Foot-and-mouth disease: Its impact on livestock

The disease is an obstacle to development of the livestock sector because of its adverse effects to livestock production, trade in animals and animal products and a threat to developed countries where it has been controlled.

FMD was first reported in Tanzania in 1927 in Arusha region and Kahama district. Since then it has been reported every year, mostly during the dry season and immediately after dry season, when livestock as well as wildlife movement increases for search of pasture and water.

Experts say the disease is characterized by high fever, loss of appetite, salivation and vesicular eruptions on feet, mouth and teats. The severity of clinical signs varies with the strain of virus, the exposure dose, age and breed of the animal, host species and immunity of the animal.

Speaking with The Guardian this week, Central Zone Veterinary Centre in charge Daniel Mdetele said the disease affecting all cloven hoofed animals, both domestic and those in the wild, is caused by the foot-and-mouth disease virus (FMDV).

Domesticated animals susceptible to the disease include cattle, pigs, sheep, goats and water buffalo. Species of cloven-hoofed wildlife may also become infected, and the virus has occasionally been noticed in other species as well.

The disease, he said, has got very high morbidity but characterised by low mortality, which is mostly found in young animals and its contagious nature of FMDV and the associated productivity losses make it a primary animal health concern worldwide.

Increased animal movements for slaughter around the end of the year and during religious festivals in the country is considered one of the reasons for its spread in the country.

During such times, animals are immune-compromised because of insufficient water, pasture and long distance movements.

“It is at this time when animals from different places come into contact, thereby increasing the risk of spreading the disease,” argued Mdetele.

The regional veterinary boss also noted that major problems in controlling FMD in Tanzania and why it was considered the most dreadful viral disease are its high contagiousness, wide geographical distribution, broad host range, its ability to establish carrier status, antigenic diversity leading to poor cross-immunity, and relatively short duration of immunity.

But poor surveillance and diagnostic facilities, as well as inadequate control programmes, add to the challenges in controlling the disease in the country.

Besides causing direct losses to livestock keepers, it also causes indirect losses in terms of severe trade restrictions, impacts which may be higher than direct losses.

Tanzania’s economy is mainly based on agriculture, a sector that employs about 85 per cent of its population. Livestock production, which has been increasing in the past years, is limited by disease occurrences, FMD being among them.

Tanzania is endowed with a large number of animal resources, heavily contributing to the well-being of its people by providing food security, employment, raw materials, transport, and manure for crop production.

According to the 2007/2008 livestock census, the country has a total of 2,329,942 households raising livestock.

The country ranks third in Africa in terms of cattle population after Ethiopia and Sudan, with 21,280,875 cattle; goats (15,154,121); sheep (5,715,549), and pigs (1,584,411).

Yet, livestock diseases are threatening the survival of this important resource, impacting on a large number of households.

The livestock subsector’s contribution to total GDP has been recorded as 4.7 per cent, growing at a rate of 4.2 per cent, according to the 2007/2008 livestock census.

Out of the livestock share of GDP, 40 per cent comes from dairy cattle, 30 per cent from beef cattle and the remaining 30 per cent from goats, pigs, poultry and game production.

The subsector’s contribution is considered far below what would have been expected and most shortcomings can be attributed to the presence of animal diseases that affect production and impact on local and international trade in animals and animal products.

FMD affects livestock production in various ways. Normally the affected animals, because of the nature of lesions on the feet and mouths, cannot eat well, much as it is difficult to move the animals to grazing land, resulting in lost weight.

They also become unable to breed as pregnant animals can abort, while milking animals they cannot produce milk. On the other hand, working animals cannot be used for ploughing or pull carts.

“Moreover, because of animal welfare most livestock keepers cannot stand the situation, hence they will start treating clinical signs at any cost for the animals to get well.” he said, adding that the cost is a great burden to farmers.

Because the disease has been controlled in developed countries and the detrimental effect of the disease to those countries cannot be tolerated, stringent measures are imposed preventing animals and animal products from developing countries where there could be a very good market.

Unfortunately, foreign investments in livestock production and the industrial sector associated with livestock and livestock products are not directed to Tanzania because of fear that there will be lack of a market for produced products to American and European markets.

But Mdele observed that modern technology on animal production and processing of very valuable resources cannot be brought to developing countries from foreign investors who have capital and technology.

However, FMD control is possible and has been achieved in some sub-Saharan African countries like Botswana, South Africa, Zimbabwe and Namibia.

“These countries are trading their animal products with industrialized countries and the livestock subsector is contributing very substantially to their countries, economy,” he said.

For Tanzania to control FMD there is a need for investment in educating livestock keepers on the importance of controlled livestock movement and creating a conducive environment which will prevent livestock keepers from moving from one place to another.

This can possibly be achieved through introducing pasture production and management to livestock keepers and other investors who will produce grass and folder which can be used all the year round in the same area. Additionally, water should also be available in those areas, according to the veterinarian.

He noted that these can be implemented in disease free areas where animals from other places cannot be introduced without permission. Also animals in other places should be vaccinated every year after matching the strain of virus circulating in the area with vaccine strain.

In addition, there should be controlled animals movement all over the countries and instead of moving animals for very long distance for trading and slaughtering there is a need to establish livestock markets and processing industries in areas where animals are kept.

To be much safer, instead of moving animals only meat and other products should be moved, as this will help in controlling the disease as well as reducing the cost of transporting live animals and environmental destruction and pollution in cities and towns by animal processing leftovers.

In addition, the spread of other zoonotic diseases from one place to another will be limited.