Aujeszky's disease

Aujeszky’s disease is a contagious viral disease caused by a herpesvirus called Pseudorabies virus (PRV). The most common form is an acute febrile syndrome that mainly affects pigs (the main reservoir for the virus), though many other animal species are also susceptible.

The virus spreads to the airways, nervous system, and in pregnant sows, the fetus. It is widespread throughout the world and its effects have considerable economic impact.

Classical swine fever (CSF)

CSF is considered the second most serious of all contagious diseases of pigs and wild boars, after aphthous fever. It is a major threat to pig production, with serious socioeconomic consequences.

The disease is caused by an enveloped RNA virus of the genus Pestivirus in the Flaviviridae family. CSF cannot be transmitted to humans and manifests in different ways according to the virulence of the infecting virus and the animal's stage of development.

Foot and mouth disease (FMD)

FMD is a highly contagious viral disease that affects all cloven-hoofed animals, and is widespread throughout the world. FMD cannot be differentiated clinically from other vesicular diseases such as swine vesicular disease (SVD).

The virus is a member of the genus Apthovirus in the family Picornaviridae. There are seven serotypes of FMD virus: O, A, C, SAT 1, SAT 2, SAT 3, and Asia 1. Infection with any one serotype does not confer immunity against other serotypes.

Hepatitis E virus (HEV)

HEV belongs to the family Hepeviridae. HEV consists of one serotype that is divided into four genotypes. Only genotypes 3 and 4 have been demonstrated to infect pigs. Genotype 3 represents the most frequently occurring genotype in pigs in industrialized countries.

Mycobacterium avium

Mycobacterium avium belongs to the M. avium complex (MAC), which comprises 28 serotypes. Serotypes 1-6, 8-1, and 21 belong to M. avium subsp. avium (MAA), most of which can infect both humans and pigs. MAA infections in pigs are mostly subclinical. The only visible signs are granulomatous lesions that occur in the lymph nodes of most animals.

Currently, diagnosis of MAA infections in pigs is based on palpation and the incision of lymph nodes at slaughter. This traditional method has a disadvantage, as MAA has been isolated from lymph nodes without lesions and these infected animals would thus not be detected. Additionally, infections with non-mycobacterial species such as Rhodococcus equi can induce granulomatous lesions as well and have resulted in misdiagnosed animals. Furthermore, the current detection method is both cumbersome and time consuming.

Risk-based surveillance for MAA, based on serology, can improve MAA control and therefore enhance the health status of the herd with regard to M. avium. With serology testing, MAA infections in herds can be controlled much more efficiently and effectively than with the traditional method.

Parvovirosis/Porcine parvovirus (PPV)

Stillbirth, mummification, embryonic death, and infertility (SMEDI) is a common contagious disease in swine that is found in many countries around the world. It is caused by the single-stranded DNA porcine parvovirus (PPV), which belongs to the Parvoviridae family. The infection starts in one or more fetuses and then spreads inside the uterus to most of the litter, so live piglets can be delivered together with mummified fetuses.

Porcine reproductive and respiratory syndrome (PRRS)

PRRS is a highly contagious disease found in swine (pigs and wild boars). It is caused by a virus belonging to the Arterivirus family that also contains the causative agents of equine arteritis and simian hemorrhagic fever. The PRRS virus is a small (50–60 nm), enveloped RNA virus with at least two different membrane proteins at its surface, which are probably the antigens that elicit the serological responses detected in infected pigs.

The PRRS virus has immunosuppressive activity and kills the macrophages in the lung, inside which it replicates. This probably helps compromise pulmonary resistance to other infectious viruses and bacteria. Viral particles are secreted in all bodily secretions, including nasal secretions, feces, and sperm, as well as in aborted fetal tissue and placenta. This disease is spread throughout the world and affects domesticated pigs in particular.

Salmonellosis

Salmonellosis is an infection caused by Salmonella bacteria. The presence of salmonellosis has been identified in countries throughout the world, but appears to be most prevalent in areas of intensive animal husbandry, especially occurring in pigs, calves, and some types of poultry.

The disease can affect all domestic animals; however, young animals and pregnant or lactating animals are the most susceptible to the disease. The clinical signs that may be seen are abortion, arthritis, respiratory disease, and acute septicemia. Enteric disease, often presenting as a bloody, watery diarrhoea with pyrexia, is the most common clinical manifestation.

Swine influenza (SIV)

Swine influenza is a highly contagious viral infection of pigs. The infection is transmitted when an animal comes into contact with secretions containing viral particles, notably in aerosols generated by coughing, sneezing, and the projection of nasal discharges.

Toxoplasmosis

Toxoplasmosis is caused by the protozoan parasite Toxoplasma gondii, which belongs to the family of the Sarcocystiidae. Toxoplasma infections are widespread in humans and many other species of warm-blooded animals, including pigs, sheep, and goats. Occurrence is worldwide; however, the prevalence in human and animal populations varies greatly among countries.

Trichinellosis

Trichinellosis is a zoonotic disease that occurs worldwide and is caused by the nematode Trichinella. The roundworm Trichinella spp. infects many carnivorous and omnivorous animal species, including domestic pigs. Currently, 11 different subspecies have been recognized in this genus. The species that are of main importance in Europe are Trichinella spiralis, Trichinella britovi, Trichinella pseudospiralis, and Trichinella nativa. T. spiralis is of main concern because domestic pigs show a high susceptibility to this genotype. T. britovi is mostly found in wildlife.