Tapuwa Mashangwa Agriculture column
IT is always better to prevent than to cure and in agribusiness the curing part especially when bacterial, viral or fungal outbreaks are involved, always comes with direct and indirect losses that greatly affect the growth of the agricultural sector. Foot and mouth disease (FMD) is an infectious disease caused by a virus. It affects wild and domestic cloven-hooved animals (cattle, sheep, pigs, goats, and deer) and also elephants, hedgehogs and rats.

It doesn’t usually cause death of animals, except in severe cases in older animals and it sometimes can cause heart failure in lambs.

Animals can recover after 2-3 weeks but the discomfort is severe and long term health effects are common.

Secondary infections can sometimes worsen the effects of FMD. In cattle it is particularly serious for the long-term health of the cow and can lead to loss of milk yield, chronic mastitis, abortion, sterility and chronic lameness and sometimes chronic heart disease.

FMD is spread mainly by the movement of infected animals and the movement of infectious material carried on the wheels of cars, or on people’s boots and usually spreads between animals via contact with fluid from blisters, saliva, milk and dung either directly or from contaminated objects and in some cases can be spread via airborne virus if the climatic conditions are right.

The main symptoms in cattle are due to the effects of blisters (vesicles) that form in the mouth and around the tops of the hoofs — these then ulcerate between the cleat (what would be toes on humans) and also just above the hoof.

These are very sore and painful to the animals and so cattle show signs of lameness due to pain in the feet — so some cows may be reluctant to rise — and also will salivate excessively due to producing saliva to ease the pain of the blisters in the mouth and also because it is sore to swallow.

They tend to show excessive tongue movements and smacking of the lips. In the initial stages before the blisters develop then the animal may stop eating and will have an elevated temperature which can lead to depression in the animal and decreased milk yields in dairy cows.

Not all animals show all of the clinical signs of FMD at any one time.

The only way that you can definitely confirm it is with clinical tests. (Other diseases can produce ulcers in the mouths of cows).

One of the main differences from other diseases in cattle is the ease with which the disease can spread and the number of animals affected on a farm at any one time.

The welfare implications of the disease are probably greater than for most of the other endemic diseases. In other species the symptoms in pigs are relatively similar and pigs produce more viruses per animal than cattle.

The disease is less severe in sheep and the lesions tend to be more difficult to spot.

In the event of an outbreak disinfection of people and equipment coming into contact with infected animals is very important. The disease control policy is to slaughter all animals on the affected remise and any others that may have been in contact with infected animals.

Movement restrictions are put in place with protection and surveillance zones. There is an option for vaccination that could be taken up in addition to slaughter.

Vaccination can be used as part of a wider control strategy for foot and mouth but not as an overall solution due to several limitations.

The vaccination must be tailor-made for a particular strain as immunity is virus type-specific. This causes delay in the vaccination programme. Current vaccines only provide six months protection or limited period protection at best.

There is a danger that vaccinated animals, although protected against the disease, may become carriers if they are exposed to a new outbreak of the virus.

FMD survival depends on the conditions and the material the virus is harboured in. Survival times vary from 14 days in dry faeces up to around a month in urine.

It’s possible that the virus could have survived for the past month or longer if harboured in slurry. Survival time on the ground varies from three days in summer to 28 days in winter.

The cost of preventing an outbreak of FMD is lower than that involved in the posterior management of an outbreak of the disease. Efficiency and effectiveness in FMD management is paramount and once the requisites are strictly adhered to an outbreak is avoidable.

Like all management policies and requisites, once followed the structure and functionality is secured and its future is green.

l The writer is Engineer Tapuwa Justice Mashangwa, a young entrepreneur based in Bulawayo, founder and CEO of Emerald Agribusiness Consultancy. He can be contacted on +263 739 096 418 and email: [email protected]