Advice Note: Dead Red Squirrels & Squirrelpox Virus

This advice note is being issued to provide up to date information in the light of recent changes at

the Animal Health & Veterinary Laboratories Agency (AHVLA), Penrith, Cumbria.

Changes to red squirrel examinations at the AHVLA

The AHVLA, through the Defra funded Disease of Wildlife Scheme (DoWS), have monitored squirrel

disease in England and Wales for almost 30 years. Unfortunately due to priorities in wildlife diseases

elsewhere in England and Wales, and budgetary constraints, the AHVLA have reluctantly had to cut

back on squirrel examinations. They are asking that no squirrels (red or grey) are submitted to the

office at Calthwaite, Penrith, without prior consultation. Anyone finding a dead red squirrel is

advised to contact a member of the RSNE team in Cumbria or Northumberland, or to contact their

local red squirrel volunteer group. Contact details are provided at the end of this advice note. Please

note, for dead red squirrels in the Merseyside & West Lancashire area, contact one of the Lancashire

Wildlife Trust officers for further advice.

Causes of death

Post mortems carried out by the AHVLA have revealed a number of regular causes of death in red

squirrels. In addition to road-kill and predator attack, there have been new emerging diseases that

have effected local populations, in particular adenovirus and louse infestations. However, the most

significant threat to red squirrels is from squirrelpox virus infection. Examination of dead reds has

meant that the extent and northerly movement of the virus over the last 20 years is well

documented. Maps representing this can be found in the appendix to this advice note. Further

information on SQPV can be found in the RSNE Advice Note: Squirrelpox Virus.

In northern England we have also learnt that the virus can reoccur locally in interface areas where

reds and greys continue to come into contact. Significantly, in areas where there have been

outbreaks of the disease, red populations have gone on to recover. The key to this recovery is

management and containment of the virus, and crucially, sustained grey squirrel control in these

areas so that greys are not allowed the opportunity to colonise woodlands where red squirrel

numbers have dwindled.

SQPV is relatively easy to identify, as animals develop distinctive lesions around exposed areas of

skin such as the eyes, mouth, nose and paws. If a member of the public spots an animal showing

these signs, or finds a carcass and SQPV is suspected, please contact a member of the RSNE team or

the local red squirrel volunteer group for further advice. Other diseases, for example adenovirus,

may show no signs. If there are unexplained mortalities in a location, then again contact a member

of the RSNE team, or your local squirrel group for further advice.

Future red squirrel examinations

The AHVLA DoWS may be able to carry out a small number of examinations on dead red squirrels.

However priority must be given to emerging cases of suspected SQPV in new areas, or in current red

squirrel reserves. RSNE staff will make an informed decision on pri ority cases and liaise with the

AHVLA to organise tests. Please contact RSNE directly or via your local red squirrel group to discuss.

It may also be possible to pay privately for SQPV testing at the AHVLA. This is currently around £50

per examination. Please note a full post mortem examination on a dead red squirrel will cost in the

region of £150. We are extremely privileged to have received this service for free, and acknowledge

the contribution that Defra and the AHVLA have made to date in providing this service.

Recording of suspected SQPV cases

To date, the recording and mapping of cases has been possible following the confirmation of SQPV.

In the absence of regular testing, it would be prudent to continue to record suspected occurrence of

the virus. RSNE in conjunction with local red squirrel groups will endeavour to maintain a database

of suspected cases, to include the date and location of carcasses, and if possible, photographic

evidence. In this way, we can continue to monitor suspected outbreaks.

Disposal of dead red squirrels

Anyone discovering a dead red squirrel in the wild should take sensible precautions when dealing

and disposing of the carcass, particularly if disease is suspected. If possible, carcasses should be

buried in the same woodland location in which they are found, and not moved to any other location.

Please handle bodies carefully, and preferably wearing gloves, or by placing a plastic bag over the

hand. If the animal shows lesions, symptomatic of SQPV, then bury the animal or leave alone to be

scavenged naturally. There is no increased risk to the local population of re d squirrels in following

either of these methods. The virus is unlikely to survive for long in damp conditions.

If it is not possible to leave or bury a carcass in the same location, then the body could be

incinerated or placed in landfill, but please wrap the body in at least two plastic bags if doing so.

Acknowledgements

The AHVLA Disease of Wildlife Scheme would like to thank all conservation bodies for their support

in the scientific monitoring of red squirrel health. RSNE acknowledge Defra and the AHVLA for

funding and delivering this work to date.

Contact Details

For further advice on dealing with red squirrel carcasses, or managing SQPV please contact a

member of the RSNE team http://www.rsne.org.uk/contact-us or contact your local volunteer red squirrel group http://www.northernredsquirrels.org.uk/members.htm

Appendix: SQPV Maps 1994-2013

The spread of squirrelpox virus in Cumbria 1994-2013. The map above show positive cases as confirmed by

the AHVLA in 2km squares over three time periods: 1994-2004, 2004-2008 and 2008-2013. The map suggests

movement of the virus over space and time from south Cumbria through the central Lakes, and up the west

coast. The final period (2008-2013) shows further occurrence of the disease in multiple directions. There was a

significant increase in the number and new locations of confirmed cases between 2008 and 2013. This

coincided with greater public awareness, an increase in people actively involved in red squirrel conservation

on the ground and consequently an increase in the number of animals submitted to the AHVLA for testing.

Please note: the map il lustrates new locations (per 2km square) in order to show the geographical spread of

the virus over time: there are several cases where SQPV has been recorded in the same location in either two

or all three of these periods.

The spread of squirrelpox virus in County Durham, Tyne & Wear and Northumberland 1994 to 2013 . The

maps show positive cases as confirmed by the AHVLA in 2km squares over three time periods: 1994-2004,

2004-2008 and 2008-2013. New locations (per 2km square) are shown using different colour shading. The

maps suggest movement of the virus over space and time in a northerly direction, advancing up the North

Tyne area and throughout eastern Northumberland. The final period shows the advance of the virus in recent

years to north Northumberland. Please note the map il lustrates new locations (per 2km square) in order to

show the geographical spread of the virus over time: there are several cases where SQPV has been recorded in

the same location in either two or all three of these periods.