China's agriculture ministry on Thursday reported an O-type foot-and-mouth outbreak on two pig farms in southern Guangdong province.

The outbreak infected 327 of the 450 hogs found on those two farms in Zhongshan city, Guangdong, China's Ministry of Agriculture and Rural Affairs said in a statement on its website.

Local authorities culled all 450 hogs following the outbreak.

Foot and mouth disease

FMD is a vesicular disease. There are four vesicular diseases of pigs which are difficult or impossible to differentiate clinically: FMD, swine vesicular disease (SVD), vesicular exanthema (VES) and vesicular stomatitis (VS). Of these, FMD is the most widespread and important with SVD being of secondary importance in some regions (e.g. the EU).

This disease should always be considered if sudden widespread lameness appears. In all countries it is notifiable and must be reported to the authorities with all speed.

FMD is the most important restraint to international trade in animals and animal products. Consequently, large sums of money have been invested in control and eradication programmes and also into research. As a result more is known about the FMD virus than about almost any other animal infection.

It generally produces severe disease in pigs.

If you live in an FMD fringe area that is also free of SVD you should be aware of what early clinical signs would make you suspicious and what you should do if you suspected them in your herd. If you farm in an endemic area or a fringe area in which SVD is present then you should try to be more knowledgeable.

If you farm in an FMD-free country that takes sound precautions against its entry, the risk to your herd is negligible (unless you farm in California where vesicular exanthema may pose a very small risk).

Among farm animals, pigs, cattle, sheep, goats and deer are susceptible. In addition, wild and domestic cloven hooved animals such as hedgehogs and rats are also susceptible as are elephants.

Clinical signs

• Sudden widespread lameness.
• Affected pigs salivate.
• Blisters or vesicles are evident on the skin of up to 30mm in diameter. Common sites are:
  • top of the claws;
  • heels;
  • nose;
  • tongue;
  • lips;
  • teats of recently farrowed sows.
• Within 24 hours many of the vesicles will have burst.
• On the lips and teats they may leave shallow erosions but on the coronets of the feet secondary infection and trauma may convert them into raw jagged-edged ulcers.
• Chomping of jaws.
• Inappetence.
• Depression.
• Fever of about 40.5º (105ºF).
• Thimbling (complete loss of hooves).
• Abortion in sows.
• Death in severe cases.

Sows

• Abortion.
• Piglets
• Increased morality (this is often the first sign).
• Cardiac arrest.

Boars

• May stop serving sows.
• Lameness.

The early signs of swine vesicular disease (SVD) when it is severe, are indistinguishable from FMD so you should suspect it too.

Further Reading

Click here to learn more about FMD