Systematic Veterinary Virology

SYMPTOMS

• Symptoms vary in clinical cases from mild to severe.
• The common symptoms include fever, depression, polypnoea, conjunctivitis, lacrimation, rhinitis, oedema of eyelids and photophobia. The cutaneous eruption begin with erythematous areas especially noticeable in hair or wool-free parts of the body, such as the perineum, inguinal area, scrotum, udder, muzzle, eyelids and axillae which evolve into papules.  
• In papulovesicular form Papules become a white-grey colour, desiccate and form crusts that are easy to remove. Rarely, papules may transform into vesicles. After rupture of vesicles, a thick crust covers the lesions. 
• In nodular form Papules give rise to nodules involving all the layers of the skin and the subcutaneous tissue. Necrosis and sloughing of the nodules leaves a hairless scar.
• In both forms, nodules develop in the lungs causing bronchopneumonia with cough, abundant nasal discharge, depression, anorexia and emaciation. Animals may recover within 20-30 days. Death is frequent when complications like abortion, secondary infections, fly strike, septicaemia and digestive localisation occur.