A setback for the eagle-owl family of Leuven. A few months ago, three eagle owl chicks were left behind parentless. First, the mother bird disappeared from the scene while days after their father bird was found dead. The team of Wildlife Health Ghent examined the father bird and looked for a cause of death.
Eurasian Eagle-Owl (Bubo bubo) (C) Unsplash
A necropsy brought clarity. Several white spots were seen on the liver and spleen, pointing towards an infectious disease. Additional research on the organs detected a pigeon herpesvirus, more specifically the columbid herpes virus 1 (CoHV1). This virus circulates in the (feral) pigeon population without causing too many problems. The animals are often asymptomatic carriers. In some cases (stress, co-infections, …), it can cause illness and mortality in young pigeons. The virus ends up in birds of prey after preying and consuming CoHV1-positive pigeons. Once the virus enters the organs, the bird of prey becomes ill.
Small white spots can be seen on the liver, which were identified histologically as foci of necrosis.
The pigeon herpesvirus is impossible to control in the wild because of the very large population of (feral) pigeons that exchange these viruses. In addition, herpesviruses establish a life-long persistent infection in the host termed latency. These infected birds remain healthy and well. In case of stress, a latent virus can (re-)activate but this does not always translate into visible symptoms. Controlling this virus in the pigeon population is therefore very difficult. Avoiding transmission to birds of prey in the wild is also not obvious. In captive birds of prey, it is strongly advised not to use pigeons as food and to avoid exposure to pigeons in the enclosures as much as possible. In the wild, this is practically impossible.
Wildlife Health Ghent - Surveillance
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