Mortality in red squirrels (Sciurus vulgaris) associated with exudative dermatitis

Area of Science:

• Veterinary Pathology
• Wildlife Disease Ecology
• Dermatology

Background:

• Red squirrels (Sciurus vulgaris) on the Isle of Wight and Jersey exhibited severe skin lesions.
• The observed dermatitis was exudative and ulcerative, with superficial staphylococcal pyoderma.
• Gross and histopathological lesions shared similarities with squirrelpox virus infections.

Observation:

• Lesions primarily affected the lips, eyelids, and feet.
• Intracytoplasmic inclusions suggestive of poxvirus were noted histologically.
• Electron microscopy and PCR analysis did not detect poxvirus particles or genetic material.
• Mites (Dermacarus sciurinus, Metalistrophorus pagenstecheri) were present but deemed non-pathogenic.

Findings:

• Squirrelpox virus was excluded as the causative agent.
• Pathogenic mites were not identified as the cause of dermatitis.
• The primary etiology of the exudative, ulcerative dermatitis in red squirrels remains unknown.

Implications:

• Further research is needed to identify the cause of dermatitis affecting red squirrels.
• Understanding the etiology is crucial for conservation efforts of Sciurus vulgaris.
• Differential diagnosis for squirrel skin conditions should consider non-viral and non-parasitic causes.