According to the Foreign and Commonwealth office
the main types of incident for which British nationals required consular assistance in Spain in 2006 were for theft and pick-pocketing so be on your alert for street crime and be aware of the threat from terrorism. Since the 2004 Madrid bombings people have been more alert so remember not to leave your luggage unattended and be alert in the Basque region of Spain, which has an active and violent movement.
Check the Foreign and Commonwealth office "Know before you Go" campaign before travelling to Spain.
Rabies is not normally present in Spain (excluding the North African coast) but any type of bite should be assessed by a medical professional. The Foreign and Commonwealth Office confirms that the risk to humans from Avian Influenza is very low in Spain, but you should avoid places where you may come into close contact with domestic, caged or wild birds and ensure poultry and egg dishes are thoroughly cooked.