African Swine Fever (ASF): Important Facts

Pig rearing remains a lucrative business, but it is often disrupted by diseases.

One of the diseases that attack pigs is the African swine fever (ASF). The disease is characterised by loss of appetite; the skin under the ears, snout, legs and abdomen becomes dark blue, and the animals vomit and cough.

The pigs may further bleed from the nose and rectum, have difficulties in breathing and they will diarrhoea. In short, African swine fever is the most deadly pig disease.

The viral disease is highly contagious and affects domesticated and wild pigs and warthogs. It is transmitted mainly through direct contact with already infected pigs, their body fluids or their droppings, indirectly by ingestion of infected feedstuff especially garbage and by ticks that are vectors of the causing virus.

Sadly, African swine fever has no treatment and can wipe out an entire pig farm. No vaccines have been developed but several biosecurity measures can be practised to minimise its spread. Watch out for biting flies, ticks, and limit the number of vehicles and people visiting your farm since they are other possible carriers of the disease.

In fact, to be safe, provide cover clothing material for visitors and ensure equipment used on your farm is clean. Make sure your visitors disinfect their shoes, while vehicles run through a disinfectant. If possible, fence your pig farm to keep away wild animals like warthogs, forest hogs and domestic pigs and their ticks.

Pig farmers further need to look out on housing structure, stocking density and feeding to curb the disease.

Also, be on the lookout for outbreaks since clinical signs can always be seen. In some cases, the disease may be in mild strain that infected pigs possibly do not show typical signs making it unrecognisable for some time.

In other circumstances, it may be severe, described by high fever and sudden deaths. African swine fever has 100% mortality rate and diagnosis is made from clinical signs and collecting samples of spleen and blood for lab analysis.

This is because in the body of susceptible animals, the virus dominantly concentrates in the blood and minor areas like meat, bones and skin.

Besides biosecurity measures, slaughter and dispose pigs infected with the disease and report cases for action by various veterinary bodies.

If the vet confirms the disease from laboratory diagnosis, the area of the outbreak should be quarantined to enclose the causative agent and to prevent spread. Thereafter, if your farm is infected, disinfect your premises thoroughly and do not re-populate for about two weeks.

Piggeries should have good drainage systems coupled with high standards of hygiene to help minimise disease attacks. Parasites being a major problem in the pig industry, farmers should control internal parasites like worms and external parasites like mites and lice, which stagger production levels.

About author:

Felix Opinya - works in The Department of Animal Science, Egerton University.