Current situation of the research on hares

This message was updated on December 6^th, 2024; the map has been replaced by a map with the latest updates.

Mortality of hares infected with the myxomatosis-like virus continues. Do not touch the dead animals with bare hands. Although myxomatosis is not a zoonosis, and is therefore not dangerous to humans, dead hares can contain other pathogens that are dangerous to humans, such as tularemia (rabbit fever: https://dwhc.nl/en/ziekten/tularemie/).

Handling carcasses or sick hares

• Sick hare: please report them to the animal ambulance.
• Hare, freshly dead: you can double wrap the hare in plastic and store it in a cool place. Please report them for research (https://dwhc.nl/en/report/form-to-submit-a-dead-animal/). Each day, we check which animals can be collected for research. You will hear from us as soon as possible.
• Hare, dead for over 12 hours: you can double wrap the hare in plastic and put it in the container for residual waste. Please report them for insight in wildlife mortality (https://dwhc.nl/en/report/form-insight-wildlife-mortality/).

To prevent contamination of healthy hares, it is better to not leave dead animals in the field.

Is it the same virus as the myxomatosis virus in rabbits? Is it contagious to rabbits?

DWHC is investigating the background of this disease outbreak in collaboration with colleagues from Germany. They have determined that it concerns the Iberian myxoma variant. (https://www.fli.de/en/news/short-messages/short-message/new-threat-to-the-brown-hare-iberian-myxoma-virus-variant-detected-in-germany-for-the-first-time/)

The exact identification of the virus is still ongoing, we do not know yet whether this strain of the virus is also contagious for (domesticated) rabbits. It is a possibility, but has not yet been determined. The Faculty of Veterinary Medicine advises to always vaccinate captive rabbits against myxomatosis and RHD and to put mosquito-repellent netting around the cage of the captive rabbits.

How did the outbreak start?

It has not yet been determined what caused the current outbreak nor where it originated. The investigation on this is still ongoing.

Are there consequences for the population? What mortality is expected? Have any hares recovered?

We do not yet know whether all hares carrying this virus will eventually become ill and how many of the hares that become ill will eventually die. Some of the hares DWHC examined have died of the myxomatosis-like symptoms. Additionally, in an number of hares other diseases have also been found.

The exact impact of this specific virus on the population is not yet known.

How is the virus transmitted? How do animals get infected?

It is likely that insects (including mosquitoes) play a role in transmission. In rabbits, the myxomatosis virus can also spread from animal to animal via direct contact with infected secretions (via eyes, nose) and sometimes indirectly via contaminated materials in the environment (https://www.woah.org/en/disease/myxomatosis/).

Where in the country is the virus found?

So far, most reports of sick hares with this myxomatosis-like symptoms are found in De Achterhoek. However, we also see sick hares with the same symptoms in other parts of Gelderland as well as other provinces.

How many hares have been examined?

In the period from early August to November 18^th, 45 hares were collected for research at DWHC. One hare was not suitable for research. Many collected hares have myxomatosis-like symptoms, while some do not. In all hares, with and without myxomatosis-like symptoms, other diseases were also found.