supplements for hungry stock, to avoid scouring outbreaks. Dispose of old, mouldy or contaminated feed safely, keeping it away from livestock and securing it from pests.

More tips on keeping feed and water safe for livestock during prolonged wet weather can be found here.

AHA has prepared the following brief snapshot of other potential animal health challenges likely to be faced by cattle, sheep and horse owners and managers in coming weeks:


Wet weather often brings more frequent tick, fly and worm infestations, which are responsible for deadly diseases such as tick fever, bovine anaemia and bovine ephemeral fever (BEF, or three-day sickness).

It is a good idea to inspect livestock regularly in current conditions and to check with a vet for available vaccines and drenches. If any unusual signs are seen in animals, stock owners should call the Emergency Animal Disease Hotline on 1800 084 881.


Facial eczema

The risk of facial eczema in cattle is greatest in late summer and autumn when periods of rain or high humidity occur in combination with high night-time minimum temperatures. Facial eczema is caused by toxic levels of a fungus which lives mainly on ryegrass, damages the liver of cattle and in some cows, causes skin lesions.

The greatest cost of the disease to dairy farmers is from the 80pc of cows which have liver damage, but no skin lesions. These cows will have lower milk production and fertility.

With increasing fungal spore counts and cases of facial eczema reported across Victoria’s Gippsland, Dairy Australia is urging farmers to closely monitor their pastures and start feeding a preventative zinc supplement to their milking cows. Similar symptoms are seen in beef cows in southern regions.



Footrot thrives in warm wet weather, and this year is no exception. After many years of keeping a lid on the disease, farmers from NSW to WA are reporting elevated levels of the virulent form of footrot in sheep. Fortunately the virulent form of the disease is much less prevalent in cattle.

It takes only one affected sheep to infect the entire flock and, once established, virulent footrot is very expensive to control and eradicate – especially since there is currently no available vaccine on the Australian market.

It is advisable to check lame sheep and investigate immediately if it is suspected the disease may be present. Early detection is critical, because it can prevent lameness and spread of virulent footrot within the flock as well as to other properties.

Like many other diseases, virulent footrot most often arrives ‘on the back of truck.’ Place any new sheep into quarantine, inspect them closely on arrival and always purchase with a fully-completed National Sheep Health Statement. If the animals have come from an area where footrot is known to be prevalent, treating them upon arrival to the property before placing them into quarantine is wise.


Last year, an epidemic of mosquito-borne arboviruses caused a combination of three diseases in horses – Kunjin virus, Murray Valley encephalitis and Ross River virus – which killed more than 90 animals.

Mosquitoes are known to breed quickly in hot, wet conditions and horse owners are urged to remain highly vigilant. Ensure that water collected in buckets and other receptacles is properly drained and not left as an extra breeding ground for mosquitoes.

Owners should try to prevent their animals from being bitten by insects through simple husbandry practices including rugging, fly masks and using registered insect repellents.

Ensuring that horses are kept in good condition will help build a strong immune system and minimise the risk of infection from arboviruses.

More information on preventing wet-weather diseases in horses can be obtained here.

For more biosecurity tools and tips, go to and download the Farm Biosecurity Plan or Manual relevant to your livestock industry. For specific advice, AHA advises speaking to a veterinarian or local animal health officer.


Weeds challenge

In addition to animal diseases, prolonged and extreme wet weather can present farm biosecurity challenges in the form of weeds. Water flows often bring weed seeds with them, some of which can seriously affect the health and welfare of livestock. Others will take over and reduce the nutritional value of grazing land for stock.

Landholders should be especially mindful of weeds arriving from upstream districts in floodwaters, including rarely-seen toxic plant seeds that result in new infestations. If stockowners notice any unusual weeds or behavioural changes in livestock, they should seek advice urgently.

Weed seeds can be carried on or inside animals, to be deposited later elsewhere, and establish in grazing areas. It is important to maintain inspection controls on all livestock that have grazed on recently-flooded pastures. If they are rejoining a property’s main herd or flock, they should be isolated for about ten days to ensure they don’t drop weed seeds into regular grazing lands.

Inspect both the animals and their faeces, to help prevent harmful weeds establishing on the property. More details about Pests and Weeds can be found here.

  • Farm Biosecurity, a joint program managed by Animal Health Australia (AHA) and Plant Health Australia (PHA), is a national education and engagement campaign providing producers with information and tools to reduce the risk of diseases, pests and weeds. Producers are encouraged to check their properties regularly and if they see anything unusual to call the Exotic Plant Pest Hotline on 1800 084 881 or the Emergency Animal Disease Watch Hotline on 1800 675 888. Click here for further information


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