a wee tip when teaching a dog to jump over barbwire . place some pipe lagging round barbwire first saves any unwanted injuries.
http://cgi.ebay.co.uk/PIPE-LAGGING-15MM-X-13MM-THICK-X-1MTR-QTY-5-MTRS-/260675975652?pt=UK_DIY_Materials_Plumbing_MJ&hash=item3cb17fb9e4