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Recognising foot and mouth | AG0012 |
Mike Harrison, Melbourne
February, 2002 |  |
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This Agriculture Note describes how to recognise foot and mouth disease. Australia has remained free of foot and mouth disease for more than 100 years. Strict quarantine regulations that prohibit the entry to Australia of animals and animal products which could carry the infection are our first line of defence. If foot and mouth disease did enter the country, a small outbreak could possibly be eradicated quickly but at a high cost. For every day before the disease was diagnosed, the difficulty and cost of eradication would increase enormously. This is because foot and mouth disease spreads rapidly.
Most countries would ban our livestock and livestock products as soon as foot and mouth disease was found. These restrictions would not be lifted until Australia could prove that the disease had been eradicated.
Signs of the disease
Early recognition of the disease is of vital importance. All farmers and other people who have contact with livestock must know the signs:
- All cloven-footed animals can be affected (cattle, sheep, goats, pigs and deer). The animal appears to be depressed, fevered or ill-at-ease before any definite signs appear.
- Lameness is a common early sign, especially in pigs. All feet are affected at once and the animal moves slowly. Dairy cows may show a rapid drop in milk production, and have sore teats.
- Affected cattle may drool long strings of sticky saliva. Drooling cattle often smack their lips. This can be both seen and heard.
- Blisters (vesicles) appear within a few hours after the animal becomes sick. They may appear around the tops of the claws or between them, on udders and teats, and on the nose, lips, gums, tongue and inside the mouth.
- The blisters vary in appearance. On the surface of the tongue of cattle they may rapidly develop to a length of 20-50 mm or more, with an irregular edge, and the surface of the blisters may be much paler than the surrounding tissues.
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Figure 1. Unruptured blister on tongue
Figure 2. Ruptured blister on tongue
In contrast, blisters on the feet of sheep may be very small, and rupture quickly. Blisters contain a clear, watery, usually blood-tinged fluid. The blisters usually rupture about 24 hours after they form. The fluid leaks out and raw, moist tissue can be seen at the base of the blister. The rim is usually ragged. In cattle, damage to the tongue may be so severe that most of the lining of the tongue peels off. (Small blisters may be difficult to recognise after they rupture.) Later, the ruptured blisters begin to heal. At this stage they are hard to tell from other types of healing sores. The animal may appear to recover, or remain noticeably sick for very long periods. Few animals die.
Figure 3. Raw surface left after “skin” of the tongue has peeled away.
The following points are important
- Foot and mouth disease should be suspected whenever several animals become sick at the same time. The signs of the disease are quite variable, and one should not assume that the disease is absent simply because it does not follow exactly the description given.
- Foot and mouth disease does not usually kill many animals. It is a very debilitating disease from which animals may take many months to recover.
- The virus is in all tissues, secretions and excretions of infected animals. Milk from infected cows can contain enormous amounts of virus. Infected pigs breathe out large amounts of virus into the atmosphere, and can infect large numbers of other stock in this way. Urgent action is needed to prevent all possible means of spread.
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Several diseases of livestock resemble foot and mouth disease. Don't decide on your own whether foot and mouth disease is present. If you are in doubt, contact your local DPI office, a private veterinarian, or Disease Watch Hotline 1800 675 888 (free call).
Further information
Videos on exotic animal diseases are available from State and Territory departments of agriculture.
The advice provided in this publication is intended as a source of information only. Always read the label before using any of the products mentioned. The State of Victoria and its employees do not guarantee that the publication is without flaw of any kind or is wholly appropriate for your particular purposes and therefore disclaims all liability for any error, loss or other consequence which may arise from you relying on any information in this publication.
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