FOLLOWING the first detection in 2017 of pathogenic squirrelpox virus (SQPV) infection in red squirrels (Sciurus vulgaris) sympatric with grey squirrels (Sciurus carolinensis) in the coastal woodlands near Bangor in Gwynedd, north Wales,1 sporadic cases have continued to be detected. Disease has centred around woodland situated near rail/road bridges which link the mainland to the adjacent island of Anglesey. The island contains the largest red squirrel population in Wales and grey squirrels are not established there.

Red squirrels have been present in mainland coastal woodlands since 2009 after naturally recolonising from Anglesey. A small subpopulation persisted after the initial 2017 squirrelpox outbreak, and there have been three further cases of SQPV detected. One occurred in the Eithinog Nature Reserve,2 and a further case was uniquely detected by a conservation dog while lockdown was in operation and access restricted for investigation purposes.3

Here we report on the latest local SQPV case discovered on 30 January 2021. This was an adult male caught during licensed routine population monitoring. The individual had erosive skin lesions associated with overlying dark brown crusty material present on the chin, lips and around both eyes (Fig 1). There were areas of hair loss on the bridge of the nose, overlying the thoracic inlet and on three digits of the left forefoot and two digits of the right hindfoot. The animal died a few hours after discovery and gross postmortem examination by the APHA Diseases of Wildlife Scheme at the Veterinary Investigation Centre, Shrewsbury, revealed enlargement of the spleen. Staphylococcus species were isolated from skin lesions on the chin and SQPV infection was confirmed by virus particle detection using transmission electron microscopy of lesion material at the APHA's Weybridge laboratory. Staphylococcus aureus was isolated from the spleen, indicating a bacteraemic infection.