13/08/2016
FOOT AND MOUTH DISEASE
A highly infections virus disease which can spread very rapidly to other cloven hoofed animals( pigs ,sheep, goats and deer) and to adjacent farms.
Once a herd gets infected the incubation period can be as little as two days. That means there may be only two days between exposure to the virus and clinical signs being seen. That why the disease can be spread very rapidly. An infected cow excretes virus in her urine faeces, milk, saliva and even on her breath. The virus can survive on the ground much longer in winter for up to 30 days but only 3-5 days in summer.
the first sign in an infected herd will be a dramatic drop in yield together with high temperature. Within 24 hours the virus produces large 'vesicles' that is fluid- filled blisters around 2-4cm in diameter commonly seen on the tongue, between the claws of the feet and also occur on the teats.
There may be so many vesicles present that if the tongue is grasped almost all of its covering falls off in your hand. This makes animals drool, uncomfortable on their feet.
If the disease is allowed to progress, affected animals will lose weight rapidly and milk production will suffer.
Mortality may be very high in younger animals (50-60%) due to heart lesions. THERE IS NO SPECIFIC TREATMENT.
It is interesting to note that one of the local " treatment" for foot- and - mouth disease in Southern Africa is to smear the inside of the animals mouth with sodium hydroxide or salt. This is said to reduce the rate of virus shedding and to speed recovery.
If we want to have an eradication policy for the control of the disease ,determining possible sources of infection is extremely important. Imported live animals represent the greatest potential danger. Therefore countries of origin must be strictly monitored to confirm that they are totally free from any risk of foot and mouth. Animal should be quarantined and submitted to regular veterinary inspections.
Imported carcasses and other animal products can also carry infection. Again countries of origin must be carefully monitored. to minimize risks, only boneless meat may be imported as virus is most likely to die in meat which has 'set ' whereas it can survive for much longer in bones. strict regulations should be put in place relating to the storage of swill or waste food and to ensure that it should be cooked in approved equipment for at least one hour prior to feeding other animals. The virus is so infectious that air -borne spread is also a possibility.
Control is based on identification and slaughter of infected herd. Restrictions on the movement of all livestock within a 1km radius known as the infected area.Controlled areas may be established depending of the evolution and spreading of the disease.
Slaughtered carcasses plus bedding ( manure) and other infected material must either be burnt or buried under six feet of earth. The farm must be thoroughly disinfected and cannot be restocked for a further determined period.
Because of the rapid spread of infection,early identification of disease is vital and is a LEGAL OBLIGATION to report even SUSPECTED CASES of foo t- and - mouth to the veterinary officers immediately.
If the situation is getting worse, stocks of vaccine must be made available to carry out a "ring Vaccination" of animals around an infected area. Should the disease ever get totally out of control; there are at least four good reasons why it is hoped that these measures will never be used.
First it's all an economy or sector whether it is big or small will suffer huge losses.
Second, because there are a variety of different STRAINS of foot- and - mouth , the vaccine in use may not be totally effective.
Third, vaccinated animals can become carriers shedding infection to other stock.
Finally, and by no means least important, to give full protection vaccination would have to be carried out each year, and in the long this would be much more expensive than the current Slaughter Policy.
SC
