Deer disease warnings

WARNING: EHD AND BLUETONGUE

Our stalking expert Al Gabriel is also a microbiologist and is casting a concerned eye over the channel at deer disease developments in the EU.

The potential emergence of any po tential illnesses in deer is a cause for concern, with a potential for signifi cant impact to the deer industry. The UK is currently facing two major viral diseases that affect deer with neither having a cure: epizootic haemorrhag ing disease (EHD) and bluetongue. Both illnesses are caused by closely related viruses and, unluckily for us, they are spread by midges. Around 150 different species of biting midges capable of spreading the disease are found throughout the UK, with in creasing numbers every year. In the UK, midge season usually runs from April to November. Given the warm and wet start to the year, it is possible that we could see a surge this summer. EHD has never been confirmed in the UK, but its arrival would mark a sig nificant shift in our understanding of climate change and the shape of things to come. Both EHD and bluetongue pose no harm to humans.

EHD

EHD is currently ravaging through cattle and sheep in Spain, Portugal, Italy, and France. The presence of EHD in France opens the rest of Europe. No doubt, Germany is keeping a close eye. Al though the spread of the disease in cattle and sheep has been somewhat slow in France, it might pick up in the coming midge season. In France, compensation payments for culled cattle have already started. The fear that midges might cross the channel into the UK remains a clear and present one. Control of livestock movement from affected regions is already in place. Some of the symptoms include excessive salivation, bleeding, weakness, and lack of appetite. EHD is particularly known in white-tailed deer in the US. The impacts of EHD are far more noticeable in deer, since it causes death within the first week of infection. Cattle are less likely to succumb to the disease. EHD is present in most continents, with significant prevalence in the US, where disease monitoring systems are well developed.

Warmer winters and drier summers are impacting the life cycles of most species

Bluetongue

As for bluetongue, I’m afraid it is already here in the UK. As I’m writing this article, there are currently 116 cases of bluetongue in England on 67 premises and in four counties, all affecting cattle. There are no reported cases in deer in the UK to date. Bluetongue is one of the notifiable diseases in deer. Bluetongue has been confirmed in Kent, Norfolk, and parts of Suffolk. The bluetongue virus has different strains, and a vaccine exists for all strains but one. Unfortunately for us, the one currently spreading in England is type 3, and there are no vaccines for this strain. Bluetongue is considered somewhat mild in deer, but the potential for further spread to cattle via midges is significant. Nasal discharge, reddening in the mouth, nose and eyes, fever, swelling of the face and the tongue are some of the symptoms. It has been 16 years since the last confirmed case in the UK. It is hoped that temporary control zones currently set up in the south of England will help eliminate bluetongue fairly quickly. Like many things these days, even the transfer of disease and pathogens is directly linked to weather changes and global warming. Warmer winters and drier summers are impacting the life cycles of most species and midges are no exception. [Fun fact: there is no elegant way of telling different midge species apart unless you look at the sexual organs under a microscope.] The likelihood that these illnesses will spread across the UK deer population is low but not insignificant. The possible impact to the venison market is of major concern. It must be noted that neither bluetongue nor EHD is passed from animal to animal: a midge bite (other insects can also transmit these diseases) is required to transmit these viruses. Often, improved surveillance highlights events which would have not been noticed in the past. With improved technologies and communication, we are discovering more threats to deer. Depopulating cattle is currently the only means of limiting bluetongue spread. The risk to farmed deer, should EHD get to our shores, is a significant one, given the severity in deer compared to bluetongue. It might affect deer farms already stretched with ongoing economic concerns.

While there is absolutely no need for panic, all stalkers must be fully aware of what to look out for and who to report it to. I would like to take the opportunity to highlight that in England you need to contact the Animal and Plant Health Agency on 03000 200 301. We must always take news such as this with a pinch of salt and pragmatism; no change is necessary in the way deer are managed at the moment. Extra vigilance is warranted for those stalking the Norfolk/ Suffolk areas that have a significant deer population, and stalkers near temporary control zones. There is a real possibility that the first cases of EHD might appear in the next 12 months.