Porcine Brucellosis

Introduction

Porcine brucellosis is caused by the organism Brucella. suis and is prevalent in pigs in Europe, Australia and Asia. It is, however, absent from the UK and Ireland.

Infection is via the faeco-oral route or the venereal route and transmission is due to introduction of live pigs with the disease or infected semen or ova. Lateral spread may also occur in younger pigs. Sows may remain carriers of the disease for many months and pass this on to up to 10% of their progeny.

Clinical Signs

Depend on when the infection occurs. Sows infected at service (by infected semen) will abort in the first trimester, whereas sows infected during pregnancy will usually produce mummified, stillborn or weak pigs depending on which stage of pregnancy the infection occurred. Endometritis and vulval discharge are other signs that may be seen.

In males, testicular abnormalities may be seen if they are excreting the bacteria in semen, such as enlargement and abnormal shape. Orchitis and epididymitis will occur 7 weeks after infection and then testicular atrophy may be present within 3 months.

Joints and bones may be involved in both sexes which may cause lameness and swelling. This can be severe enough to warrant their destruction on humane grounds.

Diagnosis

Isolation of the organism from lymph nodes and culturing is a common diagnostic tool. Large scale surveillance is best performed using the Rose Bengal test plate and indirect ELISA.

A PCR has been used but some infected animals are antibody negative.

Control

Testing then slaughter is required immediately where the disease is exotic.