Aujeszky's disease – the potential danger in raw pork

The primary hosts of the pathogen are pigs and rats. Pigs infect each other through direct contact via droplet transmission. In Germany, Aujeszky’s disease has been considered eradicated in domestic pigs since the 1990s. However, the virus continues to occur in wild boars.

The most common sources of infection for dogs and cats are raw or undercooked pork and hunting byproducts. The virus is ingested with the infected meat, enters the digestive tract, and multiplies there. It then spreads throughout the entire body via the bloodstream. Further replication occurs in the brain, leading to inflammation of the brain and spinal cord (see article on meningoencephalitis) with destruction of the nervous tissue. Deaths occur time and again, particularly among hunting dogs.

In pigs, the disease is life-threatening only to suckling piglets. These usually die without any noticeable symptoms. Piglets older than ten weeks exhibit muscle twitching, as well as movement and behavioral disorders. Older pigs, on the other hand, are the primary virus shedders. They mainly exhibit respiratory symptoms and experience stillbirths.

In all other mammals, the disease is always fatal. Within three to four days of infection, the first symptoms already appear in affected animals. Affected animals are noticeable due to extreme vocalizations, restlessness, excessive drooling, and in some cases vomiting. As the disease progresses, muscle twitching throughout the body, extreme itching, aggression, movement disorders, and convulsions develop, which is why the disease is called pseudorabies. Death usually occurs 12 to 48 hours after the first symptoms appear.

If you notice any of the symptoms described above in your pet, please contact your veterinarian immediately, even if the animal has already died, as even a suspected case of Aujeszky’s disease must be reported to the veterinary office.

Your veterinarian will make a preliminary diagnosis based on the characteristic symptoms in conjunction with your preliminary report. If you know what your animal ate or which potential carriers it came into contact with, testing the carriers or the meat may provide evidence. Otherwise, direct detection of the virus is only possible in a dead animal. Antibodies can only be detected in the blood four to five days after infection. Since the animals usually die before then, this test is not practical.

Based on current knowledge, there is no treatment available for dogs and cats. Once the disease breaks out, it always leads to death within 12 to 48 hours. Dogs or cats presented at a veterinary clinic with clear, severe symptoms of pseudorabies should be euthanized to spare them further suffering.

Aujeszky’s disease is a notifiable animal disease that is controlled by the government in Germany and many other countries. On pig farms, regular blood tests are conducted, and quarantine measures are implemented when necessary. To prevent the spread of the disease, it may also be necessary to cull animals as a precautionary measure. This process is referred to as culling.

For pigs, vaccination is an option in heavily infected areas. However, this does not protect against infection, but only against the symptoms, so that the farmer does not incur any losses. Infected pigs thus still represent a source of infection, which is why vaccination is prohibited in Aujeszky-free countries, such as Germany.

There is no vaccine available in Europe for dogs and cats. However, adhering to certain measures can reduce their risk of infection. Since pigs are the primary carriers and shedders of the virus, dogs and cats should not be kept together with them. Hunting dogs should be consistently kept away from wild boar carcasses and from other potentially infectious material, such as hunting waste. Furthermore, when feeding pork, care must be taken to ensure that it is always thoroughly cooked, as heat reliably kills the pathogen.