Bovine Viral Diarrhea/Mucosal Disease is an infectious disease of cattle caused by a virus. In humans, the virus does not cause disease.

The disease is spread worldwide

Cattle, sheep, goats and wild ruminants

Transmission mainly occurs via persistently (permanently) infected animals (PI animals). These animals are already infected in the womb and excrete viruses throughout their lives via all bodily excretions and secretions.

The majority of infections with BVD viruses are asymptomatic. Diarrhoea, fever, respiratory diseases, mucosal erosions, reluctance to eat, reduced milk yield and fertility problems are possible. Pregnant animals can reject, give birth to malformed or weak calves. A particular variant of the disease is mucosal disease, which can be fatal.

There is no therapy against the BVD virus

Bovine viral diarrhoea is a notifiable animal disease. Vaccination against BVD is prohibited in Austria.

Austria has been officially recognised as free from bovine viral diarrhoea since 17 February 2022. Risk-based monitoring of cattle farms via milk and blood samples is carried out annually.

Bovine viral diarrhoea/mucosal disease is one of the most economically significant infectious diseases of cattle worldwide. Many countries have opted for active control and surveillance programmes for BVD/MD. The disease is caused by a pestivirus, family Flaviviridae, and is spread worldwide. Host animals are cattle, sheep, goats and wild ruminants.

BVD is mainly transmitted via persistently (permanently) infected animals (PI animals). They are the most important source of virus spread. The development of a PI animal occurs through infection of the unborn calf via the dam between the 40th and 120th day of pregnancy. At this time, the foetus's immune system is not yet fully developed, an immune tolerance to the virus develops, the animals remain infected throughout their lives and excrete the virus. Excretion takes place via all bodily excretions and secretions.

The majority of infections with BVD viruses (BVDV) are asymptomatic. Diarrhoea, fever, respiratory diseases, mucosal erosions, reluctance to eat, reduced milk yield and fertility problems are possible. Pregnant animals can reject, give birth to malformed or weak calves.

Mucosal disease (MD) occurs as a special disease variant. It occurs when a PI animal is also infected with another virus strain. MD is characterised by a severe course of the disease and is fatal. Symptoms of MD are bloody diarrhoea, high fever, mucosal erosions and ulcerations (on the muzzle, nose and interdigital cleft).

To control BVD, virus shedders (PI animals) in the herd are removed to protect the herd from new infections.

Die Diagnose von Boviner Virusdiarrhoe ist sowohl direkt (Erregernachweis) als auch indirekt (Antikörpernachweis) möglich.

Probenmaterial für den Erregernachweis mittels PCR oder ELISA: 

• Blut (Serum/Plasma)
• Gewebe (Ohrstanze)
• (veränderte) Organe

Probenmaterial für den Antikörpernachweis mittels ELISA:

• Blut (Serum/Plasma)
• Milch (Einzel- und Tankmilch)

Eines der wichtigsten Ziele in der BVD Diagnostik ist die rechtzeitige Erkennung eines PI-Tieres. Bei der serologischen Untersuchung durch maternale Antikörper (Antikörper, die von der Mutter über Kolostralmilch an Jungtiere weitergegeben werden) können BVD-Viren im Blut maskiert werden, wodurch eine frühzeitige Erkennung nicht mehr möglich ist. Diese sogenannte "diagnostische Lücke" spielt bei der Untersuchung von Gewebeproben keine Rolle und die Erkennung und Ausmerzung der PI-Tiere ist bereits in der ersten Lebenswoche möglich. Ebenso problematisch ist der zeitlich verzögerte Anstieg von Antikörpern nach einer BVD Infektion. BVD-Antikörper sind erst ca. ab dem 7. Tag nach der Infektion nachweisbar. Bei der Untersuchung der Tankmilch ist diese zeitliche Verzögerung noch größer.

Für die PCR Diagnostik aus einer Blutprobe bzw. bei der Untersuchung einer Ohrstanze mittels PCR gibt es keine diagnostische Lücke.