Clinical Signs in Sheep Infected with BTV-8

Clinical signs observed in sheep are usually more severe than those seen in cattle. In the European BTV-8 outbreak, mortality in sheep was high when compared with other BTV outbreaks.

Clinical signs seen in sheep include:

• Pyrexia (raised body temperature) and inappetance were predominant in infected sheep in the BTV-8 outbreak.
• Erosions on the mucosa of mouth and nose
• Mucopurulent (snotty) nasal discharge
• Dyspnoea (difficulty breathing) in severe cases
• Lacrimation (runny eyes) and peri-ocular oedema and petechiae (swollen red eyes)
• Oedema, erythema and ulceration on teats udder and vulva
• Photosensitive-like (severe sunburn) lesions are seen on the skin and there is loss of wool.
• Lameness with interdigital lesions (ulcers between the claws), coronitis (redness and swelling at the top of the hoof) and oedema of the legs

The images below are sheep diagnosed with BTV-8 during the 2006-2007 outbreak in the Netherlands and Germany.