Dairy Farming Manual
|What is FMD? (5-12)
1 FMD is:
|What are the signs of FMD? (13-17)
2 The signs include:
|How can your animals get FMD? (18-24)
|How can you treat, prevent and control FMD?
4 You cannot treat FMD.
FOOT AND MOUTH DISEASE (FMD)
Husbandry Unit 10.3:
Note: Numbers in brackets refer to illustrations in the Extension Materials.
This disease spreads very quickly
and outbreaks normally include rapid infection not only of most animals
in a herd, but also of more herds in a region. The death rate in
adult animals is normally low, but big losses occur from the following:
lack of weight gain, reduced milk yield and mastitis, and general un-thriftiness.
|5 FMD is a dangerous disease.
It spreads very quickly from one animal to another
|6 and from one area to another.|
|7 Your cow usually has the disease for 2-3
Only a few cows die from FMD
|8 but you lose money from:
- low weight gain
- low milk yield
even after the cow has recovered from FMD.
Cause of disease (9-10)
The disease is caused by a virus (Foot and Mouth Disease Virus or FMD Virus). Under certain climatic conditions the virus can survive for a long time outside the body and remain infective.
Affected animals (11-12)
All cloven-hooved animals, including
cattle, pigs, sheep, goats, buffalo, deer and elephants (but not horses)
are affected by the disease. The disease is not dangerous to people.
|9 FMD virus causes the disease.|
|10 FMD virus can live for a long time outside the body and still be infective|
|What animals get FMD?
11 All animals with cloven hooves:
cattle, pigs, sheep, goats, buffalo, deer, elephants.
FMD does not affect horses
|12 .......or people.
Signs of disease (13-17)
Infected animals will show drooling, vesicles on the nose and in the mouth, and between the claws as the first signs of disease, normally 1-15 days (average 2-6 days) after exposure to the virus.
The drooling, with long ropes of stringy saliva hanging from the mouth, is a typical sign. Animals consume only liquids or stop eating and drinking completely, they shiver and have high fever. Salivation and lameness, due to vesicles in the mouth and between the claws, are evident. By opening the mouth vesicles may be seen on tongue, palate and other places - or the vesicles have ruptured and left open, bleeding wounds. The fluid contents of the vesicles are highly infective. The ulcers normally heal in 1-2 weeks.
The udder may be affected, with vesicles on the teats and on the udder itself. Infected milk yielding animals show a rapidly decreasing milk production. Young animals may be infected by suckling milk from such cows.
If the animal recovers from disease it normally shows aftermath in the form of hoof deformities, mastitis and decreased milk production and unthriftiness (no weight gain). Abortion and infertility may also be seen after recovery from acute disease.
Disease normally lasts 2-3 weeks
in the animal, and goes through the herd in about 1-3 months. Although
only a few animals die, losses from reduced production during the acute
outbreak, and from the diseases following later, are normally large.
|13 Within 1-15 days after getting
FMD (usually 2-6 days):
Long ropes of stringy saliva hang from the mouth.
|Fever and lameness
16 The virus causes:
- shivering and high fever
- lameness from blisters/ulcers.
Normally the disease goes from animal to animal through the air or by direct contact with virus containing secretions (for instance from ruptured vesicles). Transmission by wind over many kilometres is possible.
Infected pigs excrete large amounts of virus and are considered extremely infectious.
Infected animals, that still did not show any signs of disease, as well as animals that have recovered from disease, may contain and excrete the virus.
Passive transmission by other animals and bedding, by people, vehicles, tools etc is common.
Transmission through milk and meat is highly possible, and pasteurization does not necessarily destroy the virus. Pigs being fed virus-containing meat can easily acquire the disease and readily infect other animals - for instance cattle.
Transmission by A.I. (infected
semen) is possible, but uncommon.
|Low milk production|
|How can your animals get FMD?
18 Liquid from the blisters contains the virus.
19 Vehicles, equipment and you may carry the virus from one animal to another.
|20 Milk and meat can carry the
virus from one animal to another.
Pasteurization does not always kill the virus.
|21 Pigs may eat meat with FMD
They pass on large amounts of the virus which can infect your cows.
|22 In A.I., semen with the virus can pass on FMD but this is unusual.|
|23 The wind can carry the virus from one cow with FMD to another.|
|24 Animals which:
- have the virus inside but do not yet show signs of FMD
- have recovered from FMD
can pass on the FMD virus.
No real cure against FMD exists. As the disease develops treatment may be undertaken to alleviate the condition, such as local treatment of wounds and antibiotic treatment against further bacterial infection.
There are other diseases (for
instance Vesicular Stomatitis) which cause vesicle formation in the mouth
and may be confused with FMD. A safe diagnosis can be made by laboratory
examination of material from acutely sick animals.
How can you treat animals with FMD?
- give antibiotics to stop further bacterial infection.
|How can you know if your animals have FMD?|
Prevention and control
Vaccination is possible and normally carried out on a national (or regional) level. As a rule, immunity after vaccination lasts 6 months. (28)
Many different strains of virus mean that even vaccinated animals may get FMD, because not all strains of virus may be covered by the vaccine used. (29)
Any suspicion of FMD should result
in prompt isolation measures - isolation of infected animal(s) within the
herd and especially isolation of the herd as a whole from other herds.
Not only should animals from infected herds not be moved, but people, vehicles
etc should stay away from other cattle herds and make sure that they only
leave the infected herd after proper cleaning and disinfection of themselves,
their clothes, tools, and vehicles etc. (30-33)
This usually protects your animals for about 6
|29 but there are many types of FMD virus, and
not all may be covered by the vaccine.
Your animals may still get FMD after vaccination
30 If any of your animals show signs of FMD:
- isolate those animals from your herd
- isolate your herd from other herds.
|Disinfection can be carried out with sodium hydroxide, sodium carbonate or acetic acid. Carcasses should be burnt or buried, and premises then thoroughly disinfected. (34-36)|
32 Never move an animal, bedding grass or equipment from an infected herd.
|33 Try to keep people, vehicles etc away from infected herds.|
|34 Disinfect anything - vehicles, equipment, clothes, you - which contacts an infected place or infected animals.|
|35 You can use:
- sodium hydroxide
- sodium carbonate
- acetic acid
Follow the directions on the labels and ask your
extension worker for advice.
|Most countries have special regulations concerning FMD, sometimes including restricted movement of animals, isolation and possibly slaughter of infected animals. (37)|
|36 Burn or bury
dead animals, and bedding and disinfect everything on your farm.
|37 Consult your extension worker
about what you can and cannot do.
You may have to slaughter infected animals.